Hasselblad SWC/M - Exposure value calculation; Focusing C lenses

Shutter speeds: 1 s to 1/500 s and B. The B
setting enables you to make exposures lasting
more than one second. The shutter remains
open as long as the shutter release remains
depressed. Use a cable release at slow shutter
speeds. The numerals ‘1’ to ‘500’ designate
the speeds 1, 1/2, 1/4, 1/8, 1/15 s, etc.
The green scale is used for calculating expo-
sures when lighting is so weak that a 1 s expo-
sure is inadequate.
Exposure values are set on the red scale.
Exposure values (Fig. 63)
The aperture/shutter speed combination
opposite the central index (12) determines the
exposure. Each such combination has an
equivalent exposure value (6).
The exposure value is determined with an ex-
posure meter, such as the Hasselblad knob
with exposure meter.
The value obtained is set opposite the index
(3). Once the correct exposure value is set this
way, a correct exposure will be obtained with
any shutter speed/aperture combination set
opposite the central index (12) using the grip
ring (15). (Not applicable to B.)
Time exposure
C lenses have a green shutter speed scale to fa-
cilitate the caleulation of correct exposures
lasting longer than 1 s. The green figures on
the scale designate full seconds from 4s to 125
s (B stands for 2 seconds).
Example: The exposure meter indicates an ex-
posure value of 7. This would be equivalent to
an exposure of e.g. f/2.8 at 1/15 s. If f/22 is
preferred for more depth of field, turn the
grip ring (15) for shutter speeds/apertures to
B. Read off the number on the green scale
opposite 22, i.e. 4 (seconds) in this case. Re-
38
Fig 63
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2
б
Г
* D |
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tain the B setting. Uncouple the diaphragm
ring so that 22 is opposite the central index.
Then make a 4 s exposure with the aid of a
cable release.
Note! Some films may display a loss of sensi-
tivity (reciprocity failure) at very long expo-
sures. Any exposure compensation necessary
will be indicated on the data sheet supplied
with the film.
Focusing (Fig. 64)
The distance is set with the focusing ring (2).
The ring is turned until the subject is as sharp
as possible on the focusing screen. “Rock”
the ring back and forth past the point of ap-
parent sharpest focus before you stop. This
will make it easier to ensure that the lens is fo-
cused properly. The distance from the subject
to the film plane is read off on the distance
scale (10) opposite the central index (12).