I used the MPE-65 set at 5x and f/2.8. I set exposure to manual and 1/10 of a second.
Lighting is one Jansjo lamp with no diffuser. I set my color balance to 3600K.
I am using a 20 micron step size, which is 12 motor steps for my rail. I set the bottom focus to 100 and the top to 760, which yields 56 exposures.
All said, this was a bust. Lighting was to harsh from the right, and even more than that, the photo is not sharp.
I had used a big blob of mineral tack to support one side of the specimen, which is a fairly big piece, and my theory is that the piece was slowly moving through the exposures, but who can say. The overall yellow light is due to light reflected from other parts of the specimen.
The answer is to break up this big piece, make micromounts from it, and try again!
I end up with this, field is 3.74mm.
Tom's Computer Info / tom@mmto.org