I got a few air bubbles, the distribution is somewhat uneven, and I used a few damaged frustules by mistake. Three broke free from the fixative during mounting and floated away too. As they were still visible under the coverslip I imaged them separately and Photoshopped them back into place. Bit of a cheat, I know, but hey...
So a partial failure really; but better than my first attempts and all part of the learning experience. Onward...
Circle is 1.3mm diameter. Fossil diatoms, Oamaru, N.Z. mounted in zrax. Imaged using 5d MkII on a Zeiss ICM 405 with a 10x PlanApo. Brightfield illumination, a stitch of 4 tiles, each tile a focus stack of 20-25 images.
Particularly happy about the even background illumination. That's straight off the camera - no photoshop involved. I spent some time tweaking the Koehler illumination for "near perfection" recently and it's really paid off. Makes mosaicing of images a breeze now.
) and the photography. I have photographed a few circles of this sort using darkground, but I know from experience getting a really nice bright field image such as yours, evenly illuminated, is a real challenge. Congratulations. 
I would be interested to hear how you are manipulating the diatoms, do you have a micro-manipulator? Also what type of microscope and photography setup are you using?
