OK, I simply have to ask what the point of flying is for you.
A camera is hardly required equipment. It should be the FIRST thing jettisoned.
Aviate, navigate, communicate, and then
consider nonessentials only if the workload is far from saturated. This is not the case during run-up, nor during or right before a takeoff. The point of a run-up is to find problems with your aircraft, not to go through a ritual. This is your last chance to spot a problem that might kill you.
This is very much like the usual sterile cockpit procedures. Discuss and even
think only about things related to flight.
I don't want to hear that you got your camera working, but crashed the aircraft. Ever.
Watch this video and see if you can spot the configuration error. Hint: he's at a high altitude field. You can see it in the first 15 seconds, but only very briefly.
http://www.liveleak.com/view?i=835_1344412426