A telescope specifically designed for photographing comparatively wide areas of sky. Traditionally, an astrograph is a refractor with a lens corrected to give its best images at blue wavelengths, to which early photographic emulsions were sensitive. The astrograph is mounted together with a visual refractor of similar focal length for accurate tracking on a guide star. Today, Schmidt cameras are used instead, typically having fields of view of 6°. See also Normal Astrograph.
Subjects: Astronomy and Astrophysics.