Canon's first FL-mount SLR — the FX, CdS meter, cloth shutter to 1/1000, manual, 1964.
The Canon FX, introduced in 1964, was the first Canon SLR to use the new FL breech-lock lens mount, replacing the earlier R mount and beginning the lineage that led to the FD system. It sat as a mid-range body in Canon's mid-1960s SLR range and introduced through-the-lens compatible handling with an external CdS meter.
As a 35mm SLR the FX used the Canon FL breech-lock bayonet and a cloth focal-plane shutter covering 1 second to 1/1000 plus bulb. It carried a body-mounted CdS meter, coupled to the shutter and aperture settings, read externally rather than through the lens, with exposure set manually via match-needle. The CdS meter required a battery, but the mechanical shutter fired without power.
The FX suits users and collectors interested in the start of the FL system and manual, match-needle shooting. Its CdS metering is more sensitive than the selenium cells it replaced, though the external meter window means metering does not account for filters or close-up attachments. It is a solid, mechanically dependable body for deliberate photography.
On the used market, note that the FX's CdS meter was designed around a mercury cell; check meter response and be aware that period 1.35V mercury batteries such as the PX625 are no longer sold, so readings may be off without an adapter or recalibration. Inspect the cloth shutter for capping and accuracy, look for perished foam seals, prism haze or desilvering, and confirm smooth advance and rewind. FL lenses adapt to mirrorless bodies.