Canon 155 A - Manual (Page 2)

The Canon Speedlite 155A is an automatic
electronic flash developed especially for AE
flash photography with the C&non AE-1.
It also makes AE flash photography possible
with the A-1 and serves as an ordinary com­
puter flash with the Canon AT-1, AV-1 and
other cameras. When the A-1 or AE-1 is
set for automatic exposure photography and
the pilot lamp lights up, the epoch-making
system of the 155A functions to automati­
cally adjust the camera’s shutter speed to the
X synchronization speed as well as the aper­
ture to the prescribed aperture. The ex­
posure is automatically determined by the
amount of light reflected back from the sub-
ject.This flash employs a unique averaged
light sensing system which reduces excessive
reflection from the central area to give better
overall exposure. Thus, the 155A offers