Quote Originally Posted by Big Bad Wulff View Post
The only thing that needs to be focused is anything from 20 ft on in. If you are taking a photo of anything past 20 feet and the focus is set at infinity, there is no need for the camera to focus. Thus turning it off for distant photos should elicit faster shutter reaction time.

20 feet and beyond is "opitcal infinity".

Bill, the eye doc and too many optical physics courses later......................................
Big Bad Wolf ..........
"Optical infinity" would also depend on the f-stop used.
It could be as low as inches to infinity if a high enough f-stop was used. Not just twenty feet.
DickM.