Nikon Camera F3AF - Manual (Page 63)

Stop-Down Exposure Measurement
When using a non-AI lens or certain close-up accessories, you
must push the meter coupling lever release button
®
and lock
the meter coupling lever ® in the “up" position before mounting
a lens or attaching an accessory. In this case, the diaphragm in
the lens does not link with the meter coupling lever on the
camera body. Therefore, you must perform stop-down metering.
The procedure is as follows:
For non-AI lenses with automatic diaphragms
On auto: Push the depth-of-field preview button ® all the way in
and hold it as you trip the shutter.
Caution: If the depth-of-field preview buttoh is not depressed all the way,
the mirror ® may remain in the "up" position.
On manual: Select a shutter speed. Then hold in the preview
button and turn the lens aperture ring # until the
-■¥
symbol
appears in the viewfinder. Release the preview button and take
the shot.