Entoloma mushroom

[lkudzma]

After spending some time using both the 1st generation and 3rd generation Zeiss DIC, I am now of the opinion that the first generation offering from Zeiss is the most convenient and performs superbly. Interestingly, it is best with select non-Zeiss objectives. Spike Walkers FAQ gives the Zeiss recommended objectives (including the 40X Neofluar). I have found that the Leitz NPL Fluotar 40/0.80, Leitz PL APO 63/1.4 oel, Leitz NPL Fluotar 100/1.32 oel and most recently the Nikon UV-F 40/1.3 glycerine objectives work superbly with the Zeiss 1st generation (arrow condenser) Prism III on a Zeiss Universal with Slider II. See an example with the Nikon glycerine objective below. This is an Entoloma mushroom gill surface showing the spore bearing basidia cells and the unusual prismatic spores of this Genus.

[Cactusdave]

Interesting. I think the posts on this forum have illustrated again and again that it is possible to get good, and even excellent DIC with mismatched components. The most obvious case being the use of an objective not recommended by the manufacturer of the other DIC components used. The only problem of course is that there seems no way of predicting objectives that will work well in such mismatched systems. The only way is trial and error.

DIC systems which do not emloy individual objective prisms mounted directly at the rear of the objective, seem most likely to be accommodating in this respect. My own experience with a Nikon DIC system on a Nikon Diaphot which does not employ individual objective prisms is that a variety of objectives give DIC that varies between useable and very good, either with the X10 or X40 condenser prisms, or with both. The list of objectives that work include Nikon objectives not intended for DIC use, like the Nikon UV-F 40/1.3 glycerine that you mention ( see the fourth image in this thread http://www.photomacrography.net/forum/v ... 725#112725 ), as well as objectives from all the other well known manufacturers such as Reichert, Wild, Leitz and Zeiss. I can see no pattern in the objectives that work and those that don't. I have examples of achromats, planachromats, fluorites, apochromats, and planapochromats that fall into both categories.

Since DIC uses polarised light I thought perhaps objectives would at least need to be strain free to work well in a mismatched situation, but I'm not sure if even that is true. Perhaps someone has tested to see whether that is a factor?

[Pau]

lkudzma.
I'm most interested in your DIC setup because I have a close one:
http://www.photomacrography.net/forum/v ... hp?t=15606

(now I also have the scarce III DIC slider). In most cases the Olympus slider works better than the Zeiss original one, with the exception of the NPL Fluotar 25X that works better with the Zeiss slider if I put a 63 NA condenser lens

Like you I can obtain decent (sometimes even good) DIC with some Leitz NPL fluotar objectives, better than with with the Zeiss Phase Neofluars.

But I can't get DIC with any of my 100X ones: Leitz PL fluotar 1.32 160/- Ph3, Leitz Pl Apo 1.32 170/0.17 and Zeiss Neofluar 1.30 Ph3.
I've just received a Zeiss Planapo 63 1.4 and to my surprise it works reasonably well with both the Zeiss and Olympus sliders (better contrast with Zeiss but better uniformity with Oly)
This is a puzzling matter

And now my questions:
- Do you need to change the condenser heigh to get good DIC while changing objectives? (I need to do it all the time, an evident symptom of mismatching)
- What objetives do perform well with the "I" condenser prism? (I can't get any DIC with it)

[Pau]

Dave, I fully agree with your comments

Since DIC uses polarised light I thought perhaps objectives would at least need to be strain free to work well in a mismatched situation, but I'm not sure if even that is true. Perhaps someone has tested to see whether that is a factor?

I've never used any objective specifically designed for pol or DIC, but most ones I've tried are perfectly valid for pol work (perfect black background with crossed pols without specimen), just with the exception of a damaged Olympus MPlan and some cheap or old no name school microscope ones. So I think that pol objectives aren't special, just certified to be strain free.

For DIC I think there is another factor: the back focal plane position to match the image of both Nomarski prisms, and, because I need to change the condenser heigh between objectives I think this isn't standardized both between makers and for not DIC objectives from the same maker. Does this makes sense?

[lkudzma]

Pau,

I've only now checked responses to this post. Sorry for the delay. As for 100X objectives, the Leitz 100 NPL Fluotar 1.32 P works well with Zeiss DIC version I (prism III). I posted an example a while back. For me, the 400X mag is most useful, so that is where I've invested most in checking things out. As we know, it's a trial and error exercise. I just recently bought a Zeiss 40X multi immersion Plan-Neofluar. I'll report back.

As Cactusdave said, strain free is important as well as back focal plane. A crap shoot, but some results are very good.

[naturephoto1]

Excellent.

Rich

[lkudzma]

Thanks Rich!

Linas