Canon Booster T Finder for F-1, F-1 (2nd Style)

The Booster T Finder permits metering with the F-1 down to the level of EV -3.5 or 15 sec. at F/1.2 with ASA 100 film. It contains a built-in electronic timer to measure long exposures, and a light that blinks at 1 second intervals during exposure of from 3 to 60 seconds. An eyepiece shutter is provided so that light entering through the eyepiece will not cause inaccurate exposure metering. For full-range metering (the Booster meters from EV10 to EV -3.5; the F-1 meters from EV3 to EV15) the metering system of the F-1 can be used in bright light, as it is used noramally. Two auxillary lamps are included in the design of the Booster T Finder. One illuminates metering information for the Booster T when it is in use, the other illuminates the standard metering function when the F-1's built-in meter is used.