3DR X8 LOG_BITMASK question

I have a 3DR X8 built form components only for mapping.
Flies OK but problem is that I cannot use the logs as they are not containing any CAM lines.
As the outputs 1-8 are occupied by the ESCs I put the Camera trigger on RC9
Can somebody tell me what will LOG_BITMASK number should I use or how to moidify the connections to have CAM line in the log
-1 and 397310 I are already tried without luck.

Any one any idea? I am getting pretty desperate…