FORGETTING MEMORY CARDS. Forgetting to set the f/stop properly. Allowing the shutter speed to exceed the X-synch speed limit. Forgetting to verify flash power level. Failure to charge or install fresh batteries. Failure to re-set the ISO for "today's" conditions, and leaving them at "last night's" value. Wrong white balance. Dirty lens. Failing to focus properly. Misplacing the tripod plate. Knocking the tripod over. Allowing a lens hood to fall off a cliff. Allowing a lens to fall off of the camera body. Trying to force a shot when the damned ON/OFF switch is set to OFF. Metering with the camera set to "the wrong mode", and getting totally whacked exposures. Using the WRONG lens hood, and getting undesired vignetting. I think these are the most common blunders.
Ouch. The truth hurts.
I have absolutely NO idea where my stupid tripod plate is right now. :lmao:
I know about 2,547 places where it is NOT, however.
I'm SOO careful with all my other photo gear--why can't I be more careful with that little plate??