photo enlarger how does it work?

Answer 1

A photo enlarger comprises a light source, a system of optical lenses, an arrangement to hold the photo negetive in position, generally between the light source and the lens system, and a flat board on which the photo sensitive printing paper is clipped. Light passes through the negetave and a real image is formed by the lens system on the printing paper which is exposed for a predetermined time. After the exposure the pringing paper is removed and developed.

Answer 2

For enlarging negatives, like a slide projector. For enlarging opaque prints, like an epidiascope, which lecturers use to project an enlarged image of a solid object onto a screen so a room full of students can all see it. Both devices use lenses to project a diverging beam onto a screen.