>I'd love to be around on the day they invent a camera you can point at the >centre forward at the beginning of a soccer game, give you focus >confirmation and then stay focused on the guy for the rest of that half. I >suppose true locking will require some kind of 3D focusing system combined >with computerized optical recognition.
I guess it would be even better if the camera could just stay focused on the ball! :-) Jens mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -----Oprindelig meddelelse----- Fra: Jens Bladt [mailto:[EMAIL PROTECTED] Sendt: 16. januar 2005 09:21 Til: [email protected] Emne: RE: *istD AF performance (was Re: Sigma 2.8 Zoom lens comments) Yes. ...what they all will say, in order to sell. Don't believe everything you read in an ad! I guess tracking describes the currently available AF functions better than locking. What they mean by locking is simply "focus" or "obtain focus confirmation". But focus confirmation just indicates that "something" is in focus. Tracking might be close to what Minolta called "predictable auto focus" when the Dynaxes were introduced. The camera can predict a (single) subjects movement across the "screen" to determine the place where it will be, at the real time of the release. Since the introduction of multiple focus points, I haven't seen "predictable AF" in the ads anymore. Pentax PZ-1 had a similar description (predictable AF in Continuous mode) in its user manual. Today this is just called continuous focus "C". "C" jsut means the camera will try to refocus whenever the subject gets out of focus. It will then perhaps focus onsomthning else - perhaps the next guy in a line. I don't know they ("C") can actually predict anything anymore. In my world (Pentax) there's just Single and Continuous. And then there's the automatic selection of focusing point. This simply means "multiple sigle" or "multiple continuous". These features will allow the camera to focus on just about anything. I suppose that's quite the opposite of locking on to a (single) subject. I'd love to be around on the day they invent a camera you can point at the centre forward at the beginning of a soccer game, give you focus confirmation and then stay focused on the guy for the rest of that half. I suppose true locking will require some kind of 3D focusing system combined with computerized optical recognition. Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -----Oprindelig meddelelse----- Fra: Herb Chong [mailto:[EMAIL PROTECTED] Sendt: 16. januar 2005 00:53 Til: [email protected] Emne: Re: *istD AF performance (was Re: Sigma 2.8 Zoom lens comments) tracking and locking are the same thing in most manufacturer's literature. Herb.... ----- Original Message ----- From: "Jens Bladt" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, January 15, 2005 6:43 PM Subject: RE: *istD AF performance (was Re: Sigma 2.8 Zoom lens comments) > About locking onto something: To me this means focusing on a subject, then > stay focused at the same subject, even if it moves. No camera that I know of > does this. Not even the Canon D1. Cameras loose focus when things move, but > may refocus at the same subject after a while. Or it may focus on something > else! That's not locking onto a subject, is it? Tracking perhaps, but > certainly not locking.
