Microscopes need lots of expertise resulting in limited reward. You need a MINT protractor (follow the directions carefully...it may take a couple of days...rest often...check and recheck) and if you have a VPI arm or similar, you need a Fozgometer with its accompanying test record.. a scale for weighing,.a flashlight, and a 10x hand held glass. Its not hard to set up a cartridge, just tedious. That's why you should do it yourself...are willing to take the time and energy to do it right.