Hoffman Modulation Contrast (HMC) for Leitz Orthoplan?

[albertr]

Hello,

Does anyone have experience in using Hoffman Modulation Contrast on Leitz Orthoplan line? They seem to pop up on ebay from time to time.... How does it compare to Smith DIC?

Thanks!
-albertr

[Rorschach]

I fully realize that am resurrecting a very old thread but I think the topic warrants it! Is it really so, that nobody has tried to implement Hoffman Modulation contrast for the Leitz Orthoplan?

It would make sense, as Hoffman Modulation apparently can yield a kind of a similar contrast enhancement as DIC can. Perhaps not quite as good as DIC but still very useful? In light of the notorious difficulties in finding (and higher prices) of the Leitz DIC systems (especially for the Orthoplan), it seems that this avenue is very worthwhile?

This is a real 'asking for a friend' scenario as I am really doing that, trying to help a friend get the most out of her Orthoplan, on a limited budget.

[Pau]

In a similar way as Phase Contrast, HMC needs dedicated objectives with the modulation plate built in* (and the matched HMC plate at the condenser). Do you have such objectives?

Oblique illumination techniques can deliver DIC like relief contrast with normal objectives, there are many threads and posts on this topic at our forum and elsewhere.

*With some exceptions like the Leica IMC system for modern inverted microscopes

[Rorschach]

Pau, thanks for the clarification. It seems I went astray by reading exactly those Leica and other texts where normal objectives were used. No, neither I or her have special Hoffman objectives.

Therefore, it seems that oblique illumination is the avenue of exploration. I have read that this method induces quite a bit of chromatic aberrations but I do not know whether that also depends on the presence/absence of color corrections in the objectives and the condenser or not. Also remember reading that oblique might not work with higher magnifications/resolving power.

[Scarodactyl]

Hmc is OK. I have a Zeiss inverted that has the condenser and a few objectives though some of the condenser filters are a bit delaminated. I like DIC a lot better.

[Rorschach]

Hmc is OK. I have a Zeiss inverted that has the condenser and a few objectives though some of the condenser filters are a bit delaminated. I like DIC a lot better.

That was the feeling I get from what I read; HMC isn't quite the substitute for DIC.

[Olivier21]

Therefore, it seems that oblique illumination is the avenue of exploration. I have read that this method induces quite a bit of chromatic aberrations but I do not know whether that also depends on the presence/absence of color corrections in the objectives and the condenser or not. Also remember reading that oblique might not work with higher magnifications/resolving power.

Hi Rorschach,
oblique illumination could give amazing results with cheap and low tech.
Take a look at this french forum :
http://www.lenaturaliste.net/forum/view ... 62#p128762
http://www.lenaturaliste.net/forum/view ... 22#p142522
yhe secund link show Vorticella videos.
Of course, that's not DIC... but nice results

Olivier