On Feb 25, 2011, at 10:36 AM, David J Brooks wrote: > What do you do for zooms, adjust for the mid point.??
Yes, but I usually check both ends of the range as well, just so I know what I'm dealing with. I re-checked the DA* 50-135 the other day, and it was right on in all three positions. Paul > > Dave > > On Fri, Feb 25, 2011 at 7:02 AM, Paul Stenquist <pnstenqu...@comcast.net> > 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 >>> PDML@pdml.net >>> 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 >> PDML@pdml.net >> 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 > PDML@pdml.net > 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 PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
