Diaphragm Setting - BOLEX H16 SBM Instruction Manual

Diaphragm setting
The lens diaphragm controls the amount of light
reaching the film and is adjusted according to the
lighting conditions, the film sensitivity, the filming
speed and the position of the variable shutter. The
amount of light admitted by the diaphragm is doubled
at each successive setting, starting from the highest
figure. For instance, moving the diaphragm setting
from f/11 to f/S doubles the amount of light passing
through the lens.
The Bolex exposure meter
was designed and cali-
brated especially for your camera and allows for the fact
that about 25% ofthe light
IS
detiected mto the vlewfinder-
by the ·retiex prism.
i
he exposure meter fits on to a
special shoe (see page 6).
The use of the exposure meter
safeguards against
exposure errors. In the chart opposite, the figures listed
in the column under "adapted exposure times" take
into account the light deflected by the reflex prism.
12
-.
Exposure times (in fractions of a second)
Adapted
1/40
1/55
1/60
-
12 f.p.s.
16 f.p.s.
18 f.p.s.
Real
1
1/33
1/45
I
1/50
24 f.n.s.
1
1
/
65
1/80
-
1
1/90 1/112
1
1/150 1/188
1/90
1/130
1/180
1/110
1/160
1/220
32 f.p.s.
48 f.p.s.
64 f.p.s.
Speed
I
Single-frame
I
~~ntrol knob
1
exposure
18-64 f.p.s. 1/30 1/40
(selector in position T