Microscope parameters for whole blood alalysis
As I found out in medical lab-groups, the most lab-workers use 100x Objective (oil or dry Leica objectices) and 10x ocular. This results in 1000x and the images like the below.

My idea was to use 20x objective (as it is much easier to handle) and 14MP camera. The erythrocyte should have the resolution about 60x60 pixels then, which should be enough for the differentiation.