Horizontal enlargers consist of a lamphouse, condenser, negative carrier, bellows and lens. The holder for the paper is mostly separate. They were popular from the 1880s and still available in the 1930s.

The Focomat is a very well engineered enlarger introduced in 1934, a little later (c.1935) a locking lever was incorporated to clamp the masking frame to the baseboard. There are three spring catches around lens holder to switch the auto-focus between formats. The negative number is displayed through a red filter onto the baseboard. The masking frame has adjustable borders.

Vertical enlargers appeared in the 1910s.