Viewfinders
Like most professional 35 mm cameras of the 1970s, the F-1 had interchangeable viewfinders. To remove the viewfinder, one depressed the two small buttons at the rear sides of the finder, and slid the finder toward the back of the camera (or depress one button on the bottom of the Speed Finder).
The camera shipped with a standard pentaprism finder, called an "eye level finder" by Canon.
Other finders available included a waist level finder, Speed Finder, Booster T finder, and Servo EE finder.
The waist level finder was patterned after the design of waist level finders common on medium format cameras. It had a pop-up hood to shield the focusing screen from stray light, as well as a magnifier to help with critical focusing. The waist level finder did not allow the metering information to be seen.
The Speed Finder was unique to Canon. The speed finder had a unique arrangement of prisms which allowed the entire finder image to be viewed from 60 millimeters away. In addition, the speed finder was arranged in such a way that it could be viewed in either the eye level or waist level position. The speed finder was suggested for use when wearing goggles or anything else that could prevent the user from placing the eyepiece right up to their eye. The Speed finder allowed full metering.
The Booster T Finder and Servo EE Finder were both essentially variations on the standard eye level finder. The Booster T Finder contained an ultra-sensitive metering cell which could read as low as EV −3.5. Just like the metering range was shifted towards the dark side, this finder also shift the shutter speeds the camera provided towards the long end. Instead of the normal range (1 s – 1/2000 s), the Booster T Finder gave 60 s – 1/60 s. The shutter speed dial on the finder locked on to the camera's normal shutter dial and drove it through a coupling pin for the standard range of 1 s – 1/60 s. The finder also had a trigger button, which went through the finder down to the normal trigger button. When the Booster's shutter speed dial was turned further, towards longer times, the camera's dial stopped at the B(ulb) setting, and the finder kept the trigger button pressed for the duration of the exposure. The mechanics of this connection also resulted in the oddity that there was no 2 s setting, but 4, 3 and 1 seconds.
The Servo EE Finder added shutter priority automatic exposure to the F-1. A servo mechanism in the finder drove the aperture lever on the lens, stopping it down to the correct value. This finder used the same coupling pin on the shutter speed dial as the Booster T Finder did, to sync the finder's shutter speed setting with the camera. It required a cord connected battery magazine (8AAs) or the Motor Drive MF and a special power cord.
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