Thanks a lot for your encouraging comments!
I was also really happy with the glass-like appearance, as with incident light I try to display the diatoms as if they are lying in front of you in the table and you can "touch" them.
@James - yes, the diatoms are lying dry, no coverglass on a slide.
Sometimes, classic transmitted light is beautiful, too (ok, the image is inverted and tinted, but the rest is straight forward transmitted light):
edit: completely forgot, light is a bit oblique...
Inza, Russia
