Mamiya C Camera

Mamiya TLR System Summary - Chapter 15

15 Glossary

15.0 General medium format terms and acronyms

I will add to this list as I come across terms that may not be self-explanatory. It isn’t intended to be definitive.


A layer applied to lens glass surfaces to alter their refractive characteristics. Multi-coating uses more than one coating to correct for different behaviour by different wavelengths (colours) of light.

Chimney Finder

Basically an enclosed finder with an adjustable eyepiece lens on the top. It may have light metering, or extra central magnification as an option. Really good at excluding extraneous light, but significantly bigger than the waist-level finder, and has to be used at eye-level.

Helical focus

A focus mechanism where a spiral thread in a tube is used to advance or retract a lens as the lens is rotated. Used extensively on rigid body cameras. Compare with rack and pinion focus, as noted in the Mamiya-specific section.

L Grip

Camera grip with a vertical handle attached to a base that screws into the base of the camera. Various shutter release options and accessory mounts.


The different image content that results from slightly different viewpoints. What you see isn’t exactly what you get.


A five-sided prism (obviously!) that provides an eye-level, right-way up, left to right correct view of the subject.

Pistol Grip

Hand grip that attaches to the base of the camera, and generally resembles the grip on a pistol. Good wrist ergonomics for holding a camera high, but the camera weight can be an issue.

Taking lens

In a twin lens reflex camera, the lower lens used to expose the film.

Viewing lens

In a twin lens reflex camera, the upper lens that is used for composition and focusing.


Waist-level finder. The basic ‘flip-up and look down’ finder type. Consists of a folding light shield around the camera focussing screen. Image is right-way up, but left to right reversed.

15.1 Mamiya TLR specific terms


Mamiya device to move the camera at right angles to the lens axis and parallel to the lens board by 50mm (2"). This moves the taking lens to the viewing lens position to correct parallax at close distance.


A finder that uses mirrors to achieve a right-way up, left to right correct eye level image. Similar in effect to a pentaprism.

Rack and pinion

A gearing mechanism that uses a toothed bar or track in conjunction with a toothed roller at right angles to the bar.