Canon FTb Instructions Manual page 13

Frame Counter
Each winding will advance the number of the frame counter,
indicating the number of pictures taken . When the back
cover is opened, the counter automatically returns to
starting position " S " .
Safety Device for Shutter
When the shutter lock lever around the shutter release
button is turned to .. L " position , the shutter is locked
and will not move . This device may be used when the
camera is carried in a wound condition.
Attaching the Cable Release
Optional Canon Release can be attached to 'the FTb by
screwing it into the threaded hole in the center of the shut·
ter release button . The use of a cable release is recom-
mended when photographing with extended time exposure
or slow shutter speeds, and for copy work.
Even if the shutter lock lever is at .. L" position, the
shutter will operate by using the release.
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