i post some unusually shots i got by modifing voltage of lamp and light path of darkfield illumination.
First two i used built in filters on base of Photomicroscope by pushing a bit (not completely) the buttons filters; this way diatoms appear like a relief silver-metallic shield.
third image, by setting very low voltage of 100w alogen lamp...it look like a golden diatom..
best
arturo


