Canon AE-1 - Manual (Page 64)

Canon Speedlite 155A
The versatile circuitry ot the Car>on AE*1
allows it to perform fully automatic flash
photography with the Speedlite 155A es
pecially designed for this camera. It is not
necessary to set the shutter speed or the
aperture on the camera as, up to now, flash
photography required.
When the 155A is attached to the AE-1.
set the aperture ring of the lens to the "A"
mark and the shutter speed dial to any
position other than "8*' (Bulb). With the pilot
lamp of the 155A lighting up, the 155A func­
tions to automatically adjust the camera's
shutter speed to the X synchroniaation speed
as well as the aperture to the prescribed
t/stop value.
After It flashes, the camera automatically
switches over to the AE photography mode
until the pilot lamp lights up again durir>g
which period AE photography can be con­
tinued. A steady support may be required if
shutter speeds art slower than 1/30 of a
second.
Like ordinary flash units, you can also
perform flash photography by operating the
aperture ring nvanuallv. When you are using a
-r r.
Carton EL lens which does r>oi allow full
aperture metering, automatic flash photo
graphy can
b o performed by settirig the
prescribed f/stop on the lefts manually. In
both cases, the shutter speed is automatically
adjusted to the X synchronisation speed of
1/60 sec.
This flash employs a unique light sensing
system, so excessive reflection from the
central area is reduced giving better overall
exposure.
Moreover, when the main wvitch of the
bpeedlite 1S6A is turrted off, the llvsh cir­
cuitry is completely cut off and the Ab-1
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