AGFA 307 Owner's Manual page 61

P.C. Terminal
The digital camera's threaded PC terminal accepts PC type sync. cords
from non-dedicated flash units, or flash units that do not have a hot
shoe connector. When you connect a sync. cord to the PC terminal,
set the shutter speed to 1/90 sec. or slower. Manually set the white
balance to the flash mode.
Certain Studio Flash Systems operate on a Negative Polarity triggering
system (See below).
It is possible that when using a system of this nature in conjunction
with the ACTIONCAM the flash may not fire.
It is therefore recommended that before using a Studio Flash system of
this nature you contact an AGFA Dealer for advice.
Positive Polarity Negative Polarity
• The trigger voltage of some flash units may be too high for the
digital camera to fire the flash. If this is true of your flash, contact an
authorized AGFA Dealer.