Canon EF camera

lenses. The EF was built as an electronic version of Canon's top-of-the line F-1 camera. Because of this, the EF shares the F-1's rugged construction and tough metal body. Unlike the F-1, the EF doesn't support any motor drive for film transport.

The Canon EF contained a silicon photocell light meter with a range of EV 18 to EV -2 which measured light in a "central emphasis metering" pattern (also called center weighted average metering) with less influence from the top of the frame, to minimize underexposure due to a bright skyline. Note that this requires the camera to be held normally! Taking vertically oriented pictures requires some care by the user. The Canon EF could operate "Variable Aperture AE" mode (commonly called shutter priority) or full manual mode, where the operator would control both the shutter speed and the aperture. When used in automatic mode, it's possible to lock the current aperture value, then recompose the picture, if desired.

Automatic exposure required the FD-mount lenses. In 1975, the range of FD lenses available span from 15 mm fisheye to 300 mm telephoto, including three zoom lenses. Using manual exposure and stopped down metering, the Canon EF could also be used with the older FL-mount and R-mount lenses.

The EF used a unique shutter among Canon's 35mm SLRs: a Copal Square vertical-travel metal blade focal plane shutter. Unusually, long exposures (from 1 second to 30 seconds) were electronically controlled, while shorter ones (1/1000 second to 1/2 second) were mechanically controlled. This was very useful in conserving battery power, and allowed one to use the camera even with dead batteries. The light metering system's power switch turned on the meter, removed the lock from the shutter trigger button and let the film advance lever pop out 15 degrees from the camera body, all in one flick of the thumb.In the axis of the main switch, a multiple exposure button is located. Pressing this while cooking the shutter prevents advancing the film. The frame counter is also blocked, thus preserving the correct frame count.

The focusing screen of the Canon EF can't be replaced by the user. Early models feature a microprism circle, the later a split image screen with a microprism ring around it.

Powering the electro-mechanical shutter and light meter were two PX 625 1.35 volt mercury batteries. Because the EF contains a unique voltage control system, common 1.5 volt alkaline batteries can be used in lieu of the now-unavailable mercury ones (please see this article's discussion page for more information.)

The EF is the only camera in the manual focus Canon line of the 1960s and 1970s (which includes the FTb, the F-1, and the FT) that can be used with common 1.5 volt batteries without modification to the internal electronics. Like all pre-1987 Canon SLR's, the EF accepted Canon FD mount lenses. The shutter speed range was 1/1000th of a second to 30 seconds (in a beautifully pedantic touch, the 15 & 30 second settings actually give 16 and 32 seconds, thus preserving the doubling sequence), plus bulb. The X-sync was 1/125th of a second. The camera included setting for film speeds of 12 ASA to 3200 ASA.

The EF also featured a self-timer and a stop-down metering mode which could also be used for depth-of-field preview. Stopped down metering must be used with older Canon FL lenses. The mirror can also be locked up for long exposures, to minimise camera shake.

References

* Canon, Inc. " [http://www.canon.com/camera-museum/camera/film/data/1966-1975/1973_ef.html Canon EF] ". Part of Canon's online Camera Museum.
* Canon EF Camera " [http://www.mikegrigsby.com/mrg/html/canon_ef.html Canon EF Article] ". By Michael Grigsby.
* The Canon EF user's manual.