Canon FT QL 1966

The Canon FT QL is a 35mm single-lens reflex camera introduced by Canon of Japan in March 1966. It has a Canon FL lens mount compatible with the large range of FL series lenses. The FT can also operate the later Canon FD series lenses in stop-down mode, but the earlier R series has a different lens aperture mechanism and cannot be used, although the bayonet fitting is similar. The standard kit lenses were Canon's 50mm f/1.8 ; 50mm f/1.4 and 58mm f/1.2, the body-only option was offered later.

FT QL was introduced in March 1966, a year after the pellicle mirrored Canon Pellix. However it differs from the Pellix models, having a normal quick-return reflex mirror and offering stop-down TTL metering. The TTL metering is semi-spot in nature and works through a prism incorporated in the viewfinder condenser/screen assembly. The later Canon F-1 has a similar prism for metering in its removable screen. The Canon FT viewfinder screen is not user changeable. The pentaprism finder is fixed like the similar FX and FP models but unlike some earlier Canon R reflexes.

The cloth focal plane shutter has speeds from 1 sec to 1/1000 and B. The electronic flash sync. speed is 1/60. A delayed action timer gives 8 - 10 seconds delay, using the same front of body lever that actuates the stop-down metering. The mirror can be locked up for vibration reduction or for use with special FL lenses like the original 19mm f3.5 wide angle which projects deeply into the body and would foul the mirror.

The QL designation was a reference to Canon's ingenious and successful "quick load" system. A stainless steel sprung hinged device on the inside of the body rear door makes film loading easier than was normal at the time.

Canon Inc. (キヤノン株式会社^?) is a Japanese multinational corporation that specialises in the manufacture of imaging and optical products, including cameras, camcorders, photocopiers, steppers and computer printers. Its headquarters are located in Ōta, Tokyo, Japan.

A single-lens reflex (SLR) camera is a camera that typically uses a mirror and prism system (hence "reflex", from the mirror's reflection) that permits the photographer to view through the lens and hence see exactly what will be captured, contrary to viewfinder cameras where the image could be significantly different from what will be captured.

Prior to the development of SLR, all cameras with viewfinders had two optical light paths: one path through the lens to the film, and another path positioned above (TLR or twin-lens reflex) or to the side (rangefinder). Because the viewfinder and the film lens cannot share the same optical path, the viewing lens is aimed to intersect with the film lens at a fixed point somewhere in front of the camera. This is not problematic for pictures taken at a middle or longer distance, but parallax causes framing errors in close-up shots. Moreover, focusing the lens of a fast reflex camera when it is opened to wider apertures (such as in low light or while using low-speed film) is not easy.

Most SLR cameras permit upright and laterally correct viewing through use of a roof pentaprism situated in the optical path between the reflex mirror and viewfinder. Light, which comes both horizontally and vertically inverted after passing through the lens, is reflected upwards by the reflex mirror, into the pentaprism where it is reflected several times to correct the inversions caused by the lens, and align the image with the viewfinder. When the shutter is released, the mirror moves out of the light path, and the light shines directly onto the film (or in the case of a DSLR, the CCD or CMOS imaging sensor). The Canon Pellix film camera was an exception to the moving mirror system, wherein the mirror was a fixed beamsplitting pellicle.