Nikon FG Instruction Manual page 44

This provides an approx . 10-sec. exposure delay.
Independent of the shutter mechanism, the self-timer
can be set either before or after the film is advanced.
It can be operated at all modes except the B setting .
Slide the lever away from the lens as far as it will go,
cover the viewfinder eyepiece to prevent stray light
from entering through the viewfinder, then depress
the shutter release button After use, return the lever
to its original position . The self-timer is cancellable
any time before shooting by returning the lever to its
original position .
44
The film plane indicator (
--e- )
is engraved on the top
deck just behind the audio warning lever. It indicates
the exact position of the film plane inside the camera
and is used to measure the exact distance between
the subject and film plane, such as in macrophotog-
raphy. The distance between the film plane and lens
mounting flange is exactly 46 .5 mm .