What kind of light was illuminating your subject? How contrasty was it? Try AF outdoors.
When working correctly on the K20D, SDM can focus in something like 0.2 seconds. But in reduced light you can count on many seconds -- while the smile fades from your portrait subject ... This all improves quite noticeably on the K-3. But really low light still causes problems that I solve by switching to MF. On Wed, Mar 19, 2014 at 6:43 PM, David J Brooks <[email protected]> wrote: > Could be, i mostly tried it at 650-70 length. It was and i', m not > exagerating at least 2-3 if not more seconds to focus. You could see > it in th efinder getting closer and closer and hey there ist in focus. > Not sure i want something i need to just hold and hope. > > Dave > > On Wed, Mar 19, 2014 at 6:31 PM, Dario Bonazza > <[email protected]> wrote: >> Well, the DA* 50-135mm SDM is probably the slowest AF lens on Earth, gaining >> it the nickname of "the sloth". Generally speaking, SDM lenses are slower >> than both screw-driven ad DC Pentax AF lenses, so the DA 17-70mm is a good >> candidate for being another slow-AF lens. However, I own it and I don't find >> it THAT slow as you pointed out. >> There is however another problem I saw on several samples of that lens and >> is the almost impossibility to autofocus above 50mm focal length, hunting >> forever while you try & find the focus. Perhaps that's the problem you >> spotted. >> >> Dario >> >> -----Messaggio originale----- From: David J Brooks >> Sent: Wednesday, March 19, 2014 11:17 PM >> To: Pentax Discuss >> Subject: Pentax 17-70 f4 and SDM motor question >> >> >> Hi all >> >> I went to pick up above mentioned lens this afternoon. loks and feel >> nice on the K-5, however me thinks there is a problem. >> I know the AF of Canon and Nikon are quite fast leaving us Pentaxians >> hunting and pecking our way through landscapes and soccer photos, BUT, >> 2-3 seconds to lock on and focus on a static object.?? Me thinks >> that's a bit to slow. >> The salesman and i played with it for 10-15 minutes. It did get a tad >> faster to focus but it was still painfully slow. I know it will not be >> as snappy as my Nikon 70-200 f2,9 VR lens, you can barely hear >> anything and it locks on faster than Mike Johnson deleting a cat >> photo. >> >> So, am i missing something with this SDM system. Is it painfully slow >> or should it be as fast or faster to AF on a subject as the screw >> focus lenses. Do i need to adjust a menu setting or something. >> >> Another is on order for Saturday >> >> Dave >> >> -- >> Documenting Life in Rural Ontario. >> www.caughtinmotion.com >> http://brooksinthecountry.blogspot.com/ >> York Region, Ontario, Canada >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. >> >> >> ----- >> Nessun virus nel messaggio. >> Controllato da AVG - www.avg.com >> Versione: 2013.0.3462 / Database dei virus: 3722/7216 - Data di rilascio: >> 19/03/2014 >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > > -- > Documenting Life in Rural Ontario. > www.caughtinmotion.com > http://brooksinthecountry.blogspot.com/ > York Region, Ontario, Canada > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- -bmw -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
