Canon III-A User Manual
Page 13
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recommended
only
for
microphotography
:etc.).
The
shutter
will
close
only
when
either
of
the two methods given above are used.
NOTE:
For speed slower than if25 sec. a solid tripod is essential and preferably a Canon Camera Holder.
IMPORTANT:
When using Flash Unit with the Model IV-S2 camera and making
exposures
with the High
Shutter Speed Dial precise flash amd speedlight synchronization will be affected if the Slow Shutter
Speed Dial is not set at 25. See pages 30-33.
LENS
APERTURE
SCALE
The
Lens
Aperture
controls
the
amount
of
light
entering
the
lens
and also'the Depth of Focus. Set the Lens Aperture (f’Stop) by turning the Aperture Scale
(knurled ring, see illustration) to the proper position. This is best determined with an exposure
meter^or following^the instructions given with the film.
NOTE:
The more light you want to entet the lens^ the larger must
be the Lens Aperture* Rotate the Knurled Ring while
looking into the lens and see the movement of the
diaphragm.
10
Index 'Made
Knurld Ring