Any difference must be due to AF innacuracy, shutter lag or a wrong prediction being masked by the DOF. IF the AF SPEED was not good enough then the shutter would not have fired as it would not have achieved FOCUS WIDE OPEN. The shot taken at F11 was still focussed as far as the camera was concerned before the aperture blades were closed - ie at f2.8.
> -----Original Message----- > From: Bruce Rubenstein [mailto:[EMAIL PROTECTED]] > Sent: 11 March 2002 14:45 > To: [EMAIL PROTECTED] > Subject: RE: AF speed (was: Silly Photo.net thread) > > > Take a f2.8 telephoto lens, shoot a quick moving subject at > f2.8 and f11 and > see what the percentage of in focus shoots you get at both > apertures. If > they're both %100, find a more difficult subject. If they're > both 0% find an > easier subject. I already know the answer, because I've done it. > > > --- Rob Brigham <[EMAIL PROTECTED]> wrote: > > But DOF is not an issue for focussing - the camera focusses > wide open. > > It doesnt stop down until you take the shot. When you talk > about the > > subject leaving the plane of focus before the shutter fires this is > > shutter lag. Lens performance aside, the camer always gets > the subject > > in focus at f2.8 if it is an f2.8 lens. > Try FREE Yahoo! Mail - the world's greatest free email! > http://mail.yahoo.com/ > - > This message is from the Pentax-Discuss Mail List. To unsubscribe, > go to http://www.pdml.net and follow the directions. Don't forget to > visit the Pentax Users' Gallery at http://pug.komkon.org . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
