Enlarger
A darkroom device that projects a negative onto photographic paper to produce a print larger than the original.
Formula / rule
Magnification = image size / negative size
Measured in
× magnification
In depth
An enlarger is essentially a vertical camera in reverse: a light source, a negative carrier, a lens and an adjustable column. Condenser heads give crisper, more contrasty prints that emphasise dust and scratches, while diffusion and cold-light heads give softer results that hide them — a difference of about one paper grade.
Examples in practice
Raising the enlarger head to double the projection distance quadruples the exposure time needed.