Anastigmat
Encyclopedia
An Anastigmat or anastigmatic lens is a photographic lens
Photographic lens
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...
completely corrected for spherical aberration
Spherical aberration
thumb|right|Spherical aberration. A perfect lens focuses all incoming rays to a point on the [[Optical axis|optic axis]]. A real lens with spherical surfaces suffers from spherical aberration: it focuses rays more tightly if they enter it far from the optic axis than if they enter closer to the...
, coma
Coma (optics)
In optics , the coma in an optical system refers to aberration inherent to certain optical designs or due to imperfection in the lens or other components which results in off-axis point sources such as stars appearing distorted, appearing to have a tail like a comet...
, and astigmatism
Astigmatism
An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances...
. Early lenses often included the word Anastigmat in their name to advertise this new feature (Doppel Anastigmat, Voigtländer Anastigmat Skopar, etc.). All modern photographic lenses are close to being anastigmatic.
The first Anastigmat was designed by Paul Rudolph
Paul Rudolph (physicist)
Paul Rudolph was a German physicist who designed the first anastigmatic lens while working for Carl Zeiss. After World War I, he joined the Hugo Meyer optical company, where he designed most of their cine lenses. -Work:...
.