Comparison of Smith/Nomarski DIC and PlasDIC

A: Smith/Nomarski Differential Interference Contrast. The action of Nomarski Prism 1 (Nom1) and the Köhler condenser creates two "difference image plane waves" from a single polarized wave (from Pol). These two waves create two phase-distorted images ("difference images") after passing through a transparent object with a refractive index different from the surrounding medium. The lateral distance between wave pairs is called shear ("d") and the phase offset between wave pairs is called Sample Phasing (upper case delta). A second, inverted Nomarski prism (Nom2) performs two functions: 1) it induces further phasing between the two wavefronts relative to its lateral position, and 2) it recombines the two sheared wavefronts into overlapping wavefronts (removes shear). Since the wavefronts are vibrating 45° relative to the Analyzer, this second polarizer interacts equally with both wavefronts, "folding" the two vibrational planes into a single plane. It's at this point, the Analyzer, that wave interference occurs. Both prisms are set at 45° to the orientation of the two polarizers. This allows both the o- and e-wavefronts to interact at the Analyzer.

B: PlasDIC works under the same general concept as DIC (above) except that the Polarizer and Nomarski-modified Wollaston prism and Analyzer are placed past the (birefringent) specimen has induced a phase distortion to the impinging wavefront. A Nomarski-modified Wollaston prism splits the wavefront into two spatially separated wavefronts (d), and still adds bias (Gamma) which then pass through a polarizer. Since the Prism is oriented at 45° to the plane of the Analyzer, both wavefronts are modified by the Analyzer to vibrate in the same plane. Interference occurs only when the two wavefronts become coherent at the Intermediate Image Plane (not shown). Unfortunately PlasDIC requires a slit illuminator (oriented parallel to the prism) and low magnification/NA objectives, thus magnification is limited to <40x objective magnification. However, it is an excellent optical technique for imaging cells growing on plastic petri plates.

Comparison of Smith/Nomarski DIC and PlasDIC

A: Smith/Nomarski Differential Interference Contrast. The action of Nomarski Prism 1 (Nom1) and the Köhler condenser creates two "difference image plane waves" from a single polarized wave (from Pol). These two waves create two phase-distorted images ("difference images") after passing through a transparent object with a refractive index different from the surrounding medium. The lateral distance between wave pairs is called shear ("d") and the phase offset between wave pairs is called Sample Phasing (upper case delta). A second, inverted Nomarski prism (Nom2) performs two functions: 1) it induces further phasing between the two wavefronts relative to its lateral position, and 2) it recombines the two sheared wavefronts into overlapping wavefronts (removes shear). Since the wavefronts are vibrating 45° relative to the Analyzer, this second polarizer interacts equally with both wavefronts, "folding" the two vibrational planes into a single plane. It's at this point, the Analyzer, that wave interference occurs. Both prisms are set at 45° to the orientation of the two polarizers. This allows both the o- and e-wavefronts to interact at the Analyzer.

B: PlasDIC works under the same general concept as DIC (above) except that the Polarizer and Nomarski-modified Wollaston prism and Analyzer are placed past the (birefringent) specimen has induced a phase distortion to the impinging wavefront. A Nomarski-modified Wollaston prism splits the wavefront into two spatially separated wavefronts (d), and still adds bias (Gamma) which then pass through a polarizer. Since the Prism is oriented at 45° to the plane of the Analyzer, both wavefronts are modified by the Analyzer to vibrate in the same plane. Interference occurs only when the two wavefronts become coherent at the Intermediate Image Plane (not shown). Unfortunately PlasDIC requires a slit illuminator (oriented parallel to the prism) and low magnification/NA objectives, thus magnification is limited to <40x objective magnification. However, it is an excellent optical technique for imaging cells growing on plastic petri plates.

PlasDIC

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by crb5 » Tue Dec 29, 2020 12:00 am

A colleague of mine recently obtained a Leitz Laborlux S scope on eBay which came with a PlasDIC option. He asked me to take a look at it and try it out. The scope has a slider above the objectives which appears to be a prism+polarizer. I was expecting a second polariser above this, as in the Zeiss PlasDIC system http://www.zebrasc.com/UpImages/200912/ ... 132510.pdf but there is no port available. There is a 3.5mm slit aperture in a plastic holder which sits centrally over the light source, and immediately above this there is a rotatable polarizer. I thought PlasDIC referred to the option of being able to use PLASTIC sample dishes and for this there should not be any polarizers in the illumination path - but on closer investigation I see other authors (theoreticians at least!) have described the arrangement above as PlasDIC e.g. https://onlinelibrary.wiley.com/doi/abs ... /jmi.12248. It therefore seems some people use PlasDIC to describe the situation where a slit aperture is used. There is no indication on the prism slider as to which objective it is designed for. The scope has 4x, 10x and 40x 160/0.71 objectives plus a 25x 170/0.71 objective - the latter suggests the scope has been subject to add-ons, nor is it clear where the PlasDIC slider came from or if this is a DIY modification. Any advice on how to use such a system? I did not get particularly impressive DIC-like effects with an onion skin test sample as I rotated the slit+polarizer (i.e. oblique illumination seemed to work just as well).

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lightshape

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Re: PlasDIC

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by lightshape » Sat Jan 09, 2021 8:36 pm

Hi,

you are right regarding polarizer/analyzer position and PlasDIC.

For PlasDIC you will usually find objective specific prisms and the polarizer and analyzer are both placed behind the sample.

There once was an article in a german microscope magazine:

https://www.zobodat.at/pdf/Mikrokosmos_72_0001.pdf

..page 301

Guess this could in fact be a DIY slit DIC you've got.

In such a setup, one prism might work well for many different magnification combinations.

But, you will have to adjust the size of the slit to match the magnifications or even more specific, to the used prism and objectives themselves for best results.

Some measures to begin experimenting with slits:

10x 1-2mm

40x 3-6mm

100x 5-10mm

For the slit, once adjusted, you don't want to rotate it at all.

It needs to be perfectly aligned with the optical axis of the DIC Prism.

Which is 45° in respect to the axis of the polarizer.

Also, as far as i know, the slits positioning then needs to be covering the extinction pattern of the Prism (the black slit you will see on the DIC prism placed between polarizer/analyzer in extinction).

Has the analyzer above the Prism been fixed?

If so, chance are great it will still be correctly aligned to the prism, this would already make things little easier to start.

Hope this takes you a little further.

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crb5

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Re: PlasDIC

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by crb5 » Sat Jan 09, 2021 11:16 pm

Thanks for the information and article. This does suggest the supplied slit is designed to be used with the 40x objective and knowing the slit should be 45 degrees to the polariser is helpful. The analyzer and wollaston prism in the imaging path are fixed, so that just leaves the illumination polarizer to be adjusted.

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Scarodactyl

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Re: PlasDIC

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by Scarodactyl » Sun Jan 10, 2021 12:21 am

Please share some pictures if you get it up and running. Epi DIC systems are way easier to find bargains on than transmitted, so this technique seems like it should be of great interest if it can deliver.

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Re: PlasDIC

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by PeteM » Sun Jan 10, 2021 12:29 am

Curious if this microscope came from a Canadian Ebay seller? I've seen a number of microscopes described as "DIC" or Plas-DIC" from that source that look to have been cobbled together, with not quite enough parts. Could be it's just a sort of oblique setup, maybe with a prism added to add some color?? The same seller has advertised as "phase contrast" an objective not so marked and with no phase ring looking through.

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Re: PlasDIC

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by Elapid » Tue Mar 02, 2021 11:49 am

I agree, the Canadian seller seems to specialize in “pseudo-DIC” microscopes which give a false impression of DIC by using polarization in one form or another. If you look at one of seller’s scopes on eBay you will see a photo in the lineup which supposedly was taken thru the scope currently for sale. It is a true DIC photomicrograph but the very same photo appears with every one of seller’s listed DIC scopes! I discovered this the hard way. I wish eBay would crack down on this sort of thing but it would be very difficult for a buyer to initiate.

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Re: PlasDIC

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by apochronaut » Wed Mar 03, 2021 9:33 pm

PeteM wrote: ↑

Sun Jan 10, 2021 12:29 am

Curious if this microscope came from a Canadian Ebay seller? I've seen a number of microscopes described as "DIC" or Plas-DIC" from that source that look to have been cobbled together, with not quite enough parts. Could be it's just a sort of oblique setup, maybe with a prism added to add some color?? The same seller has advertised as "phase contrast" an objective not so marked and with no phase ring looking through.

There are phase contrast objectives that do have a phase ring that is not visible to the eye.

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Re: PlasDIC

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by PeteM » Wed Mar 03, 2021 10:19 pm

Could be. But the exterior markings on this one (being sold as phase) said nothing about phase, ph, ph1, dm, etc. etc. I was inclined towards skepticism - warranted or not. When asked the seller basically said "I don't know . . ."

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Re: PlasDIC

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by LouiseScot » Sun Mar 07, 2021 8:59 pm

There's currently a plasDIC slider on Ebay and from Denmark. Says it's for a 20x objective with coverslip correction. If I thought I could get it to work I'd be tempted to buy it and have a go!

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Placozoa

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Re: PlasDIC

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by Placozoa » Mon Mar 08, 2021 4:51 am

https://www.ebay.at/itm/PlasDIC-slider- ... SwlTBeI0~7

Something like that?

Im reasonably sure you need a matching prism in your condenser for it to work. The DIC prisms may also need to be preceded by a polarizer, but that may be built in to the condenser. Others would know better, I dont have DIC.

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Re: PlasDIC

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by LouiseScot » Mon Mar 08, 2021 8:27 am

Placozoa wrote: ↑

Mon Mar 08, 2021 4:51 am

https://www.ebay.at/itm/PlasDIC-slider- ... SwlTBeI0~7

Something like that?

Im reasonably sure you need a matching prism in your condenser for it to work. The DIC prisms may also need to be preceded by a polarizer, but that may be built in to the condenser. Others would know better, I dont have DIC.

Yeah, that's the one. I was looking at it from the point of view of the figures showing the principles here: http://www.zebrasc.com/UpImages/200912/ ... 132510.pdf

They suggest a slit then a polariser/prism/analyser above the objective, which could be done on my customisable rail system. But, together with a matching objective, it would still be a lot of money to risk! Though great if it worked

:)

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Re: PlasDIC

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by apochronaut » Mon Mar 08, 2021 11:51 am

PlasDIC is just one named system that Zeiss named and I'm pretty sure patented. It was derived from the designs of Max Pluta upon which PZO's several interference contrast systems were based. Zeiss used a workaround of the original system and came up with PlasDIC.

PlasDIC uses a slit diaphragm below the condenser and a cemented polarizer wollaston prism slider above the objective followed by an analyzer. Pluta's design used a polarizer and variable slit condenser below the condenser , then a prism and analyzer above the objective. There was also a 3-D condensing system by Goerz that used a polarizer and some sort of prism/slit condenser below the stage and an analyzer above the objective. Both Pluta's and Goerz' systems could be operated at high magnification, whereas PlasDIC seems to have a limit around a 40X objective. That may be due to the targeted application of plastic dishes. Perhaps with glassware of a higher specification , one could go higher with PlasDIC.

There are several ways of getting a budget DIC system going but they all seem to hinge on the utilization of a slit diaphragm BELOW the condenser. The PZO version is deformable and the Goerz version rotatable. Aligning the slit with the polarizer is necessary. In the PZO version the polarizer rotates against the diaphragm.

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Re: PlasDIC

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by LouiseScot » Mon Mar 08, 2021 12:59 pm

apochronaut wrote: ↑

Mon Mar 08, 2021 11:51 am

PlasDIC is just one named system that Zeiss named and I'm pretty sure patented. It was derived from the designs of Max Pluta upon which PZO's several interference contrast systems were based. Zeiss used a workaround of the original system and came up with PlasDIC.

PlasDIC uses a slit diaphragm below the condenser and a cemented polarizer wollaston prism slider above the objective followed by an analyzer. Pluta's design used a polarizer and variable slit condenser below the condenser , then a prism and analyzer above the objective. There was also a 3-D condensing system by Goerz that used a polarizer and some sort of prism/slit condenser below the stage and an analyzer above the objective. Both Pluta's and Goerz' systems could be operated at high magnification, whereas PlasDIC seems to have a limit around a 40X objective. That may be due to the targeted application of plastic dishes. Perhaps with glassware of a higher specification , one could go higher with PlasDIC.

There are several ways of getting a budget DIC system going but they all seem to hinge on the utilization of a slit diaphragm BELOW the condenser. The PZO version is deformable and the Goerz version rotatable. Aligning the slit with the polarizer is necessary. In the PZO version the polarizer rotates against the diaphragm.

Thanks for the info! It wouldn't be difficult to arrange a slit. It's not clear to me what the relationship is between the objective and the prism. In the Ebay ad you can see it specifies a 20x objective -> 'PlasDIC slider for LD PN 20x/0.40 corr' which is a long working distance objective that has a cover slip corrector (perhaps for an inverted microscope?). Also quite expensive in itself, and it's not clear to me whether that should be a phase contrast (Ph1) version? I'd have thought phase contrast was quite separate from plasDIC?

So I presume a standard 20x objective would do, but it's also implied that you'd need a separate prism slider for each objective? That wouldn't be good but, if I had such a thing, I'd probably only use it/them with 20x and 40x.

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Re: PlasDIC

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by viktor j nilsson » Mon Mar 08, 2021 1:33 pm

The two key variables to be optimized is the shear angle and location of the interference fringe. The shear angle is optimized based on the NA of the objective, with narrower angles for high NA/high magnification objectives. I think that it is correct to say that this is because you want the separation created by the shear angle to be smaller than the minimum resolvable feature of the objective. The location of the interference fringe is optimized so that its location coincides with the back focal plane of the objective.

So in general, 20x prism = larger shear angle, interference fringe closer to the prism; 40x prism = smaller shear angle, interference fringe further from the prism.

In reality, these systems are fairly tolerant. You could probably pick almost any 10x,20x or 40x prism (epi, plasDIC or transmitted), a polarizer and test some differently-sized slits at the back focal plane of the condenser, and you would get a pretty decent plasDIC effect. If you can move the prism up and down a bit to match the back focal plane - even better.

I do not think that the prism on eBay is necessarily better suited for DIY plasDIC than other nomarski prisms intended for other dic methods.

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Re: PlasDIC

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by LouiseScot » Mon Mar 08, 2021 1:37 pm

viktor j nilsson wrote: ↑

Mon Mar 08, 2021 1:33 pm

The two key variables to be optimized is the shear angle and location of the interference fringe. The shear angle is optimized based on the NA of the objective, with narrower angles for high NA/high magnification objectives. I think that it is correct to say that this is because you want the separation created by the shear angle to be smaller than the minimum resolvable feature of the objective. The location of the interference fringe is optimized so that its location coincides with the back focal plane of the objective.

So in general, 20x prism = larger shear angle, interference fringe closer to the prism; 40x prism = smaller shear angle, interference fringe further from the prism.

In reality, these systems are fairly tolerant. You could probably pick almost any 10x,20x or 40x prism (epi, plasDIC or transmitted), a polarizer and test some differently-sized slits at the back focal plane of the condenser, and you would get a pretty decent plasDIC effect. If you can move the prism up and down a bit to match the back focal plane - even better.

I do not think that the prism on eBay is necessarily better suited for DIY plasDIC than other nomarski prisms intended for other dic methods.

But other DIC uses two prisms and anything labelled 'Nomarski' seems to be very expensive!

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Re: PlasDIC

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#16

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by viktor j nilsson » Mon Mar 08, 2021 1:47 pm

LouiseScot wrote: ↑

Mon Mar 08, 2021 1:37 pm

viktor j nilsson wrote: ↑

Mon Mar 08, 2021 1:33 pm

The two key variables to be optimized is the shear angle and location of the interference fringe. The shear angle is optimized based on the NA of the objective, with narrower angles for high NA/high magnification objectives. I think that it is correct to say that this is because you want the separation created by the shear angle to be smaller than the minimum resolvable feature of the objective. The location of the interference fringe is optimized so that its location coincides with the back focal plane of the objective.

So in general, 20x prism = larger shear angle, interference fringe closer to the prism; 40x prism = smaller shear angle, interference fringe further from the prism.

In reality, these systems are fairly tolerant. You could probably pick almost any 10x,20x or 40x prism (epi, plasDIC or transmitted), a polarizer and test some differently-sized slits at the back focal plane of the condenser, and you would get a pretty decent plasDIC effect. If you can move the prism up and down a bit to match the back focal plane - even better.

I do not think that the prism on eBay is necessarily better suited for DIY plasDIC than other nomarski prisms intended for other dic methods.

But other DIC uses two prisms and anything labelled 'Nomarski' seems to be very expensive!

Louise

Yes, but the upper prism in a transmitted Nomarski DIC system needs to fulfill the exact same requirements: a shear angle that matches the NA of the objective, and an interference fringe that matches the location of the back focal plane. So there's nothing special about plasDIC prisms.

The plasDIC is simple to DIY, since those are the only parameters you need to optimize (well that, and the width of the slit). And it's probably not even super critical to get them just right.

In a true Nomarski DIC system, you also need to make sure that the width of the interference bands created by the condenser prism (after passing through both the condenser and the objective) matches the width of the Interference bands created by the upper prism. And that's a whole lot more complicated.

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LouiseScot

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Re: PlasDIC

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#17

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by LouiseScot » Mon Mar 08, 2021 1:54 pm

viktor j nilsson wrote: ↑

Mon Mar 08, 2021 1:47 pm

LouiseScot wrote: ↑

Mon Mar 08, 2021 1:37 pm

viktor j nilsson wrote: ↑

Mon Mar 08, 2021 1:33 pm

The two key variables to be optimized is the shear angle and location of the interference fringe. The shear angle is optimized based on the NA of the objective, with narrower angles for high NA/high magnification objectives. I think that it is correct to say that this is because you want the separation created by the shear angle to be smaller than the minimum resolvable feature of the objective. The location of the interference fringe is optimized so that its location coincides with the back focal plane of the objective.

So in general, 20x prism = larger shear angle, interference fringe closer to the prism; 40x prism = smaller shear angle, interference fringe further from the prism.

In reality, these systems are fairly tolerant. You could probably pick almost any 10x,20x or 40x prism (epi, plasDIC or transmitted), a polarizer and test some differently-sized slits at the back focal plane of the condenser, and you would get a pretty decent plasDIC effect. If you can move the prism up and down a bit to match the back focal plane - even better.

I do not think that the prism on eBay is necessarily better suited for DIY plasDIC than other nomarski prisms intended for other dic methods.

But other DIC uses two prisms and anything labelled 'Nomarski' seems to be very expensive!

Louise

Yes, but the upper prism in a transmitted Nomarski DIC system needs to fulfill the exact same requirements: a shear angle that matches the NA of the objective, and an interference fringe that matches the location of the back focal plane. So there's nothing special about plasDIC prisms.

The plasDIC is simple to DIY, since those are the only parameters you need to optimize (well that, and the width of the slit). And it's probably not even super critical to get them just right.

In a true Nomarski DIC system, you also need to make sure that the width of the interference bands created by the condenser prism (after passing through both the condenser and the objective) matches the width of the Interference bands created by the upper prism. And that's a whole lot more complicated.

Yeah, I wouldn't attempt any kind of DIY full DIC, lol.

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Elapid

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Re: PlasDIC

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#18

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by Elapid » Sat Mar 13, 2021 1:41 pm

I spent years searching for a “cheap” DIC scope and wasted time and money without any real results. Last year I decided to bite the bullet and spend the money to get a true DIC microscope. Now I realize that true DIC microscopy is a thing of beauty, DIC photomicrographs can be quite stunning, especially with focus stacking. But DIC is complex and exacting. I’ve noticed that the Chinese microscope companies don’t seem to offer it. My scope requires a polarizer below the condenser, prisms in the condenser for each objective, and then the prism/polarizer analyzer below the eyepieces. If any of these components are missing or not properly adjusted then DIC is lost. Unfortunately this is all very expensive to manufacture and expensive to buy even on the used market. But worth the wait. At one point I let myself be deceived into buying a pseudo-DIC scope, but at least it was a good learning experience. Finally getting the real thing was worth the wait.

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Re: PlasDIC

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#19

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by LouiseScot » Sat Mar 13, 2021 2:05 pm

Elapid wrote: ↑

Sat Mar 13, 2021 1:41 pm

I spent years searching for a “cheap” DIC scope and wasted time and money without any real results. Last year I decided to bite the bullet and spend the money to get a true DIC microscope. Now I realize that true DIC microscopy is a thing of beauty, DIC photomicrographs can be quite stunning, especially with focus stacking. But DIC is complex and exacting. I’ve noticed that the Chinese microscope companies don’t seem to offer it. My scope requires a polarizer below the condenser, prisms in the condenser for each objective, and then the prism/polarizer analyzer below the eyepieces. If any of these components are missing or not properly adjusted then DIC is lost. Unfortunately this is all very expensive to manufacture and expensive to buy even on the used market. But worth the wait. At one point I let myself be deceived into buying a pseudo-DIC scope, but at least it was a good learning experience. Finally getting the real thing was worth the wait.

PlasDIC is a genuine contrast enhancement technique developed by Zeiss https://www.emerald.com/insight/content ... /full/html

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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crb5

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Re: PlasDIC

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#20

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by crb5 » Sat Mar 13, 2021 3:58 pm

LouiseScot wrote: ↑

Sat Mar 13, 2021 2:05 pm

PlasDIC is a genuine contrast enhancement technique developed by Zeiss https://www.emerald.com/insight/content ... /full/html

This takes us back to my opening question. The Zeiss PlasDIC system has no polarizing components in the illumination/condenser pathway which allowed PLAStic dishes to be used with samples (the technique was developed with in vitro fertilisation in mind). However, the add-on version on my colleague's Leitz Laborlux S scope had a polarizer and slit which sits above the light source and precludes the use of plastic dishes. I subsequently found that this arrangement has also been called PlasDIC in some literature and I wondered how this could be. This same colleague has now bought a Nikon Microphot FXA with Nomarkski DIC and seems very pleased with it. Me, I'm sticking with my Amscope 120 and Dodt contrast for free.

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Re: PlasDIC

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#21

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by LouiseScot » Sat Mar 13, 2021 4:35 pm

crb5 wrote: ↑

Sat Mar 13, 2021 3:58 pm

LouiseScot wrote: ↑

Sat Mar 13, 2021 2:05 pm

PlasDIC is a genuine contrast enhancement technique developed by Zeiss https://www.emerald.com/insight/content ... /full/html

This takes us back to my opening question. The Zeiss PlasDIC system has no polarizing components in the illumination/condenser pathway which allowed PLAStic dishes to be used with samples (the technique was developed with in vitro fertilisation in mind). However, the add-on version on my colleague's Leitz Laborlux S scope had a polarizer and slit which sits above the light source and precludes the use of plastic dishes. I subsequently found that this arrangement has also been called PlasDIC in some literature and I wondered how this could be. This same colleague has now bought a Nikon Microphot FXA with Nomarkski DIC and seems very pleased with it. Me, I'm sticking with my Amscope 120 and Dodt contrast for free.

I think, as Apo pointed out, there are several versions of the idea. Much as I'd like proper DIC I can't afford it. Much as I'd like to experiment with some form of plasDIC, that's not cheap either, and I don't think I'd want to risk spending a fair bit of money on experimenting. I just posted the comment above to indicate that plasDIC is a genuine technique. I doubt I'll be pursuing it any further myself but would be interested if someone else does achieve decent results with it :)

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Re: PlasDIC

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#22

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by Scarodactyl » Sat Mar 13, 2021 11:18 pm

There's an epi dic slider attachment for a balplan available for like 300 bucks on some dealer's site. My own dic balplan gives very respectable epi DIC, similar to an Olympus bh2 era system, so I suspect it would be a good candidate for experimentation.

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LouiseScot

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Re: PlasDIC

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#23

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by LouiseScot » Sat Mar 13, 2021 11:25 pm

Scarodactyl wrote: ↑

Sat Mar 13, 2021 11:18 pm

There's an epi dic slider attachment for a balplan available for like 300 bucks on some dealer's site. My own dic balplan gives very respectable epi DIC, similar to an Olympus bh2 era system, so I suspect it would be a good candidate for experimentation.

That's only for opaque subjects though?

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Re: PlasDIC

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#24

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by Scarodactyl » Sun Mar 14, 2021 1:02 am

As configured yes, but if you put it on a transmitted light balplan (also not too expensive to get) it would probably be a good platform for experimenting with home made plasdic. I mwntion its epi performance only to establish it is a legit (if obscure) DIC system with a legit prism slider.

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Dubious

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Re: PlasDIC

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#25

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by Dubious » Sat Jun 12, 2021 7:18 pm

So, I am confused. In this Ebay listing for a Reichert MicroStar IV with a PlasDIC slider above the objective turret (presumably the slit diaphram and polarizer are somewhere below?) is that an original Reichert option or something the microscope was modified for later that is unlikely to deliver DIC?

https://www.ebay.com/itm/264388794011?h ... SwmrVdH6y0

PlasDIC sounds like a somewhat forgiving type of DIC, more suited for a general application microscope. I'm surprised the Chinese manufactures aren't in the DIC market, but maybe it's a small market.

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Re: PlasDIC

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#26

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by Scarodactyl » Sat Jun 12, 2021 7:38 pm

That guy uses thr same "dic" photo for every listing from what I can see. I would never buy from him.

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Re: PlasDIC

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#27

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by dtsh » Sat Jun 12, 2021 10:07 pm

Dubious wrote: ↑

Sat Jun 12, 2021 7:18 pm

So, I am confused. In this Ebay listing for a Reichert MicroStar IV with a PlasDIC slider above the objective turret (presumably the slit diaphram and polarizer are somewhere below?) is that an original Reichert option or something the microscope was modified for later that is unlikely to deliver DIC?

https://www.ebay.com/itm/264388794011?h ... SwmrVdH6y0

PlasDIC sounds like a somewhat forgiving type of DIC, more suited for a general application microscope. I'm surprised the Chinese manufactures aren't in the DIC market, but maybe it's a small market.

I can't seem to find the thread, but there's a thread here where that very microscope gets discussed. While there are Nomarski DIC options for the 410, this one seems to be some sort of amalgamation of parts of various scopes, the nose appears to be a series 10 for example, that suggest it's someone's custom cobbling. I don't know enough to evaluate if it *works* or not, but I feel confident in saying it's not an original Reichert/Leica/Cambridge/AO option.

Edit: I recall the low effort spray paint job on the nose not instilling confience in attention to detail either. Still, it could work for all I know, but I'd be asking a lot of questions!

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Re: PlasDIC

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#28

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by Dubious » Mon Jun 14, 2021 3:11 am

Looking at the photos again, I see what you mean. And I haven't been able to find any photos of new models equipped like that. Still, it would be great if some refurbisher had found an (almost) economical way to add plasDIC to the microscope, so after I know more about plasDIC, I may ask him those questions.

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Re: PlasDIC

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#29

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by Scarodactyl » Mon Jun 14, 2021 3:55 am

Look at his feedback too.

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Re: PlasDIC

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#30

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by apochronaut » Mon Jun 14, 2021 3:36 pm

I think what is being forgotten here is that at a certain point in time, the Buffalo factory had a best before date, or a limited shelf life, as it were. It was producing Microstar IV and Diastars until about 2001, ATC 2000s until somewhat later but the factory was sold. It continued to do service afterwards and the ATC 2000 production went to India. .They no doubt had stock on hand of all kinds of items at the end. Some, I know for sure ended up at various dealers because I have seen it and some of it for sure was sold off by Reichert Technologies, which continued in Opthalmic research and equipment development as a separate company in the factory.

Some of it, I am pretty sure none of you even know existed, such as Hoffman objectives.

They never made a series 100 DIC: probably some prototypes though, and they only sold about 20 series 21 DIC scopes, so that probably soured them on DIC during the 100 series era. They might have had series 10 slider equipped nosepieces around and the condenser under that 410 looks suspiciously like one I have seen on a legitimate 420 DIC scope.

Whether the factory threw those components together at the end of the run : after all, it would have made sense to liquidate as much as possible, or someone bought all the equipment and assembled the system makes some difference. A factory hybrid might well work pretty good, a kind if d.i.y. job, maybe yes, maybe no. There is no reason to suspect not though, except based on the odd nature of the seller's various listings. Maybe he is a mad DIC scientist, toiling away in the lonely basement of a former 17th century monastery in La Belle Province, unrecognized, unappreciated, on the verge of a breakthrough, in French: if only he had a chance!

Those look like real AO parts, just kind of like they had been assembled in a Renault factory. I'd like to try one out but not for 1000.00.

Slit Interference Contrast

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#1

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by lightshape » Thu Jan 14, 2021 7:09 pm

Hi,

had to give it a try after reading the PlasDIC post.

No idea about the origin of the Prism i've used, had it around for a while.

Just some tape for the slit to begin.

Tried on a Zeiss Jena Jenamed scope.

IMG_7295.JPG

IMG_7295.JPG (71.93 KiB) Viewed 1743 times

First impressions, slit approx. 3.5 mm, 50x objective.

Open aperture:

P1140895.jpg

P1140895.jpg (102.87 KiB) Viewed 1743 times

Slit aperture:

P1140896.jpg

P1140896.jpg (131.83 KiB) Viewed 1743 times

SlitDIC:

P1140897.jpg

P1140897.jpg (139.28 KiB) Viewed 1743 times

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Re: Slit Interference Contrast

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#2

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by lightshape » Thu Jan 14, 2021 7:11 pm

Second impression, slit approx 5.5mm:

Open:

P1140901.jpg

P1140901.jpg (82.47 KiB) Viewed 1741 times

Slit:

P1140900.jpg

P1140900.jpg (112.29 KiB) Viewed 1741 times

SlitDIC:

P1140899.jpg

P1140899.jpg (129.43 KiB) Viewed 1741 times

P1140902.jpg

P1140902.jpg (114.43 KiB) Viewed 1741 times

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Re: Slit Interference Contrast

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#3

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by lightshape » Thu Jan 14, 2021 7:32 pm

For comparison, Nomarski DIC

P1140903.jpg

P1140903.jpg (156.38 KiB) Viewed 1734 times

P1140904.jpg

P1140904.jpg (136.56 KiB) Viewed 1734 times

P1140905.jpg

P1140905.jpg (129.1 KiB) Viewed 1734 times

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Re: Slit Interference Contrast

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#4

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by MicroBob » Thu Jan 14, 2021 8:21 pm

Hi,

that looks very promising!

Is your setup similar to the PZO DIC with slit condenser? PZO uses a stit aperture in the condenser and an analyser in an intermediate tube between microscope head and observation tube.

Did you see a dependency on the orientation of the diatoms?

Bob

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Re: Slit Interference Contrast

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#5

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by lightshape » Thu Jan 14, 2021 9:03 pm

Hi Bob,

the basic design has to be the same as with PZO, but my prism height is fixed.

I didn't focus on details like specimen orientation or perfect rendering yet.

And diatoms are not my favorite specimens for real DIC.

But they look quite nice with slitDIC and i thought they are well suited for a quick comparison and reproducible views.

Using slit aperture and polarizer on their own already greatly improve the contrast of the image.

No news..

Printing an adjustable slit now.

Stefan

dIY DIC

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#1

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by Sauerkraut » Sat Jun 08, 2019 5:12 pm

Has anyone had any luck with diy DIC? I found this link and tried out this method but it didn't really work as of yet:

http://www.microscopy-uk.org.uk/mag/ind ... iydic.html

I had fleeting 'just ok/kinda looked like DIC' results with a wedge shaped filter but could not repeat them with other pond water samples. I've also had difficulty getting reliable darkfield with black dots (tried lots of sizes) and am guessing that for some microscopes, it's better to just buy the corresponding darkfield condenser.

Heather

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Re: dIY DIC

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#2

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by PeteM » Sat Jun 08, 2019 7:21 pm

I've been experimenting, sometimes with pretty good results. My ultimate goal is to be able to take amazing pictures for the "single image science lessons" being developed for a kids' program. Too much else going on to adequately document progress so far, but I can make some comments.

1) If it's just reflected DIC you want, it's pretty easy and relatively affordable to buy used gear. And the prisms in an epi unit can provide a basis for further experimentation.

2) My take is that there are three limitations to achieving somewhat decent and affordable transmitted DIC results. First, is finding affordable DIC prisms. Even used, a complete set of prisms top (above the objective) and bottom (in the condenser) runs near $2000 for older gear (e.g. PZO, 1st generation Nikon, older Zeiss), maybe $3000 for slightly more popular gear (e.g. Olympus BH but not BH2), and $4000 up for more modern scopes (BH2, BX series, etc.). The cost is prohibitive for most hobbyists. So, I suspect what most DIY hobbyists have done is buy most any prism that shows up cheap, hoping it can be matched up in a system. Even at this level, you're looking at around $100-150 per prism and might want as many as eight (four top and bottom) prisms.

2) Second problem is that practically no prisms are marked with shear angles or even orientations and few objectives have an indication of where the prism (with some specified shear angle) should be located. So, barring optical testing equipment and greater knowledge of optics than I have, it's a trial and error process. If anyone can point me to a somewhat decipherable optical tract that could help with this, I'd be grateful.

3) Third problem is more mechanical - setting up rigs where one could fairly easily experiment with prism locations. They ideally want three degrees of freedom (rotational, lateral, up and down). That one is a bit easier for me, having been cursed/blessed with the "tool gene."

I've had decent results with these combinations:

1) PZO DIC condenser, re-oriented 45 degrees on a Leica DM series scope, fitted with Nikon 60mm infinity objectives, with Olympus epi prisms fitted to a DIC topside slider. Probably easier, though, to just look for a complete PZO system (though limited a bit by the older PZO objectives). There has been a glut of very cheap 20x infinity Nikon Apo objectives on Ebay -- and DIC results with this objective are very satisfying (at least to me).

2) Various Olympus stands with a proper top slider, with epi prisms removed and re-located as close as possible to the condenser diaphragm. If anyone wants to sell an Olympus condenser populated with Olympus prisms -- for just an arm OR a leg -- please let me know.

3) An actual and complete Nikon v2 DIC condenser and slider (but not holder) fitted to a makeshift holder. This works well with both Nikon top end finite and Olympus top end finite objectives. Olympus SPlan objectives are what they recommend for DIC and they seem to work pretty well. The Nikon and Olympus finite Apos I have also work well.

4) Olympus epi DIC prisms (sometimes affordable) fitted to Olympus SPlan objectives and a makeshift 1.25x polarizer holder up top, and those same type prisms removed and fitted to condenser apertures as close as possible to the iris. I modify condensers to fit a slider holding these prisms.

Sometimes there is banding evident. Sometimes the effect is best with a combination of oblique (prism shifted) and shear angle illumination. And sometimes it's very good. When time permits, I've got a batch of older Leica/Reichert epi prisms to try as well.

In general, my experience is that the cost of experimentation is about the same as biting the bullet and spending the money just once on a proper and complete DIC system. Still, I've enjoyed the experiment and in the end I expect to have half a dozen pretty decent (image-wise) DIC systems.

Someone wanting DIC for a clinical application would likely be crazy to head down this path -- you'd have even less idea of what you were seeing in terms of the false relief. But, someone wanting cool images might actually find greater control with DIC prisms that can be combined with oblique movements.

I realize folks would like photos and better descriptions, but I simply don't have time to make that a priority now. What I can say, is that it's possible -- if time consuming -- to cobble together a pretty decent (image wise) DIC system with just the prisms costing under $1K. But recognize it's also a bit like diving into a black hole :-).

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Re: dIY DIC

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#3

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by viktor j nilsson » Sat Jun 08, 2019 7:55 pm

A while ago I picked up a Nikon optiphot nosepiece that came with 4 epi DIC prisms: 5x, 10/40/100x (2pcs) and 20x prisms. Paid $180 for it. (It also came with 20x and 40x M plan objectives.) I've been experimenting a bit with these prisms on my Wild M20 stand. I still haven't optimized anything: I've simply placed one prism between the nosepiece and binocular head, and held one prism under the condenser (making sure they are aligned and at a 45 degree angle relative to two crossed polarizers. The biggest problem is probably that the top prism is l not at the rear focal plane of the objectives when placed this way, but I've still gotten at least somewhat useful 'true' DIC with 10x,20x and 40x Nikon CF Fluor objectives using some combinations of these prisms (must dig up my notes to remember which ones)..

I plan to post further updates on this whenever I get the time to work on it some more.

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Re: dIY DIC

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#4

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by 75RR » Sat Jun 08, 2019 8:03 pm

What Wim van Egmond refers to as DIY DIC is effectively finely tuned oblique. This takes a little practice but is well worth the extra effort.

Here are a couple of links. The first is to some van Egmond masks in pdf that forum member Rod Nabholz has kindly made avalilable. They are designed to be printed out on acetate film.

viewtopic.php?f=15&t=4499

The other link is to a post on the Gradient Universal Filter (which is also oblique lighting), which shows what can be achieved with it and how the filter is made.

http://www.photomacrography.net/forum/v ... hp?t=15142

Zeiss Standard WL (somewhat fashion challenged) & Wild M8

Olympus E-P2 (Micro Four Thirds Camera)

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Re: dIY DIC

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#5

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by MicroBob » Sat Jun 08, 2019 8:29 pm

Hi Heather,

these filter tricks work differently well with different microscopes. Also it is always necessary to do some fiddling to get the best image so repeatability or even quick repeatability is not really available. On the other hand side a real DIC setup is also difficult (and expensive!) to assemble and still a bit fiddly.

I think with some experience and a well arranged set of filters very nice results can be obtained.

Dark field can be obtained with dark field stops only for the lower power objectives, in some cases it still works with the 40:1 objective. The whole microscope has to be set up well centered for this to work well.

If it doesn't work right from the beginning I would start to optimize it just for the 10:1 objective. When this is managed I would try it with the other objectives.

There are interesting filter combinations: A light blue background combined with oblique for example. There are filter foil sample kits available for acceptable money. The addition of polarizers can offer interesting effects that can also be varied.

Bob

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Re: dIY DIC

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#6

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by billbillt » Sat Jun 08, 2019 8:49 pm

Sauerkraut wrote:Has anyone had any luck with diy DIC? I found this link and tried out this method but it didn't really work as of yet:

http://www.microscopy-uk.org.uk/mag/ind ... iydic.html

I had fleeting 'just ok/kinda looked like DIC' results with a wedge shaped filter but could not repeat them with other pond water samples. I've also had difficulty getting reliable darkfield with black dots (tried lots of sizes) and am guessing that for some microscopes, it's better to just buy the corresponding darkfield condenser.

Heather

"Hi Heather,

This method is not DIC, but a method of oblique illumination... DIC is much more complex than that...

Regards,

BillT

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Re: dIY DIC

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#7

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by zzffnn » Sat Jun 08, 2019 11:01 pm

DIY oblique gets difficult over 40x NA 0.65 and does not produce the same contrast DIC produces. My own (years of) test results showed that DIY oblique can provide decent visual 3D effects at high power, but such effects cannot be easily captured with camera.

So for me, if I were to pursue DIY DIC like how @PeteM did it, I would want at least 1-2 prism sets for high power objectives. DIY oblique or darkfield did well at equal or under NA 0.65 (so I would save money there, if budget is really tight).

@PeteM and @viktor j nilsson,

You both did great DIY work there. Please update the forum, when you have a chance.

I think when objective NA goes over 0.65, locating objective back focal plane precisely and maintaining tube length gets harder and is much more critical, for finite objectives at least.

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Re: dIY DIC

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#8

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by Sauerkraut » Sun Jun 09, 2019 3:01 am

Thanks to all for the detailed responses. Finely tuned oblique is much more realistic for me than acquiring and experimenting with prisms. At least for now.

I’m going to try those printable filters as a next step. And tinker more with dark field too.

Heather

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#9

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by zzffnn » Sun Jun 09, 2019 4:21 am

Here is the gradient oblique template that I made, which may be easier to print than the original: http://www.photomacrography.net/forum/v ... ght#173389

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Re: dIY DIC

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#10

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by MicroBob » Sun Jun 09, 2019 5:22 am

[quote="zzffnn"]DIY oblique gets difficult over 40x NA 0.65 and does not produce the same contrast DIC produces. My own (years of) test results showed that DIY oblique can provide decent visual 3D effects at high power, but such effects cannot be easily captured with camera.

So for me, if I were to pursue DIY DIC like how @PeteM did it, I would want at least 1-2 prism sets for high power objectives. DIY oblique or darkfield did well at equal or under NA 0.65 (so I would save money there, if budget is really tight).

Hi Fan,

thank you for sharing your experiences and an interesting approach! Probably the prices for DIC prisms for 100:1 objectives will skyrocket now! :mrgreen:

I can imagine that these DIY filter contrasting methods have more potential than it appears. When looking at great plancton images they are often taken with DIC. But DIC is commecially availabe (more or less) in a well designed setup. DIY contrast techniques usually consist of a heap of plastic film bits, cardboard and isolation tape of little permanence and appeal. So if one would build a nice set of holders and a box for them they would probably be used more - a nice project for a 3D-printer.

Bob

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Re: dIY DIC

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#11

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by Wes » Sun Jun 09, 2019 6:38 am

zzffnn wrote:So for me, if I were to pursue DIY DIC like how @PeteM did it, I would want at least 1-2 prism sets for high power objectives. DIY oblique or darkfield did well at equal or under NA 0.65 (so I would save money there, if budget is really tight).

I have only two DIC objective prisms, one for 16x/0,35 and one for 63x/1,4 lens. The 16x prism works very well with the 10x/0,32 Planapo (probably the matching NA helps) and reasonably well with 6,3x objectives. The 63x slider I use mostly with a 40x apo lens and while its quite delicate to set it properly it gives satisfactory DIC (but I wouldn't mind getting a dedicated 40x DIC slider in the future).

Zeiss Photomicroscope III BF/DF/Pol/Ph/DIC/FL/Jamin-Lebedeff

Youtube channel

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Re: dIY DIC

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#12

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by Sauerkraut » Sun Jun 09, 2019 2:17 pm

zzffnn wrote:Here is the gradient oblique template that I made, which may be easier to print than the original: http://www.photomacrography.net/forum/v ... ght#173389

Thank you for this link, zzffnn. I'll play with this idea too. The prism conversations are interesting but admittedly for me as a beginner, are way over my head.

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Re: dIY DIC

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#13

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by zzffnn » Sun Jun 09, 2019 3:15 pm

Wes,

Sorry to be so blunt. Your rotifer image came out great, so I agree that mismatched 16/0.35 slider worked well at 10/0.32.

Have you tested your 63x slider + 40x Apo on a small rotifer or its body part though?

I think paramecium is a comparatively easier subject for DIC, as it would look quite good under oblique (because paramecium are naturally textured, yet those textures are smooth / won't produce too much shadows under oblique; rotifer is a bit more difficult for oblique).

I tested my best oblique under 40/0.95 on a rotifer a few months ago. What I did not like included:

1) oblique produced too much shadows;

2) oblique 's 3D enhancement effect can be seen under visual eyepiece, but contrast is not great and my cameras Olympus E-M10 mk2 and E-M1 mk1 failed to capture such contrast well (lots of software enhancement was needed to even match visual view, camera-captured dynamic range was lacking; I know HDR can be used, but is not appropriate for moving subjects).

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Re: dIY DIC

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#14

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by zzffnn » Sun Jun 09, 2019 3:45 pm

Bob,

Forum member Saul at Photomacrography.net already 3D- printed filters (w/ holder inserted) for Olympus BH(2?) and Nikon Labophot/Optiphot and is probably working on others:

http://www.photomacrography.net/forum/v ... ht=#248468

DIY oblique should not be too difficult, even without 3D printer, for a DIY'er who is willing to try different approaches. Legos, opaque circles, Blutak and glue worked well for me.

I would love a good alternative than buying factory-matched DIC for high NA / high magnification, but I have not found it yet (which is why I am keenly interested in @PeteM 's and @viktor j nilsson's innovative work; I think @apochronaut is doing something related as well).

For me (and maybe some other microscopy enthusiasts), at NA 0.85 and above, oblique's potential is limited by its (sometimes excessive) shadow effects and lack of dynamic contrast, even though it does produce good textural (3D) enhancement. Such shadow effect also limits potential of high magnification darkfield. DIC can produce darkfield effect without much shadow or aperture reduction.

I came to this conclusion, for my own use, after years of experimenting with Leitz Heine, various DIY oblique set ups and oil darkfield condensers.

So I would like to obtain versatile DIC (probably PZO) for NA 0.85 and up for my short LOMO apos. I have not tried Reichert Polyphos or Zeiss pancratic condenser for oblique and darkfield, but I doubt they would produce qualitatively better imagery than the Leitz Heine that I tried (which is still not ideal for high magnification photography). I may try The Zeiss pancratic condenser if I can find one for cheap, but otherwise I would just save up for DIC. And when I do buy DIC, I will sell my Leitz Heine and most of my darkfield condensers. I may have to change to Olympus BH(2?) stands though (from my Nikon Optiphot teaching rig), as I heard Oly has some head compatibility with PZO, but such a transition + modifications will cost me quite a bit

:cry:

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Re: dIY DIC

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#15

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by MicroBob » Sun Jun 09, 2019 7:10 pm

Hi Fan,

I have just assembled a PZO DIC set consisting of revolver condenser and MPI-3 (?) head. For a while now I am working on my office/lab room and work is not yet finished, most things are covered and not available. So I only had a quick try with the set and a 1960s cream white PZO MB 30 with some Vickers Microplan objectives and a half working LED. My first test looked promising so far.

As far as I could read the PZO DIC is comparatively adaptable to different setups. In one forum post I read that the member was not fully convinced of the optical quality of the PZO DIC, but this member got his high level of knowledge by being a Zeiss employee. ;)

My two components were bought separately for together about 380€ which is a lot of money for me, but not much for a working DIC setup (if it works as intended, that is). I'm looking forward to diving into this and ther is just one bay window to finish until I'm ready.

Bob

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Re: dIY DIC

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#16

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by PeteM » Sun Jun 09, 2019 7:59 pm

zzffnn wrote:. . . I may have to change to Olympus BH(2?) stands though (from my Nikon Optiphot teaching rig), as I heard Oly has some head compatibility with PZO, but such a transition + modifications will cost me quite a bit

:cry:

Fan,

I've had pretty good luck swapping heads on microscopes, by acquiring and re-machining an intermediate adapter. I've also used epi illumination pieces (cutting off the illumination tube) for this purpose.

For finite scopes like the Nikon and Olympus this will usually be a 1.25x with a lot for a polarizer (and sometimes where I also add a DIC prism). You basically keep the dovetail that matches what you want to do but re-machine or re-make the other dovetail to mate it up.

For infinite scopes, just an open intermediate tube with whatever polarizer and/or DIC unit you want is usually all that's needed.

I've mated BHS stands to BX infinity optics, used an Olympus DIC slider on an Optiphot, put Reichert heads on a mis-matched Leica, have a Nikon DIC slider on a BHS, and so on. The Optiphot is a terrific microscope and I'd think you could adapt it. I will say that the Olympus intermediate optics seem a bit easier to come by and have plenty of room to fit most anything you'd want.

Most any metal lathe will cut these dovetails, but you need a very acute angle in the tool to reach into the dovetail.

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Re: dIY DIC

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#17

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by Hobbyst46 » Sun Jun 09, 2019 8:20 pm

Sauerkraut wrote:Has anyone had any luck with diy DIC? I found this link and tried out this method but it didn't really work as of yet:

http://www.microscopy-uk.org.uk/mag/ind ... iydic.html

I had fleeting 'just ok/kinda looked like DIC' results with a wedge shaped filter but could not repeat them with other pond water samples. I've also had difficulty getting reliable darkfield with black dots (tried lots of sizes) and am guessing that for some microscopes, it's better to just buy the corresponding darkfield condenser.

Heather

I do not know which microscope you have, here is a link to an eBay darkfield condenser. It is Carl Zeiss Jena, but perhaps it will fit ?

https://www.ebay.com/itm/Carl-Zeiss-Kar ... 3733578851

(would have bought it myself but he/she only ships to the USA). Of course, I suggest to inquirie the seller about the condition of the optics, delamination, internal mirrors etc.

Here is another eBay item from a seller "near" you - the price is low, I wonder if it is real...perhaps worthy of checking... I have very little experience with DIC so cannot be specific.

https://www.ebay.com/itm/E-LEITZ-LABORL ... 3806059270

Note: I am not related to the above sellers in any way.

Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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Re: dIY DIC

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#18

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by 75RR » Mon Jun 10, 2019 3:24 am

Note: I am not related to the above sellers in any way.

It would make more sense if you were! ;) Can't see any component that would indicate it has DIC - on top of which the no return policy is not especially helpful.

Zeiss Standard WL (somewhat fashion challenged) & Wild M8

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apochronaut

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Re: dIY DIC

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#19

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by apochronaut » Mon Jun 10, 2019 10:44 am

Sauerkraut wrote:Has anyone had any luck with diy DIC? I found this link and tried out this method but it didn't really work as of yet:

http://www.microscopy-uk.org.uk/mag/ind ... iydic.html

I had fleeting 'just ok/kinda looked like DIC' results with a wedge shaped filter but could not repeat them with other pond water samples. I've also had difficulty getting reliable darkfield with black dots (tried lots of sizes) and am guessing that for some microscopes, it's better to just buy the corresponding darkfield condenser.

Heather

Heather.

If you start looking for PZO DIC, you will find that there are several parts to the system, some of which don't look like they belong there; at least when you compare PZO to other DIC systems. PZO never referred to their system as DIC. The manual for the system is titled Biolar Interference Microscope. There were other interference microscope systems and condensers in the 50's and the PZO system seems to be a bit of a composite. It includes a rotating condenser housing with 4 individual prisms but nowhere does the manual indicate whether the peisms are Wollaston, Nomarski or other. The manual provides instructions for 5 different methods to accomplish interference microscopy, some qualitative and some quantitative.

Another different condenser component in the PZO kit is a variable slit condenser, that is somewhat similar to using masks of various shapes and yields results not too different from Hoffman Modulation, which is a modified slit condenser system. The PZO slit condenser can sometimes by purchased separately and should easily be adaptable to other microscopes. It has a sleeve type mounting of 40mm and in it's complete form also includes a rotating polarizer below, that slides under on a dovetail. Both it and the above prism type condenser are referred to as interference condensers.

Occasionally on the used market, you also see a similar condenser to the PZO ; the Goerz 3-D condenser. The Goerz condenser also includes the possibility of combining a relief image created through a slit condenser but in this case the original set also included 2 darkfield caps. A few people use one to effect. Here is a forum thread populated with some nice results.

http://www.photomacrography.net/forum/v ... 2646add153

Last edited by apochronaut on Mon Jun 10, 2019 1:53 pm, edited 1 time in total.

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Re: dIY DIC

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#20

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by Wes » Mon Jun 10, 2019 1:43 pm

zzffnn wrote:Wes,

Sorry to be so blunt. Your rotifer image came out great, so I agree that mismatched 16/0.35 slider worked well at 10/0.32.

Have you tested your 63x slider + 40x Apo on a small rotifer or its body part though?

I think paramecium is a comparatively easier subject for DIC, as it would look quite good under oblique (because paramecium are naturally textured, yet those textures are smooth / won't produce too much shadows under oblique; rotifer is a bit more difficult for oblique).

I tested my best oblique under 40/0.95 on a rotifer a few months ago. What I did not like included:

1) oblique produced too much shadows;

2) oblique 's 3D enhancement effect can be seen under visual eyepiece, but contrast is not great and my cameras Olympus E-M10 mk2 and E-M1 mk1 failed to capture such contrast well (lots of software enhancement was needed to even match visual view, camera-captured dynamic range was lacking; I know HDR can be used, but is not appropriate for moving subjects).

While I can't recall how a rotifer looks like I've looked into yeast, nematodes, desmids, diatoms, intracellular movement in algae, squished fruit flies and it looks very nice (you can see fine intracellular details). One problem I see is that unlike matched components you do get a light intensity gradient which could be fixed with an exposure counter gradient later in image processing (works very well I only figured it out yesterday and you need RAW images). Now getting decent contrast requires fiddling with the coverslip correction collar, recombination prism lateral displacement (it works better when flipped upside down), condenser aperture and height. I suspect the dedicated 40x prism would give stronger contrast but this works reasonably well.

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Re: dIY DIC

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#21

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by Sauerkraut » Mon Jun 10, 2019 3:57 pm

apochronaut wrote:If you start looking for PZO DIC, you will find that there are several parts to the system, some of which don't look like they belong there; at least when you compare PZO to other DIC systems. PZO never referred to their system as DIC. The manual for the system is titled Biolar Interference Microscope. There were other interference microscope systems and condensers in the 50's and the PZO system seems to be a bit of a composite. It includes a rotating condenser housing with 4 individual prisms but nowhere does the manual indicate whether the peisms are Wollaston, Nomarski or other. The manual provides instructions for 5 different methods to accomplish interference microscopy, some qualitative and some quantitative.

Another different condenser component in the PZO kit is a variable slit condenser, that is somewhat similar to using masks of various shapes and yields results not too different from Hoffman Modulation, which is a modified slit condenser system. The PZO slit condenser can sometimes by purchased separately and should easily be adaptable to other microscopes. It has a sleeve type mounting of 40mm and in it's complete form also includes a rotating polarizer below, that slides under on a dovetail. Both it and the above prism type condenser are referred to as interference condensers.

Occasionally on the used market, you also see a similar condenser to the PZO ; the Goerz 3-D condenser. The Goerz condenser also includes the possibility of combining a relief image created through a slit condenser but in this case the original set also included 2 darkfield caps. A few people use one to effect. Here is a forum thread populated with some nice results.

http://www.photomacrography.net/forum/v ... 2646add153

Thank you for this information. Very useful.

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Re: dIY DIC

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#22

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by MicroBob » Mon Jun 10, 2019 6:22 pm

Hi together,

concerning PZO DIC: There are upper DIC units named MPI-2, MPI-3 (the one I have) and MPI-5 (looks different than the two before). The revolver condenser seems to be always KPI-2. In the internet I found a description of the newest system for the Biolar, with MPI-5, KPI-2 and additional slit condenser.

Does someone have information what the difference between these three upper DIC units is? Does someone have a manual for the system with my MPI-3 head?

Bob

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Re: dIY DIC

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#23

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by Sauerkraut » Mon Jun 10, 2019 6:32 pm

75RR wrote:

Note: I am not related to the above sellers in any way.

It would make more sense if you were! ;) Can't see any component that would indicate it has DIC - on top of which the no return policy is not especially helpful.

Something like this looks better but I'm not well versed on the used market of older scopes and their technology:

https://www.ebay.com/itm/LEITZ-microsco ... SwvmxbcK2p

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Re: dIY DIC

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#24

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by apochronaut » Mon Jun 10, 2019 11:10 pm

I had a bit of an email conversation with that seller regarding another plasDIC system he was selling. It , like the older Leitz in this link was a retrofit and a kind of crude one at that. There was a sticker that said DIC on the slider and it was cockeyed. There was no polarizer. He didn't answer my last question which was: is there a polarizer under the condenser?

So in this case, questions still stand out, not to mention that if the pictures of images he is showing on the computer screen are representative of the quality that the system can do, then I would have to say the retrofit probably needs several years of further development.

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Re: dIY DIC

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#25

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by zzffnn » Tue Jun 11, 2019 3:01 pm

Thank you very much @PeteM. You made a great point, which would save me (and likely other DIY microscopists) quite a bit of money! Let me know how I can return your favor or buy you some (virtual) beer.

The Nikon epi attachment that I have adds 50mm to optical tube length and does not have a pair of lenses to cancel out added tube length (because some Nikon epi objectives use 210mm tube length, as you know). It does offer space to add a prism and a polarizer, along with possibility of changing dovetail.

I do have a Nikon teaching arm attachment that adds about 40mm tube length, which does seem to have a pair of (tube length) correcting lenses inside.

So for such head swapping (which is the darkest magic in microscopy wizard land, other than DIY DIC :mrgreen: ), I need a pair of correcting lenses from some other cheaper parts (recommendations? Lenses of any brand would work as long as they cancel out the added tube Length). That is because my preferred objectives use 160mm tube length.

I think condenser adaptation may be accomplished without machine work. I have done quite a few before.

I hope this discussion can also help others. Complete Nikon scopes seem cheaper and easier to find than Olympus / Leitz / Zeiss in US nowadays.

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abednego1995

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Re: dIY DIC

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#26

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by abednego1995 » Wed Jun 12, 2019 6:35 am

apochronaut wrote:I had a bit of an email conversation with that seller regarding another plasDIC system he was selling. It , like the older Leitz in this link was a retrofit and a kind of crude one at that. There was a sticker that said DIC on the slider and it was cockeyed. There was no polarizer. He didn't answer my last question which was: is there a polarizer under the condenser?

So in this case, questions still stand out, not to mention that if the pictures of images he is showing on the computer screen are representative of the quality that the system can do, then I would have to say the retrofit probably needs several years of further development.

The Zeiss plasDIC system is a rather "basic" interference system. It beautifully represents what interference between different wavefronts do in a microscope system.

The only catch with the PlasDIC is that it can't be used with high NA objectives due to the slit mask in the condenser aperture plane.

Since PlasDIC is intended for observing objects in birefringent containers, the polarizer is set after the container.

However, the lower polarizer can be anywhere before the Nomarski prism in the light train as long as you don't use birefringent elements in between.

If you already have a Nomarski DIC system, pseudo-PlasDIC can be demonstrated by setting up DIC normally and removing the condenser prism while closing down the condenser iris or making a slit aperture mask that has its long side perpendicular to the objective prism shear direction.

There's a paper explaining how it works.

https://www.osapublishing.org/oe/abstra ... 6-24-19462

PlasDIC.png

PlasDIC.png (179 KiB) Viewed 15123 times

Theoretically, as long as you stick with low NA, I consider this to be the cheapest DIY DIC option there is.

(I also believe you can obtain DIC in this fashion with metallurgical epi-DIC kits in diascopic mode using a polarizer under the condenser)

Due to the very limited NA, prism shear amount is very forgiving (using too small values would decrease the contrast generated though). Plus the back focal plane of low mag objectives is often outside the objective, which is very helpful when aligning mismatched prisms to it.

However, if you just need to observe transparent objects, phase contrast and Hoffman Modulation Contrast is sufficient (and is great with any NA).

So.... the bottom point I guess, is if you want great DIC images at any NA and with perfect pupil compensation (that's why Nomarski DIC needs 2 prisms), get a complete set in the beginning.

If you're the experimenter who cares more about optics and is curious of the physics, DIY DIC is your path (not always pleasant, but rewarding).

Cheers,

John

Last edited by abednego1995 on Wed Jun 12, 2019 7:01 am, edited 1 time in total.

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Re: dIY DIC

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#27

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by MichaelG. » Wed Jun 12, 2019 7:01 am

Thanks for that, John ... Very helpful.

MichaelG.

Too many 'projects'

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Re: dIY DIC

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#28

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by viktor j nilsson » Wed Jun 12, 2019 10:21 am

Good point, John. I've been wondering why so few people talk about DIC using a slit condenser. If I've understood it correctly, the plasDIC system is basically a rebranding of the techniques that were already fully described in the very earliest DIY literature. (And implemented, for example, in the. PZO slit condenser).

Making a DIY slit condenser would be super simple - my DIY Hoffmann condenser works great, I just cut a slit in an old credit card that fits under my condenser.

I've only found a few pictures online that have been made with a slit condenser/plasDIC, and most of them are from medical research setups that haven't really been done with the aim of getting 'nice' pictures. I'm keen to experiment to see how good it can get.

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Re: dIY DIC

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#29

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by abednego1995 » Wed Jun 12, 2019 10:43 am

Yup, Viktor, I think your getting that effect in your beforementioned setup.

As you mention, in it's most primitive form DIC employs a pinhole condenser.

PlasDIC improves on it by using a rectangular slit allowing somewhat higher NA information to pass through (though direction limited).

So little information and images from PlasDIC is probably due to it's limited use in in-vitro fertilization and micro-injection techniques where that halo from phase contrast is distracting.

(IMO, HMC is good enough for those techniques sans halo, so PlasDIC is something uber-rich clinics and labs might buy in the first place.)

Cheers,

John

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apochronaut

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Re: dIY DIC

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#30

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by apochronaut » Wed Jun 12, 2019 4:15 pm

viktor j nilsson wrote:Good point, John. I've been wondering why so few people talk about DIC using a slit condenser. If I've understood it correctly, the plasDIC system is basically a rebranding of the techniques that were already fully described in the very earliest DIY literature. (And implemented, for example, in the. PZO slit condenser).

Making a DIY slit condenser would be super simple - my DIY Hoffmann condenser works great, I just cut a slit in an old credit card that fits under my condenser.

I've only found a few pictures online that have been made with a slit condenser/plasDIC, and most of them are from medical research setups that haven't really been done with the aim of getting 'nice' pictures. I'm keen to experiment to see how good it can get.

The Goerz condenser is also an implementation of the slit condenser interference system. I have never encountered a manual for the Goerz condenser but it also has DF capability. The manual for the PZO polarizing interference microscope shows 3 separate interference methods incorporating their slit condenser; a differential method, a uniform field method with high image shearing and a fringe method.

Re: dIY DIC

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#31

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by Hugh » Fri Dec 20, 2019 12:17 am

Hi - just invested in a Nikon Eclipse 55i - which was supposed to be DIC (the objectives have DIC marked on them - but appear to be completely normal objectives (am I missing something?) - there is a polarizer and an analyser (in the headstage) - nothing resembling prisms.

What is missing - there appears to be a dearth of information on this. Also - looking for a x100 (infinity optics) objective for this. Maybe contact me

hugh@austrop.org.au

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Re: dIY DIC

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#32

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by wporter » Fri Dec 20, 2019 12:39 am

The objectives marked 'DIC' don't have internal prisms, but rather have high-quality strain-free & occlusion-free optical glass. There is still a need for a prism external to and above the objective, and one below the objective.

See the below page for a nice color graphic (Fig. 1) of a DIC optical system showing the components.

Quote:

"Objectives designed for differential interference contrast must be free of strain or birefringent occlusions that depolarize light and lead to image degradation. In the past, microscopists were limited to strain-free achromat and fluorite objectives intended for observations in polarized light, but modern objectives having higher correction factors can now be employed for DIC microscopy. Termed universal objectives, these advanced lens systems can often be used for combined DIC, fluorescence, phase contrast, and brightfield microscopy without having to change objectives. In addition, newer apochromatic objectives have been designed that are sufficiently strain free to enable their use in polarized light and differential interference contrast observation, dramatically improving the image quality and resolution at higher magnifications."

from https://www.olympus-lifescience.com/en/ ... iguration/

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Re: dIY DIC

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#33

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by Hugh » Fri Dec 20, 2019 2:00 am

Thanks for that

Unfortunately my server won't display the link - seems it has security issues.. (?!)

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Re: dIY DIC

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#34

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by RobBerdan » Mon Jan 20, 2020 5:39 am

I have DIC, Hoffman and I used oblique illumination which the article refers to. I believe the author has now purchased DIC. DIC is unfortanetly very expensive to make. A number of researchers have been working on developing software that is supposed to simulate DIC or Phase contrast, but none has answered my emails. Still I believe it will come in the future.

Oblique illumination can easily be created by simply moving your filter holder to partially obscure the incoming light. It might work better with certain objectives. Hoffman modulation - simulates DIC but only in Black and white and is useful because most forms of DIC can't be used with plastic tissue culture dishes. Zeiss offers a version of DIC for plastic dishes, but it is inferior to real DIC.

Below I have attached 3 images 1) Hoffman Modulation contrast 2) Oblique pseudo DIC and 3) Real DIC

ATTACHMENTS

DSC_0695.jpg

DSC_0695.jpg (165.99 KiB) Viewed 5557 times

rotifer_DSC_0210.jpg

rotifer_DSC_0210.jpg (126.84 KiB) Viewed 5557 times

38.jpg

38.jpg (145.71 KiB) Viewed 5557 times

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Re: dIY DIC

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#35

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by rmb » Sat Apr 18, 2020 12:39 pm

I have a method called varable amplitude contrast (VAC) working and it compares very, very favourably with DIC although it works in a different way. It involves 3 pieces of polarised film. 2 are arranged to make a stops for each objective (this is the hardest part to make) which are fitted into a phase condenser so they are in the right focal plane. The other rotates over the light well. No special objectives are needed. It also gives superior dark field

The method was described in an issue of the balsam post a few years back.

I dont know why it isnt used by more people

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Re: dIY DIC

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#36

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by 75RR » Sat Apr 18, 2020 12:54 pm

The method was described in an issue of the balsam post a few years back.

I dont know why it isnt used by more people

Can you provide a link to it?

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Re: dIY DIC

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#37

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by Roldorf » Sat Apr 18, 2020 2:51 pm

For Those looking for a link to the Balsam Post and the above Variable contrast method VAC see here for some images:-

https://postalmicroscopicalsociety.gith ... trast.html

For an explanation of the method see this post from the old Microbehunter forum:-

http://www.microbehunter.com/forum/spec ... hod-vac-2/

It seems only one of the suppliers of the polarizing film still have it available:

http://www.greenweld.co.uk/acatalog/Pol ... _Film.html

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Re: dIY DIC

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#38

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by 75RR » Sat Apr 18, 2020 3:28 pm

Thanks Roldorf - good sleuthing!

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Re: dIY DIC

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#39

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by Roldorf » Sun Apr 19, 2020 8:57 am

Nahh, good search engine:- www.startpage.com billed as (The world's most private search engine) instead of using google. I use this as my preferred search engine.

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Re: dIY DIC

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#40

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by nelson » Wed Apr 21, 2021 5:26 pm

Hello Everyone,

I've been lurking in the shadows here for some time - first visit many years ago and now back again.

I know this is a fairly old thread, but I daringly open it up again as I just noted some quite new information on the subject and would like to share it.

There's an article published last year titled "Differential interference contrast microscopy with adjustable plastic Sanderson prisms" that may reveal a plausible path for DYI DIC. It's available here (for a fee): https://www.osapublishing.org/ao/abstra ... 59-11-3404

The actual prism and its initial construction is described here (free for the taking): https://authors.library.caltech.edu/6948/1/SANrsi05.pdf

The PDF is quite mathematically oriented, but also shows actual results as well as very good images of the prism and its construction.

Hope this sparks som new ideas - enjoy!

:)

Cheers,

Nelson

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Re: dIY DIC

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#41

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by Saul » Wed Apr 21, 2021 6:26 pm

nelson wrote: ↑

Wed Apr 21, 2021 5:26 pm

...There's an article published last year titled "Differential interference contrast microscopy with adjustable plastic Sanderson prisms" that may reveal a plausible path for DYI DIC. It's available here (for a fee): https://www.osapublishing.org/ao/abstra ... 59-11-3404

The actual prism and its initial construction is described here (free for the taking): https://authors.library.caltech.edu/6948/1/SANrsi05.pdf

The PDF is quite mathematically oriented, but also shows actual results as well as very good images of the prism and its construction...

https://www.photomacrography.net/forum/ ... 70#p269570

https://www.microbehunter.com/microscop ... =Sanderson

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Re: dIY DIC

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#42

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by nelson » Wed Apr 21, 2021 7:19 pm

Saul wrote: ↑

Wed Apr 21, 2021 6:26 pm

nelson wrote: ↑

Wed Apr 21, 2021 5:26 pm

...There's an article published last year titled "Differential interference contrast microscopy with adjustable plastic Sanderson prisms" that may reveal a plausible path for DYI DIC. It's available here (for a fee): https://www.osapublishing.org/ao/abstra ... 59-11-3404

The actual prism and its initial construction is described here (free for the taking): https://authors.library.caltech.edu/6948/1/SANrsi05.pdf

The PDF is quite mathematically oriented, but also shows actual results as well as very good images of the prism and its construction...

https://www.photomacrography.net/forum/ ... 70#p269570

https://www.microbehunter.com/microscop ... =Sanderson

Now... That's plain beautiful! Thanks!

I did look around, but obviously I didn't do it well enough.

I will carefully have a look att your work with this before I start asking all the questions lining up.

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Re: dIY DIC

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#43

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by jmp » Wed Apr 21, 2021 9:49 pm

...There's an article published last year titled "Differential interference contrast microscopy with adjustable plastic Sanderson prisms" that may reveal a plausible path for DYI DIC. It's available here (for a fee): https://www.osapublishing.org/ao/abstra ... 59-11-3404

That paper was mentioned in the 2021 meeting reports from the Quekett Microscopical Club and the pdf is visible here, in case someone can't get through the article paywall.

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nelson

Posts: 3

Joined: Wed Apr 21, 2021 5:15 pm

Re: dIY DIC

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#44

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by nelson » Wed Apr 21, 2021 10:20 pm

Thank you very much!

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BramHuntingNematodes

Posts: 1415

Joined: Tue Jan 21, 2020 1:29 am

Location: Georgia, USA

Re: dIY DIC

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#45

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by BramHuntingNematodes » Thu Apr 22, 2021 2:09 am

Holy smokes do you see how that works? You bend the prism!

1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

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LouiseScot

Posts: 1001

Joined: Tue Jul 07, 2020 1:51 pm

Location: Scotland

Re: dIY DIC

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#46

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by LouiseScot » Fri Apr 23, 2021 1:11 pm

Hi all

The 'Sanderson Prism' idea looks interesting and relatively easy to implement. In the paper their lens 2 is 80mm diameter! Not sure why that should be other than it just happened to be a lens they had easy access to. Else maybe it was to go with the larger 'open frame' prism holder? Surely a duplicate of the condenser prism holder would do? Lens 1 is a more standard 25.4mm (1").

I think I might have a go at putting together one of these DIC-type setups :) . They don't give exact details of the working of the condenser prism holder but I guess it just follows the same principles as the frame prism holder so shouldn't be too difficult to hack. I assume they just put the frame holder together based on Sanderson's paper/design and adapted it for the DIC.

Anyone else fancy having a go?

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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jmp

Posts: 66

Joined: Sun Feb 16, 2020 2:07 am

Location: Texas

Re: dIY DIC

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#47

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by jmp » Fri Apr 23, 2021 6:02 pm

Anyone else fancy having a go?

Yes. I have an inverted microscope that provides easy slider access to the condenser and to the back focal plane of the objective. I have the original phase sliders and also a condenser silt slider (and polarizer). The slit slider is used in conjunction with a wolaston prism slider for 10x and 20x 'PlasDIC' (but I don't have it). This setup was useful to tests 3D printed sliders that I built to play with 'variable asymmetric contrast' (VAC2), which give a really nice oblique and darkfield contrast for low power. It should be relatively easy to design and 3D print sliders to hold Sanderson Prisms (basically a polycarbonate bar if I'm reading this correctly) and screws to adjust the lateral stress on them. I already ordered a small piece of polycarbonate from ebay ($10 or so), similar to the one described in one of the papers mentioned above. Would be fun to play with this... another little project to add to an already long list...

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LouiseScot

Posts: 1001

Joined: Tue Jul 07, 2020 1:51 pm

Location: Scotland

Re: dIY DIC

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#48

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by LouiseScot » Fri Apr 23, 2021 7:17 pm

jmp wrote: ↑

Fri Apr 23, 2021 6:02 pm

Anyone else fancy having a go?

Yes. I have an inverted microscope that provides easy slider access to the condenser and to the back focal plane of the objective. I have the original phase sliders and also a condenser silt slider (and polarizer). The slit slider is used in conjunction with a wolaston prism slider for 10x and 20x 'PlasDIC' (but I don't have it). This setup was useful to tests 3D printed sliders that I built to play with 'variable asymmetric contrast' (VAC2), which give a really nice oblique and darkfield contrast for low power. It should be relatively easy to design and 3D print sliders to hold Sanderson Prisms (basically a polycarbonate bar if I'm reading this correctly) and screws to adjust the lateral stress on them. I already ordered a small piece of polycarbonate from ebay ($10 or so), similar to the one described in one of the papers mentioned above. Would be fun to play with this... another little project to add to an already long list...

Oh good! Maybe we can compare notes. I've ordered some 3mm polycarbonate sheet off Ebay (can't get 3/32" here!). I'll have a go at designing a holder similar to the condenser one in the paper. It's a pity the authors didn't show the inner workings of their one but I figure it must be similar, in principle, to the larger open frame.

Louise

A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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Greg Howald

Posts: 1117

Joined: Tue Oct 20, 2020 6:44 am

Re: dIY DIC

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#49

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by Greg Howald » Sat Apr 24, 2021 10:08 am

All I did was download the image of the filter being used, adjust the size for my scope and cut it out of black card stock. Upon first use I was immediately impressed. I did a little tweaking with it and it works really well. I didn't look at any science behind it. I just applied the knowledge. Thanks for this. It is appreciated.

Greg