How a Photo Lab Makes Pictures

Unlike the home darkroom, photo labs used sophisticated machines.

There are a multitude of steps involved in making pictures at a photo lab. Photo technicians turn film into finished prints by combining traditional photography techniques and newer digital technology.

Getting the Image

Photo labs use a film processor to develop film in an assembly-line fashion in complete darkness. These machines contain up to six chambers that the uncut film passes through in a timed sequence. The film starts by being dipped into a water bath to ensure the film is at the right temperature for development.

The film is then dipped into a developer for a predetermined time, based on the type of film being developed. The film then passes through another water bath to rinse off the developer before being plunged into a "stop bath," which halts any further development of the film. The film is again washed before being dunked in a "fixer," which makes the image on the film permanent and viewable in the light without fading or disappearing completely. Finally, the film passes through a dryer before exiting the film processor.

Preparing the Image

A technician uses a machine called a "minilab" to scan each image into a computer that automatically adjusts the image for brightness, contrast and color balance. Before computers and scanning technology were available, a minilab would project each image directly onto photographic paper using various filters to adjust for contrast and color balance.

Making the Print

The scanned images are printed onto photographic paper designed specifically for minilab printers. Depending on the model of the minilab machine, a photo lab can print various sizes of photographs by loading different sizes of photographic paper into separate paper trays in the machine. Before digital photography, photo prints would have to go through a similar developing process as the film. The print would be submerged in developer, stop bath and fixer and then through a dryer. These steps would be done in complete darkness, within the minilab, before emerging into the daylight.