Camera lens throat
Inner diameter of a camera lens mount
From Wikipedia, the free encyclopedia
A lens throat is the inner diameter of a camera lens mount. It is the width of the opening, measured between two non-obstructed points, i.e., not including the mounting tabs on a bayonet mount.[1]
Canon stated, "Throat size is crucial for determining the angle of incidence and provides us with a more realistic picture of the mount's capabilities."[2]
In an interchangeable lens camera, the combination of the throat diameter and the flange distance affect the angle of incidence. A larger throat and a smaller flange distance make for a larger angle of incidence, allowing for more flexibility in lens design, without requiring retrofocus designs for wider angle lenses.[1]
The elements of a lens elements can have wider diameters with a larger throat diameter, meaning that surface curvature can be less drastic. And with a well-designed lens with lessened surface curvature you get less chromatic aberration.[3]
