ORIGINAL: buckeyebuckhntr
I would go with the latter.... Pick a day with a storm or cold front maybe even a day the wind shifts completely different than the previous day(s).
IMO.... Easier said than done when you know you are getting the traffic though
Kind along the lines of what i was going to say...
I would pay attention to the wind direction in the morning of the day your gettin the pictures. A lot of time this dictates where they bed, therefore where they will come from to feed. You might see a pattern there.
If still they are coming at completely random times then, like buckeye said, get in there right before or aftera front.