What do you do for zooms, adjust for the mid point.?? Dave
On Fri, Feb 25, 2011 at 7:02 AM, Paul Stenquist <[email protected]> wrote: > > On Feb 25, 2011, at 6:42 AM, Boris Liberman wrote: > >> On 2/25/2011 1:36 PM, Krisjanis Linkevics wrote: >>> What is Paul's system? :) >>> I haven't adjusted any of my lenses ever but maybe I should so if there is >>> a "better" way I want to know! >>> >>> kris >> >> I am certain Paul will give you a full answer. Here is mine, kind of second >> hand. Paul has made a target which I think he can share. You put it on the >> floor, you shoot it with your camera angled approximately 45 deg to the >> floor and once you shoot you correct the AF with in-camera correction >> module. By doing so you "dial in" or effectively produce an individual >> correction for each of your lenses, provided you don't have too many. In >> case of fast or "cranky" lenses, such as FA 50/1.4 or zoom lenses such as >> Sigma 24-60/2.8 (Sigmas generally being known for AF imprecision) it can be >> a difference between lost and made shot. >> >> Now, since they are offering prices to good fathers, I also dialed in >> specifically Galia's lenses for K-7. FA 50/1.4 needed minor correction, DA >> 21 and FA 100/3.5 did not. >> > > It's not really my system. It's pretty much the standard for adjusting > autofocus, and Boris has it right. There are alternatives that are somewhat > easier to use but more difficult to construct, such as a method where the > target is a slope that rises at 45 degrees and the camera is level. The > target, whether on the floor or angled up from the floor has a series of > evenly spaced line and a central target line. I made my target line slightly > bolder than the rest and placed a red dot at its center. After shooting in > single center spot autofocus mode, with the center line as the target, you > simply observe the results and determine if the center line is indeed the > sharpest. If not, you can see if the camera is back-focusing or > front-focusing by determining which line is sharpest. The important part is > that you shoot of a tripod when adjusting and check the focus at wide open > apertures. I also check my results on the computer screen rather than trying > to decipher a tiny image on the camera viewing screen. > Paul > > >> Boris >> >> >> -- >> 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. > > > -- > 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.
