Flatness

The flatness is in the photo technology is an important property of photographic papers and films.

With the exception of very simple meniscus lenses , all optical systems in photography are designed to achieve the smallest possible field curvature , i.e. to produce images exactly in one plane . However, films and photo papers tend to curve in a preferred direction, which would lead to partial blurring. Various measures are common to improve the flatness of the recording materials:

• Flat films are given a gelatin layer on both sides so that tensions, in particular due to changes in air humidity, are balanced out
• In cameras springy be Filmandruckplatten used
• Some Contax models even use a ceramic vacuum plate that sucks the film onto them through holes.
• As you zoom in photo lab find magnifying frame , glass plates or vacuum frame using

In order to reduce problems with the flatness of photographic materials, it is primarily a question of suitable storage, in particular insufficient humidity, but temperatures that are too high also impair the properties. In the case of roll film , it is sometimes recommended to transport the film immediately before taking the picture.