Microscopes with transmitted light

Bottom illumination

— bottom lighting is a lighting system, the light from which is directed from the bottom up.

In conventional (not inverted) microscopes, such illumination is directed towards the objective through a hole in the stage. It is this type of illumination that is used for classical bright-field microscopy using through illumination; Thus, the lower arrangement of the illumination is traditional for biological microscopes and is provided for in most of these models. But the presence of this function in "stereoscopes" is not typical, although it also occurs.

In turn, in inverted microscopes, the upper and lower illuminations are actually “swapped”. Accordingly, in such models, this function is intended for examining preparations (mostly opaque) in reflected light, and the light flux is directed from the lens to the preparation.