Canon Canonet repair & common faults
Excellent coverageThe Canonet is Canon's compact 1960s to early 1970s rangefinder line, built around a leaf shutter lens unit and, on the QL and G-III models, a coupled CdS meter feeding an automatic or match needle exposure system. Its mechanisms are dense and electrically coupled through a single exposure meter unit, so faults tend to show up as either a sluggish shutter or a dead or erratic meter rather than anything dramatic.
Leaf shutter lens unit · Coupled CdS exposure meter · Rangefinder focusing with double focus lens · Trigger wind film advance
Common Canon Canonet faults
Canon Canonet shutter won't fire or sticks open
Usually the shutter release linkage or the diaphragm blades in the lens unit have gummed up with old lubricant, which drags on the blades and stalls the release. On these leaf shutters the blades and release mechanism sit close together, so a sticky shutter often points to the blade set needing attention too. Check the wind lever has fully advanced before assuming it's the shutter itself.
Canon Canonet exposure meter reads wrong or dead
The exposure meter unit houses the photoelectric cell, the galvanometer and the EE calculator that ties readings to the aperture ring, and any of these can drift or fail with age. A dead needle points to the cell or its wiring, while a needle that moves but reads consistently wrong suggests calibration drift in the calculator linkage. Confirm the meter switch is set and, on battery models, that the cell isn't fooled by a flat or wrong-voltage cell first.
Canon Canonet rangefinder patch dim or doubled
The range-viewfinder is a separate optical unit with its own half mirror, mirror and correcting mirror, and the silvering on these mirrors degrades with age and humidity, leaving the focus patch faint or washed out. A doubled or misaligned patch instead points to the mirror mount or connecting linkage having shifted rather than the silvering itself. Neither fault affects the shutter or exposure, only focusing accuracy.
Canon Canonet film advance feels stiff or won't wind
The winding mechanism is a fairly dense gear and clutch assembly linking the wind lever to the sprocket and take-up spool, and old grease turning gummy is the common cause of a stiff or catching advance. A wind lever that moves but doesn't advance the film usually means a clutch or feeding claw has slipped rather than anything to do with the shutter. Rule out a jammed or misloaded film cassette before assuming it's mechanical.
Canon Canonet light shields perished, light leaks on film
These cameras use multiple light shield strips around the back cover, body case and lens mount rather than one long seal, and on a camera this age they've usually turned to crumbling foam or sticky residue. Leaks show as fogging or streaks near the frame edges, worse in bright conditions or long exposures. This is a materials fault, not a mechanical one, and is unrelated to shutter or meter problems on the same body.
Canon Canonet aperture blades sticky or sluggish
The diaphragm blades sit in the lens unit alongside the shutter charge ring, and migrated lubricant from the helicoid or shutter mechanism commonly reaches them, leaving the aperture slow to close or hesitant at smaller settings. This is a common companion fault to a sluggish shutter on the same lens unit rather than a separate failure. It affects exposure consistency more than it stops the camera firing outright.
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Try it now ›Scatto is a reference tool for people who service film cameras. It explains mechanisms and quotes service data, but it cannot see your camera at the bench, so verify anything load-bearing before you act on it.