The following initial tests are from a water sample collected outdoors, not fixed and not stained, imaged with UPlanApo 40x 0.85 (air), U-DP40 condenser DIC prism, U-ANT analyzer DIC prism, direct projection on Micro 4/3 (Olympus E-M1), single image (no stacking) with standard 100W halogen illuminator and built-in daylight compensation filter. I cropped away most of the picture area and reduced to 25% of original size (the 20 Mpixel images contain plenty of empty magnification). The scope is still not set up for immersion and focus stacking, and this is as high as I can go with magnification for now.
The DIC results I am getting with a 10x U-ACH and U-DP10 prism, and a UPlanApo 20x and U-DP20 prism are overall quite similar to these. I also have the U-DP100 100x prism, but it does not seem to give very different results from the 40x prism with the UPlanApo 40x.
Also a question: The U-UCDB-2 condenser has individually centerable prisms/annuli, but I don't see any difference when operating the centering controls with DIC. Is the centering only used with phase annuli?

Pollen with ?diplococci (and air bubbles)

undetermined, not stained, adjusted for maximum DIC pseudo-relief. This was almost invisible in brightfield.