My scope is a Zeiss Standard, the objectives Leitz NPL Fluotar, the polarizer from a Zeiss Axio and the analyzer a Nikon. All them play well toghether for simple polarization work.
Some time ago I bought a Zeiss DIC (InKo) condenser with 3 prisms that seems designed to work with the dedicated DIC slider III, a very rare and expensive part (last one was sold in eBay for $1,600!) and a very restricted selection of planachromat objectives.
Unable to find this part and after being aware that the Olympus BX51 uses an apparently similar setup (Nomarski with only one common objective prism slider for all magnifications) when I was able to buy that slider (U-DICT) for a moderate price I decided to try. I'm going to mechanically modify the intermediate Zeiss tube with Telan lenses designed to allow the prism to fully allow mounting the Oly one.
After lots of tests and visits to Molecular Expressions website and some other sources, now I can get a reasonably good DIC effect

But the system is very far from perfect:
- The field of view background isn't fully uniform, with some light intensity gradient.
- The conoscopic image through a telescope eyepiece with the system set up at full extinction and both prisms in place is not dark but grey and with one diagonal band (similar to the view with only one dic prism in place although much less defined)
- The DIC effect is fairly good with the 40/0.75 and 50/1 objectives and the III prism, good but less uniform with the 25/0.55 with prism II and very subtle and uneven at 100/1.32. At lower mags I'm unable to obtain DIC

Following Molecular Expressions website http://micro.magnet.fsu.edu/primer/tech ... ation.html
the objective DIC prism must be situated in the back focal objective plane, a conjugate plane with the DIC condenser prism. In my setup it isn't but testing the microscope I find it isn't possible with the original Zeiss one because that plane is not imaged inside the intermediate tube. In the Olympus BX51, an infinite system, the objective DIC slider is placed in the infinite space, not very close to the objective, so I suppose that again it isn't at the back focal plane.
I suppose that my problems come, at least partially, from this inability to place the prisms at conjugate planes
I'm very confused.
I never did use a true DIC microscope, so I only have information about DIC from readings and images (like the magnificent micrographies posted here)
And now the questions for the DIC experts in the forum:
- When you have DIC properly setup, is the background fully even along the field of view or is there any gradient?
- I'm interested mainly in Olympus scopes and Zeiss older ones because Nikon, Leitz and most Zeiss systems use individual prisms for each objective. With that systems, is the condenser prism imaged in the position of the objective prism slider?. The easiest way to test it I found is to put a phase ring in the condenser and a painted microscope slide in the slider position and focus with a telescope eyepiece. Can you test it and tell me?
Waiting you comments, answers and suggestions...
...but please don't say "you're crazy, that system can't work", I already knew it
