Canon 199 A - Manual (Page 35)

For viewfinder displays when the 199A is
set for Manual control, see pages 27 and
28.
In the case of manual operation in flash
photography, i.e. disengagement of auto
flash mode, the camera will not automat­
ically revert to the without-flash AE mode
between the lighting of the pilot lamp,
except when using the AL-1, AV-1 and
New F-1 (the latter arranged to provide
aperture-priority mode).
For your easy reference, the following is
the formula used for obtaining the f/stop:
f/stop to be obtained =£uidenumber---------
shooting distance
However, attention should be given as to
whether you are working in feet or meters.
30 (in meters) for ISO/ASA 100 is the
guide number for the 199A.
The guide number changes according to the
film speed. The calculator dial on the 199A
automatically changes the reading for a
change in the film speed setting on the dial.
The user takes flash photography in manual
mode (setting aperture selector switch at
the back to M) when the photographic
situation does not prompt automatic flash
exposures, when shooting at close range or
for special picture composition purpose.
When performing flash photography with
the flash unit unmounted from the camera,
use the flash unit-to-subject distance
instead of the camera-to-subject distance
on the distance scale of the lens in deter­
mining the f/stop.
35