For what its worth.... I have been using cameras for about 3-4 seasons now in my pre and post season scouting. The reason I use the cameras , more or less anyway, is to see what deer are using my hunting area. In a way i agree with shed...i cant take the chance of spooking a deer at my stands, so i dont set them there.
First...I know we have all had the pics of a deer with its nose in the camera. This to me means that the idea that the flash appears to be lightning to a deer, is false. If it appeared to be lightning it would not pay attention and move on... but instead they investigate the source...Im sure they know that lightning doesnt come from a tree.
Second... I have set my cameras on runs in the winter with snow on the ground...deer will just begin to avoid the camera...they dont stop using the whole area...they just dont walk past the camera.
I usually set my camera in feeding area's...this lets me see the deer that are in my area without alerting them to exactly where my stands are. For example I usually hunt a ridge back in off some fields (corn and alfalfa). By putting the cams in the fields I see the deer that are in the area without spooking them out of the funnels I hunt them in.
I hunt with my brother and for two years going now we a have takin quality bucks that we did get pics of before the season a 10pt 140, 8 pt 125, and a 7 pt 120 (in MA those are quality and to do this with frequency is a rareity). The 7 point we actually had never got a pic of, but he came through just like the others. What the cameras have done is given us a reason to let the spikes and forks pass by. We now know we have quality deer in the area, and we are able to wait and sit the extra hour or two...and its fun to see the deer you have had pics of.
So for what its worth in short...deer do see the cams...i think they will avoid them... but it does not scare them out of the area.

hope it helps...