Refletion microscope without beam splitter

[j.stirling]

The screw is 6.5mm long and 2mn wide so not far off the size you are looking at.

This throat measured the field of view at mine and max magnification

First build - Field Dissection Microscope

After fumbling with the software it’s now time to have a look at the optics and its performance. As I wrote above I’m using a cheap lens with a focal lenght of 16 mm at f/2.0, according to the description on amazon. On the lens it says: 16 mm, 5MP, 1/2.5", IR. The M12 thread has a lenght of 12 mm with a backfocus of 4 mm. The M12 mount which I printed has a thread with usable height of about 10 mm. With this lens at the uppermost position of the focuser with minimum magnification I get a FOV …

I think with the normal microscope you will likely struggle with depth of field issues