best camera angles I can think of:
squat: from a 45 degree angle to the rear, inline with the opposite leg.
example.
This angle allows us to see most of the important things: bar position, grip, elbows, depth, and knees. It's definitely the best angle to check for knee cave.
bench: I'm really not sure. I'm guessing from the side.
deadlift: either the side or from an angle (either front or back). I prefer an angle from the front:
me from 45 degrees to the front.
This angle has the advantage of seeing your stance and you still get a good view of the back angle and hip movement. Of course, direct side angles can be used to check on a specific issue.
press - from the side is good for checking the bar path, though big-boy plates can obscure the view. An angled view from the front allows us to still see the the bar path pretty good while also checking grip width and wrist bend.
This is a really good press angle:
Miles
oly stuff - not sure.
I think in general, an angled view from the front or back (depending on the lift) gives you the most bang for your buck. Specific views can be used to look at specific things.