If you just bought the camera then you will want to know how to use a canon FTb in stopped-down metering mode. Pushing the lever anti-clockwise enables the auto self-timer function; however, pushing the lever clockwise (towards the lens barrel) performs the stopped-down metering function.
Stopped down metering is achieved through the lever at the front, which also doubles as the timer. Moving the mechanical switch to the 'L' position, locks the 'stopped-down' metering mode.
What is “stopped-down” metering?
Simply put, in 'stopped-down' metering mode you are taking a light level reading (or metering) whilst the aperture is set to the desired setting.
Full aperture metering mode, used by amateurs, is when the aperture remains fully open and stops-down (closes) to the desired level a fraction of a second before the shutter is depressed. It then returns to the fully open state after the shutter releases.
The reason why it works like that is that the viewfinder image can get very dark if the aperture is set to the desired position all the time. As a result, the aperture engages to the desired setting for a brief period just before the shutter releases.
If you are using a tube between the lens and the camera body, then the linkages from the lens can no longer convey information to the camera body. Stopped-down mode is useful with FL lenses that do not have a full aperture metering capability.
This Article Continues...Canon FTb Flash Mount Meter Booster
How to Load a Film Camera
How to use a Canon FTb
Canon FTb Specifications
Canon FTb Accessories
Canon FTb FD Lens Mounting Compatibility
Canon FTb Battery Replacement
Canon FTb Shutter Speed
Canon FTb Stopped Down Metering