The Canonet QL range was introduced by Canon in March 1965[1], as a development of the Canonet. They are 35mm rangefinder cameras with shutter priority CdS-meter controlled auto exposure and manual override. Each is fitted with the Canon QL quick film loading system.

The QL17 had a 45mm f1.7 lens, the QL19 an f1.9, and the QL25 an f2.5, set in Copal SV shutters. The 17 and 19 have speeds from 1/4-1/500s, and the 25 has 1/15-1/500; there was also a more basic QL 19E model, from November 1965 with a 1/15-1/500s Seiko shutter, recognisable by the self-timer lever being mounted beside the lens barrel, rather than on the barrel itself on the Copal models. The QL 17 has a battery tester. Later models of the 17 have a 40mm lens.

Early models are seen[2] with no hot shoe and the PC connector beside the lens barrel - which is all bare metal rather than having blacked rings, and a black-on-white QL badge; the top-plate is flat along the full length. Next to the viewfinder is a window to illuminate the bright-line in the finder, with a black area next to it, around the square rangefinder window. The frame counter is to the (users) top right of the advance lever. The CdS meter cell window, above the lens but inside the filter thread, is round.

Later models have a white-on-black badge, a plastic moulding on the advance lever, a hot shoe and a PC socket under a cover on the end, below the rewind crank; the rangefinder window now shows in the centre of the translucent window and there is no black area; the top-plate has a small step down to the winding lever/shutter release. The frame counter is now between the advance lever and the step, and the meter cell window is rectangular. The "new" models, from 1969, have an extra pin on the hot shoe to link to the Canonlite D Speedlite flashgun[3].

The latest model of the QL17 is the QL 17 GIII.