How to debug my webcam problems? I'm quite a new OS X user and come from a linux background - usually to debug my problems I consult the logs as per /var/log/syslog however with Yosemite i'm not sure what i'm looking for.

Any way my problem is that I will load Skype and video call someone which works fine but the moment my mac is locked or goes into hibernation mode the next time I try video call the web cam is not detected - if i attempt to use Photo Booth this too doesn't detect a webcam.  Some google searches has revealed it's a conflict where the camera is "in use" when it isn't - and other articles seem to point towards AirParrot which i do not have installed.


How would I determine where the fault is?
How do I then resolve this fault?


Rebooting does seem to be a solution but IMO theres a bug that needs fixing because rebooting to get a cam to work is just simply absurd - even Windows can function more reliably.
As commented by @aglasser to fix the Cam not working simply:


Open Terminal.app; and
Run: sudo killall VDCAssistant


In order to resolve another similar issue with the built-in Microphone:


Open Terminal.app; and
Run: sudo killall coreaudio