Taken from the *istD manual page 74: " The camera switches to predictive AF mode automatically when a moving subject is detected in AF.C (Continous mode). "
Frits Wüthrich On Wednesday 27 December 2006 22:36, Jens Bladt wrote: > No, I doubt that this camera does feature predictive AF - it doesn't really > track or calculate anything AFAIK. Predictive AF means calculating where > the subject will be at the actual time of release - using calculations > based on the pattern that a moving object describes on the focus screen. > The *ist D does not do such calculations, does it? It's not exactly F16 > weapons technolgy :-) > > Even if it did, it wouldn't work well when the object is moving very > directly towards the camera - then there is only VERY little movement to > calculate (the movement caused by the subject changing it's size as it's > getting closer or farther away). All it does is focus on what ever is > close or has high contrast. It's really just a focus trap - that is always > a little bit too late. > > Secondly I never let the camera choose the AF point. I always use the point > in the middle. So, this can't be the reason for my shots beeing unsharp > either. The only reason I can think of is that it doesn't focus properly on > moving objects, because it's too slow. When ever the red square appears, > the object is allready out of focus again, before the shutter fires. > > The K10D and the *ist D does have the same generation AF system, according > to dpreview; the SAFOX VIII. > I have never heard or read anywhere, that this system had predictive > autofocus. > > The PZ-1 was said to have this (according the the user manual - which says > about SERVO mode: "The predictive autofocus function is effective in this > mode"). But I seriously doubt that the camera computer actaully did such > focus calculations or really is very predictive. > > Even if they have just NAMED the servo mode/continuos mode "predictable > autofucus" - it's still not very fast, is it? > > Regards > Jens Bladt > http://www.jensbladt.dk > +45 56 63 77 11 > +45 23 43 85 77 > Skype: jensbladt248 > > -----Oprindelig meddelelse----- > Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] vegne af John > Francis > Sendt: 27. december 2006 21:12 > Til: Pentax-Discuss Mail List > Emne: Re: *istD AF > > On Wed, Dec 27, 2006 at 04:47:49PM +0100, Jens Bladt wrote: > > Very nice photograph - in fact it's excellent! > > This was not done with continous AF, was it? Well, at some distance any > > photograph is always sharp. Only not necessarily where you wnat it to be. > > In my experience the *istD AF/Continuos AF is not fast enough for > > anything movuing faster than a walking human. I have pointed this out > > many times on this list. Other list members allways seem to answer me, > > that shots like this must be done using MF. > > That's a misrepresentation of the history. When you've posted examples > in the past, it's often been pointed out to you that the problem lies with > the selection of the auto-focus point. The camera is quite capable of > tracking moving objects at speeds well in excess of humans walking (as > photographs from myself and Doug Franklin, amongst others, demonstrate). > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.409 / Virus Database: 268.15.28/604 - Release Date: 12/26/2006 > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.409 / Virus Database: 268.15.28/604 - Release Date: 12/26/2006 -- -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
