While looking for a stereo microscope, I came across some information
that might be of interest. Image scanners can be used to acceptably
magnify anything placed on the scanning surface and they usually have a
good depth of field. Acceptable magnification for my 600 dpi scanner is
about 40x allowing it perform some of the functions (cubital index,
damaged varroa, infected trachea??) of a dissecting microscope. Those
with newer higher resolution scanners might be able to do much better.
 
When using the scanner set the scanning resolution to the highest
non-interpolated value.
 
Best Wishes
D. Murrell