How to Take Action Shots
If you want to take action shots, you have to get fancy with the console.
The game doesn't ordinarily allow you to view your character from any angle other than from behind when you have a weapon drawn. This can make it difficult to get a good action shot. (Other than by pressing PrtSc when a fatality cut-scene plays, of course.)
You can get around this by opening the console and typing
then close the console by pressing the '~' again.
tfc stands for 'toggle free cam' and allows you to detach the camera from its usual position and move it around a scene using the movement keys (WASD). While the free cam is active, the action will stop and you can spend as much time as you like lining up the perfect shot. When you have the shot lined up, just use the normal methods of taking a screenshot.
When you're done with your shot, open the console again and type
to return the camera to its normal position.
You can combine the free cam with the no HUD option and take action shots without any HUD elements as well. Just type 'tm' after 'tfc 1'. The console will disappear, so remember to type '~' again after typing these commands to get back