The only things that matter for good camera technique in porn:

1) Focus
2) Good uniform lighting
3) Seeing both the slut's ass being penetrated and the pained/"where's my paycheck" expression on her face in the same shot.

Bonus -- sound: Keep sound at a constant level. The absurdity of volume level going up and down depending on how close the camera guy is to the action has got to stop. Get some mope off the street to hold the boom for you for free with the promise of seeing sex really up close. Tell him he gets a BJ from the starlet if the the boom never sinks into the shot frame -- guaranteed you'll never have to deliver, but should be enough of a motivator to keep the frame clean most of the time.