Other forms: darkrooms
A darkroom is the red-lit room where film is developed. Work in the darkroom, a darkroom enlarger, set up a darkroom.
The light is red because black-and-white paper is blind to that end of the spectrum, so you can see while the paper cannot. Colour film has to be handled in total darkness. Digital photography emptied nearly every darkroom within a decade.
1noundarkroomThe room where photographic film is developed.
“He developed his black-and-white photos in a small darkroom under the stairs.”
darkroom is a room.
Dark plus room, from the nineteenth-century practice of developing plates away from light.
From dark + room.
Etymology from Wiktionary, CC BY-SA