Backup Mechanical Release Lever; Depth-Of-Field Preview Button - Nikon F3 Instruction Manual

Backup mechanical release lever
®
This lever is provided as an alternative method of trip-
ping the shutter in case the camera's batteries become
weak or completely exhausted . To operate the lever, first
use your fingernail to pull
it
down to the ready position.
Then push
it
down to trip the shutter. The shutter operates
at a mechanical speed of approx . 1/60 sec . regardless of
the setting on the shutter speed dial. Even when the
batteries are exhausted, you can still make time ex-
posures by setting the dial to "T" and using the backup
mechanical release lever to trip the shutter.
Caution :
II you advance the liIm while holding down the backup
mecha·
nical release lever, the shutter will fire immediately at the completion
01 the film advance stroke, thus wasting a lrame.
Also if you loilto advance the film completely and then
use
this lever to
trip the shutter, the mirror
®
will remain in the "up" position until the
advance lever stroke is completed.
Depth-of-field preview button
CD
This control allows you to get a visual impression of the
various parts of the scene in front of and behind the main
subject which will appear sharp in the final photograph
(see the photos on the next page.) To operate this control,
push the button while looking through the viewfinder. If
the lens is set to anything other than maximum aperture,
the image on the focusing screen will give you an indi-
cation of exactly what will be in focus in the final photo.
The image progressively gets darker as the le ns aperture
gets smaller.
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