1892 II. 43 Unscrew the back combination and use the front alone in situ, thus gaining the length of the lens mount.
1938 H. Windisch vi. 166 A focusing screen is applied to the lens mount.
1972 Horne & Markham in A. M. Glauert I. ii. iii. 354 Optical bench manufacturers make a large number of lens mounts and carriers.