Canon DS-8 - Manual (Page 32)

Exposure Control by Variable Shutter
Variable Shutter Control Lever
By sliding the variable shutter control lever, the open angle of the
shutter leaves changes and the exposure volume can be adjusted at
four stages.
To change the position of the variable shutter control lever, slide
it upwards and shift to the desired position. Slide the lever down­
wards so as to fix its position.
Each stage of the scale is at a position which halves the open angle
of the shutter. Thus, the open angle degree of each scale is as follows:
“OPEN” “2” "4“ “CLOSE"
165° 82.5° 41.25° 0°
(Completely opened) (Completely closed)
■ By sliding the lever to the “S” position, film advance will be locked
and the shutter will not function.
Variable Shutter Angle and Filming Speed
Changing the variable shutter control lever will relatively affect the
filming speed and exposure time (in seconds) as follows:
Scale
Open
Angle
12 fps 18 fps 24 fps 36 fps 54 fps
"OPEN" 165" 1/26 1/39 1/52 1/79 1/118
"2" 82.5“ 1/52 1/79 1/104 1/158 1/236
-4-
41.25” 1/104 1/158 1/208 1/316 1/472
"CLOSE” 0“ - - - - -
Film Speed Adjustment
When the position of the variable shutter control lever is changed,
film speed setting should be adjusted to compensate the exposure
factor.
Match the film speed with the proper exposure factor mark which
is the same as the open angle index being used. For example, when
the variable shutter control lever is set at “2“, and the speed of the
film being used is ASA 25, set the scale of “25“ at the orange index
“
2
” .