A Schmidt Camera (or Schmidt Telescope) is a Reflector Telescope with a spherical Primary Mirror and a lens to correct the spherical Aberration (called the Schmidt Corrector Plate). They are relatively easy to construct at a given size, because spherical mirrors are easier to grind and they have a very wide Field of View, especially suitable for Astronomical Surveys. However, the Focal Plane is, in fact, not planar but curved, thus requiring unique design of the image recording, such as curved photographic paper in the photography age. The general design of the Schmidt camera was developed by Bernardt Schmidt in 1930. Variants of the Schmidt camera combine it with other telescope designs, e.g., the Schmidt-Newton Telescope.
Palomar 48 Inch Telescope (P48)
UK Schmidt Telescope (UKST)