Definition & Meaning of "optical printer"

What is an "optical printer"?

An optical printer is a device used in filmmaking and animation to make copies of film negatives, positives, or prints, or to combine multiple film elements into one. It operates by projecting images from one film reel onto a screen and then capturing those images with another film reel. This process allows filmmakers to create effects, such as combining different scenes or adding special effects, by manipulating how the images are projected and captured. The optical printer helps achieve high-quality results and refine visual effects for movies and animations.