Writings - Canon EF Camera
by Michael A R Grigsby
The late 1970s were a time of great shifts in photography. Building mechanically excellent cameras had just about run its course, and electronic circuitry was being produced more affordably and in smaller footprints. A sort of technology race was on, with manufacturers pushing their knowledge of using electronics to control cameras. One of the first battlegrounds was auto-exposure cameras--auto-focus lenses were well off into the future. Canon may well have been caught between selling a popular mechanical camera, and being forced to offer an auto-exposure system from manufacturers like Konica and Pentax.
Canon already had a superb line of cameras in the F-1 series, which competed head-on with Nikon's popular F series camera. Both were tough cameras built to professional specifications with interchangeable components that included motor drives and finders. Canon also produced a consumer based line of cameras, including the Canon FTb, introduced in 1971, and TX and TLb in 1974. In 1973 Canon introduced a rugged next-generation camera, designated the EF model.
The Canon EF had many unusual features for its time, but the big selling point is it was one of the first auto exposure 35mm SLR cameras on the market.
Looking much like an F-1 and trimmed in a beautiful black-enamel paint (no chrome version was available), the EF was a radical departure from the pure mechanical cameras of the 60's and 70's. While other manufacturers were experimenting with their first auto-exposure cameras, all other brands used aperture-priority exposure control--meaning the photographer set the aperture and the camera's exposure meter and linkage controlled the proper exposure by adjusting the shutter speed. Canon EF was a shutter-priority AE camera where the photographer set the shutter speed and the camera controlled the exposure by opening and closing the aperture of the FD lens.
Innovation didn't end with the shutter-priority exposure control. The EF was a hybrid camera: part mechanical and part electronic. The base plate housed two PX 625 mercury batteries operating at 1.35 volts. One battery operated the metering system while the other controlled the electronic shutter. Due to a voltage regulation system built into the EF's electronic circuitry, 1.5 volt batteries could also be used without damage to the camera, or affecting the light meter reading. Many users of the camera didn’t know that the EF had built-in voltage control, limiting the input to the camera to 1.3 volts, and subsequently purchased an MR-9 battery adapter to use the MS-76 cells—an unnecessary accessory. However, many found out how quickly the EF could expend it’s batteries when accidentally leaving the camera in the On position. No auto-shutoff was available on the EF. From 1/2 second to 1/1000 second (The EF's fastest shutter speed), the shutter was mechanical. You could remove the batteries and still have a functioning shutter at those speeds. A very unique feature of the EF was the ability to set exposure down to 30 seconds, and speeds from 1 second to 30 seconds were controlled by the battery and power system. This made the EF an extraordinary camera for low-light and special effects photography. Speeds of 15 and 30 seconds actually exposed the film for 16 and 32 seconds respectively.
A rather unique, but not new, shutter was built into the camera. While most other cameras of the day had a horizontally traveling cloth focal plane shutter curtain, the EF was a vertically traveling Copal Square shutter that was accurate as well as tough, much like that used in the Nikon Nikkormat EL camera. The EF is the only Canon camera that used a shutter made by another company.
By traveling vertically, the amount of distance the shutter had to cover was only 24mm instead of the 36mm horizontal distance. This also meant that the EF could use 1/125th of a second for electronic flash synchronization--a full stop faster than the typical horizontally traveling focal plane shutter at 1/60th second.
Also unusual was the EF's Silicon photocell light meter at a time when most other manufacturers used CdS (Cadmium Sulfide) meters. The Silicon photocell was much more sensitive than the CdS and provided the EF with a full 20 stop exposure value range (EV -2 to 18). This also gave the EF a remarkable range of ASA/ISO settings from 12 to 3200. Accuracy with the EF's metering was very good due to its center-weighted design that put more emphasis on the center, and lower part of the image to avoid the effects that a bright sky might otherwise have on an exposure. Users of older Canon cameras may have preferred the 12 degree semi-spot metering of some of the older Canon cameras like the FT QL. The Silicon photocell was also an active, not passive circuit and would use more current in dark shooting environments or even with the lens cap on.
Included in a standard kit was the camera body, nicely made web strap with rubber components to prevent slippage, and a leather battery packet to carry spare batteries--a nice touch, especially for those who leave the camera in the on position, where it would rapidly drain the batteries. Often the strap and plastic eyes caused brassing on the EF's paint surface above the strap eyes, and examples of bodies without the brassing are becoming more difficult to find. The kit usually included either the 50mm f/1.8 FD S.C. lens, or a much higher quality "normal" lens: the 50mm f/1.4 FD S.S.C. (Canon's Super Spectra Coating). A range of lenses were available and the same breech-mount was used throughout the Canon line of cameras during that time period. While the breech mount lens was unusual, it was very effective and ensured the lens was always in the ready position to be mounted on the camera. By pushing the lens toward the camera body, a well maintained breech mount lens would automatically rotate the retaining collar to a semi tightened position.
Early versions of the lens had a chrome front-ring (often referred to as chrome-nose FD lenses), and like the black version, featured a bayonet to allow a lens shade to be quickly attached. Later “nFD” lenses, mainly for the AE-1 line of cameras, were all black and made of polycarbonate plastic, leaving the user with the sense that newer lenses had a lower quality than the older, metal FD lenses.
Ergonomics is another area in which the Canon EF excelled. It was a comfortable size for most hands. While the prism and focusing screens were not interchangeable, it did have the heft of its professional big-brother: the F-1. Keeping in line with the notion that it was a shutter-priority camera, the shutter speed dial itself was very easy to use. Similar to the Leica M-5 of that era, the shutter speed dial extended out over the front of the body, making it easy to adjust with a quick movement of the right index finger. The camera could be easily turned on and off by clicking an on and off lever on the back of the camera with the right thumb, and the self-timer lever on the front of the camera also served as a depth-of-field preview lever, and mirror lockup switch (also adding to the value of the EF as a low-light camera).
Adjusting the ASA (ISO) was a simple matter of clicking on a chrome button next to the rewind lever, lifting up on the ASA dial, and moving it until the proper ASA was selected. To open the back, the rewind lever was spring loaded, and pulling it upward caused the back to release, allowing access to the film chamber. When the back was opened, the counter, located next to the shutter speed dial, was spring loaded and reset to S or Start. It was a typical "count up" variety and had a small magnifier glass on top of it to make it easier to read.
Both manual and electronic flash could be used on the EF by selecting the proper mode on the back of the camera. Also available was the Canon Speedlite 133D--the first flash unit to fully integrate with a camera’s exposure system in auto-mode. Two extra contacts on the flash shoe were used to connect to a special ring that attached to four or five lenses in the FD line, allowing for the integration of flash and camera. A plastic cover could be inserted into the hot-shoe, covering the flash contacts on the top of the camera. This piece is often lost, but doubled as an eyepiece shield to prevent extraneous light from entering the camera's prism when the eye was not against the camera. A PC connection (referred to in the EF's manual as a German flash connection) was available on the side of the camera and covered by a spring-loaded swiveling cover. By now you should be getting a sense of the attention to detail expended while designing the Canon EF.
During exposures of 1 second or longer, the red LED on the top of the camera flashed on and off to indicate the camera was in the middle of a long exposure. When the shutter closed, the LED stopped blinking. The bottom of the camera had a red button to test the batteries, and if sufficient, the same LED on the top of the camera would blink on and off until the red button was released. The LED's blinking speed helped indicate the freshness of the batteries.
Two variants of the EF were produced with the only difference being the focusing screen. The earlier, first versions (below serial number 330000) had a plain matte screen with micro-prisms, while later versions included a split prism.
Canon EF's were fairly expensive for their time, and combined with short five-year production run, the camera is somewhat rare.
In 1976, Canon ended production of the EF camera after the very popular AE-1 model was introduced in 1976, though new stock was available until 1978. The Canon EF should not be confused with the later EF-M model, and have very little in common.
I would like to acknowledge and extend my thanks to feedback from FD users at the Photo.net forum for graciously lending comments and insights into the EF. I am not alone in my belief that this is one of the finest 35mm SLR cameras ever made. Particular thanks to Mark Wahlster, Jeff Adler, and Richard Oleson.