I like to place my cameras about 6 or 7 foot high. They do seem to pass it off as lightning more often. Doesn't seem to spook them like a flash in the face. I do think it all depends on the personality too. Some deer don't care, others will only let it happen once. Like Goose said, it just seems to alter their path a little.
That said, i don't like IR pictures that well. I like the better quality photos.