When you are using a speedlight (such as a Nikon SB-800, say, or a Canon 430EX) and firing it in manual mode by using a Pocketwizard, there is one problem I see a lot.
Namely: after a few minutes, the speedlight turns off. It times out, “goes to sleep”, and the flash stops responding until you wake it up again. Grrr!
The solution: use a custom function on the flash to disable the timeout. When you have successfully done this, on a Nikon, you will see the timeout words followed by “—“. On a Canon, you will at least see an indication that a custom function has been activated, by the “C.Fn” symbol on the back of the flash:
See, bottom left of the display. (It’s usually custom function 1: check your manual).
Yes, I know – the interfaces used to operate your flash are terrible. Press this button, go right, hold down that button, sing incantations while dancing around an oak tree, then enter the square root of pi: not for the fainthearted. But worth learning!