Optical printer

/ˈɒptɪkəl pɹˈɪntə/

/ˈɑːptɪkəl pɹˈɪntɚ/

Optical printer

a device used in filmmaking to duplicate, manipulate, and enhance film negatives, positives or prints using optical techniques

Examples

1. These tricks were accomplished with optical printers, which let them shoot and light two images or scenes separately, and stitch them into one.

2. Around the mid 20s he started working more, doing patent research, developing cameras, developing optical printers and things of that nature.

3. Finally, you combine the two pieces of film in an optical printer, and, voilà: special effect!!!