Olympus OM-2 - Manual (Page 13)

APERTURE RING AND MANUAL SHUTTER SPEED RING
Aperture Ring
The opening (aperture) in the lens diaphragm is
marked in F stops on the aperture ring. The higher
the F number, the smaller the lens opening (less
light) and provides greater depth of field than
lower F numbers (see page 25).
When setting the aperture ring, you may use either
the click-stop positions or any in-between settings
to obtain precise exposure control.
NOTE: All lenses in the OM System (except cer-
tain specialized lenses) provide fully automatic
diaphragm control allowing you to focus and
compose your picture with the lens fully open.
The diaphragm will automatically close to the
pre-selected F stop at the moment of exposure.
And immediately re-open after exposure.
Manual Shutter Speed Ring
Shutter speeds engraved on the manual shutter
speed ring are used only for non-automatic cam-
era operation. B indicates "bulb" at which set-
ting the shutter will remain open as long as the
shutter release button is held down. The other
engravings indicate fractions of a second; for ex-
ample "T" for 1 second, "2" for 1/2 second .....
up to "1000" for 1 /1000 second. To set at "B",
rotate the ring while pressing the B LOCK but-
ton at the lower left of the body mount.
Be careful that shutter speeds are set only at
click stop positions. Make sure that the selector
lever is set at a click stop position.
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