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Polyvar DIC
Posted: Wed Jan 25, 2023 7:56 am
by WaterGoblin
Hello, I saw a video of a Polyvar being used for epi-dic, but I was wondering, can it be used for transmitted light DIC? does it have DIC prisms in the condenser or does it just have 1 nomarski prism over the objectives
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https://www.olx.ua/d/uk/obyavlenie/mkro ... derIndex=0)
Re: Polyvar DIC
Posted: Wed Jan 25, 2023 10:31 am
by blekenbleu
WaterGoblin wrote: ↑Wed Jan 25, 2023 7:56 am
can it be used for transmitted light DIC?
Some were so equipped; many were EPI only.
Search is your friend; I use Google, adding quoted key works, e.g.:
Code: Select all
site:www.microbehunter.com/microscopy-forum/ "polyvar" "dic"
Re: Polyvar DIC
Posted: Wed Jan 25, 2023 3:24 pm
by apochronaut
Most Polyvars sold were used in the electronics industries and were epi microscopes. They have larger diameter infinity objectives, 28mm thread I think and use a larger nosepiece.
Biological Polyvars are much fewer and use infinity 45MM R.M.S. objectives. The better corrected objectives are getting scarce. Planachros not so much.
There might be decent compatability between Polyvar objectives and other infinity corrected objectives but it would likely require an eyepiece swap in order to correct or compensate for a bit of lateral ca. Reichert objectives are well corrected. I have used Nikon format NIS objectives and Reichert objectives with the same eyepiece. Olympus objectives aren't perfect . Never tried Meiji. Nor Zeiss or Leica for that matter but mounting size could be a problem.
Re: Polyvar DIC
Posted: Mon Jan 30, 2023 12:56 am
by wabutter
The short answer is yes, DIC is possible with the Polyvar. I have two universal condensers with prism and phase rings for the Polyvar. I also have a couple of objective for this microscope. I may also have a Polyvar biological nosepiece. Yes, it only used one objective prism for all magnifications. The prism had two knobs for adjusting the height as well as the lateral position of the prism relative to back aperture.
One thing to keep in mind for the Polyvar is that each objective was hand fitted to the nosepiece at the factory. This permitted an unparalleled parfocality and parcentration from one objective to the next. Unlike most objective nosepeices, if you wanted to check centriicity, you needed to start at the highest mag and work down. On a properly outfitted Polyvar, one could start with the 2.5x objective, place an object in the middle of the field. and work you way up to the 100x and the object of interest would still be in the center of the field.
Re: Polyvar DIC
Posted: Thu Feb 02, 2023 3:13 am
by JWW
Sure wish I had a complete Biological Polyvar. Even more so, I would love to have the control box for my Polyvar SC or MET to operate the motorized turret.
-JW:
Re: Polyvar DIC
Posted: Fri Apr 07, 2023 11:25 am
by Rorschach
wabutter wrote: ↑Mon Jan 30, 2023 12:56 am
The short answer is yes, DIC is possible with the Polyvar. I have two universal condensers with prism and phase rings for the Polyvar. I also have a couple of objective for this microscope. I may also have a Polyvar biological nosepiece. Yes, it only used one objective prism for all magnifications. The prism had two knobs for adjusting the height as well as the lateral position of the prism relative to back aperture.
One thing to keep in mind for the Polyvar is that each objective was hand fitted to the nosepiece at the factory. This permitted an unparalleled parfocality and parcentration from one objective to the next. Unlike most objective nosepeices, if you wanted to check centriicity, you needed to start at the highest mag and work down. On a properly outfitted Polyvar, one could start with the 2.5x objective, place an object in the middle of the field. and work you way up to the 100x and the object of interest would still be in the center of the field.
Interesting info about Polyvar objectives being hand fitted to the turret at the factory. Quite amazing and a thing of past eras.
By the way, would you happen to have the slider/compensator for Polyvar EPI DIC? Or surplus parts/accessories?
Re: Polyvar DIC
Posted: Mon May 01, 2023 12:35 am
by wabutter
I do have a DIC slider, but I am not sure if it is for the Polyvar or the MeF4
Re: Polyvar DIC
Posted: Mon May 01, 2023 4:34 am
by Rorschach
wabutter wrote: ↑Mon May 01, 2023 12:35 am
I do have a DIC slider, but I am not sure if it is for the Polyvar or the MeF4
Interesting. Do you have photos of it? I am not entirely sure but I think it's the same slider that is used also for polarization (with the appropriate cube installed).
Re: Polyvar DIC
Posted: Mon May 01, 2023 7:11 am
by Rorschach
Rorschach wrote: ↑Mon May 01, 2023 4:34 am
wabutter wrote: ↑Mon May 01, 2023 12:35 am
I do have a DIC slider, but I am not sure if it is for the Polyvar or the MeF4
Interesting. Do you have photos of it? I am not entirely sure but I think it's the same slider that is used also for polarization (with the appropriate cube installed).
In the attached images, I have delineated the various sliders and compensators that I am missing for sure. The only slider that I do have is the one for transmitted light DIC.
If my German skills serve me, this one is the DIC slider for reflected light:
- Polyvar_reflected_light_DIC_slider.jpg (140.76 KiB) Viewed 2776 times
And all these three are various sliders and compensators for reflected light polarization:
- Polyvar_reflected_light_polarization_sliders_and_comparators.jpg (119.7 KiB) Viewed 2776 times
As to the function of each of these three polarization sliders, I have no idea, being a pretty complete beginner in the world of contrast techniques, especially when it comes to these "traditional light microscopes". Of them, I only know BF transmitted, but know a lot more of stereo microscopy. In the latter, I have regularly used transmitted BF and especially DF, transmitted polarized, and of course reflected light at various angles. For my stereo setup, I am building a Rottermann contrast base which is now lacking only one adapter, having recently received the blueprints for it from the finnish Leica distributor. So in summary, the Polyvar and it's myriad lighting and contrast techniques are going to be a source of learning experiences for me! Starting with trying to figure out which bits and bobs are going to be needed for exactly which use and technique.
Re: Polyvar DIC
Posted: Mon May 01, 2023 11:17 pm
by wabutter
I took a closer look at the DIC slider and I am fairly certain it is for an MeF3/4.