Mamiya 645 PRO TL - Manual (Page 32)

Flash Photography
In addition to its standard flash sync system, the Mamiya
645 PRO TL features TTL (through the lens), off the film
electronic flash exposure automation. A flash
sensor located inside the camera body reads the flash
reflected from the film surface at the moment of exposure.
The is connected via coilcords to a dedicated
electronic SCA 396 thyristor module, which is
attached to the flash shoe of the camera. The module has
an dial on which the speed of the film in use is set. The
resulting flash exposure automation determines correct
flash exposure and automatically adjusts the output of the
flash. It also automatically corrects for exposure
compensation ordinarily required when using filters, close-
up bellows extension tubes. However, as all TTL
systems, it requires manual compensation
for differences
in film surface reflection characteristics. Compensation is
made by adjusting the film speed selector
setting an SCA
396 module. The amount of compensation is determined
by experimentation.
Important:
Read Operating Instructions which are supplied with
flash unit before use.
Always turn off camera’s
power switch when attaching
or removing flash units.