The Canon Canonet G-III QL17 is a coupled-

rangefinder A rangefinder (also rangefinding telemeter, depending on the context) is a device used to measure distances to remote objects. Originally optical devices used in surveying, they soon found applications in other fields, such as photography an ...

, leaf-shuttered, fixed-focal-length 35 mm camera first manufactured by

Canon Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western can ...

in 1972. It features fully shutter-priority automatic exposure and fully manual shooting modes. The Canonet G-III is the third generation of ''

Canonet The Canonets were a series of rangefinder cameras made by Canon from the early 1960s to the early 1980s. They were aimed at enthusiasts on a budget and more discerning point-and-shoot photographers. These cameras are considered to have made Can ...

'', following the original Canonet and the New Canonet. The G-III features a 40 mm 1.7 with six elements in four groups. The integrated lightmeter provides shutter priority and manual modes. The sensor is located on the forward part of the

lens A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...

, which allows use of filters without manual compensation of exposure. The Canonet can use standard flashes, or the Canolite D which was custom-designed for the Canonet.

Exposure meter

The exposure meter uses a PX625

mercury battery A mercury battery (also called mercuric oxide battery, mercury cell, button cell, or Ruben-Mallory) is a non-rechargeable electrochemical battery, a primary cell. Mercury batteries use a reaction between mercuric oxide and zinc electrodes in an ...

, which is now discontinued. The alkaline equivalent can be used, but the different voltage, different discharge curve, and absence of voltage regulation circuit cause incorrect metering that results in between 1.5-f-stop underexposure at the beginning of the life of the alkaline battery and 1.5-f-stop overexposure at the end. Furthermore, the mercury battery has a life span of several years, compared to a few months for the alkaline battery. This degree of incorrect exposure is tolerable with negative colour or black-and-white films, but is more noticeable with slide films. Many users will use a 1.4-volt hearing aid battery or adapters with Schottky diodes that allow use of SR-44 battery with better results. A zinc-air replacement battery can also be used. This battery has the same voltage as the PX625 mercury battery, and therefore is seen as a viable replacement by many. The G-III camera made checking the battery easier by the addition of the battery check button on the side of the viewfinder eyepiece. A lamp on the camera would light when the battery was still good.

References

External links

Canon Canonet GIII QL17
by Karen Nakamura
Canon Canonet G-lll QL17 group at flickr

Canon rangefinder cameras {{camera-stub