Abel,
These were done with a "compound" microscope, not a stereo. I have two stereo microscopes but the numerical apertures are (typical of most stereo's) too low to get really sharp images much above about 6X magnification (on sensor). So (as with this image) I'm using a vertical illuminator (BH2-UMA) on an Olympus BHA stand with their M SPlan and Neo S Plan objectives. I also use camera bellows with an assortment of lenses and objectives for many shots (such as the head and abdomen pictures referenced above), but those get posted over in a different forum section.
Rik,
Is this roughly correct? What have I missed?
It's exactly correct, and you never miss much, if anything

.
I'll refer back to the diagram in this post:
http://www.photomacrography.net/forum/v ... hp?t=10176
Without the polarizers (marked "A" and "B") I find the glare and reflection much too strong with epi-brightfield on most subjects. Epi-darkfield is far better in this regard, but then you've got the circular highlights to deal with if there are rounded reflective surfaces in the subject. The limited "fixed" lighting of the vertical illuminator sometimes makes it hard to get aesthetically pleasing light... sometimes it is fine, while with other subjects it just doesn't look all that great.