in photography, device for producing a photographic print or negative larger than the original negative or transparency. The enlarger consists of a projection system, or head assembly, mounted on a horizontal base. The head assembly includes an enclosed light source, a holder for positioning and flattening the negative, a lens for projecting the image onto the base (which holds the paper), and a mechanism for focusing the image. The head assembly may be raised or lowered to adjust the size of the print.

A filter drawer between the light source and the negative permits the insertion of colour filters or variable contrast filters. Modern enlargers designed for colour printing generally incorporate adjustable filters within the head assembly itself.