(That's an analogy from a quaint analog device called a tape recorder. When everything is digital, will we use digalogies instead of analogies?)
Anyway... My recollection was that the autofocused and manually focused images were sharp in the finder but blurry on film. Thus, the focusing screen and the AF sensor agree with each other, but disagree with the imaging sensor. This would indicate that the imaging sensor needs shimming, not the focusing screen. Or, to do it the hard way, one could shim both the AF sensor and the focusing screen to get them to agree with the imaging sensor. In any case, it would seem that the camera needs to take a trip to a Pentax facility. Rick --- Godfrey DiGiorgi <[EMAIL PROTECTED]> wrote: > A friend of mine had a similar issue with his Canon > 10D. His > manually focused exposures were never quite on the > money, but AF > exposures were bang on target. After a suitable and > similar > round of measurebating, he concluded that the > focusing screen > was in need of shimming ... It was representing a > focus plane > some small fraction of a millimeter off from where > the sensor > was. Autofocus worked fine because it evaluates > focusing > distance through a completely different set of > optics and > parameters than manual focus. > > He had his camera adjusted by Canon and now it > focuses > precisely, both in MF and AF. I believe they shimmed > the > focusing screen. > > Godfrey > > --- "Gonz" wrote: > > I need some help with my *istD. For the longest > time, I've > been > > having problems with my pics being quite soft wide > open. I > > thought that it was just because the lens was wide > open. I > have > > alot of manual focus lenses, which I use often. > The problem > > showed up mainly with them, so I went back to look > at some of > the > > pics more carefully, and I noticed a pretty > consistent > pattern. > > There were areas of sharpness alright, but not > where I wanted > > them to be. I was consistently back-focusing. So > I did some > > tests. I mounted my FA* 85 1.4 on the camera, set > it on a > > tripod, and proceded to make some careful > experiments to see > if I > > could put the blame where it belonged, on me or > the camera. > > > > The setup was your typical measurebating focus > test setup. I > had > > a ruler at an angle with a target off to the side > of it where > I > > focused. I took pictures with and without > autofocus. The > result: > > no matter how carefully I manually focused, the > autofocus was > > always right on the money, and I always back > focused. I > adjusted > > the diopter after autofocusing to see if I could > match the > > camera's focus point, took my glasses off, put my > glasses on, > > danced around the camera, but no matter, I always > back-focused. > > What is going on here? Doesnt the autofocus see > the same > thing I > > do? Or is something mal-adjusted somewhere? When > I look > through > > the viewfinder after I auto focus, it seems to be > in decent > > focus, but it looks pretty much the same as when I > focus > > manually. If I then switch to manual focus and > get it out of > > focus and back in and take the pic, it is > back-focused! Am I > > going blind? ... > > > > > > __________________________________ > Do you Yahoo!? > Yahoo! Sports - Sign up for Fantasy Baseball. > http://baseball.fantasysports.yahoo.com/ > > __________________________________ Do you Yahoo!? Yahoo! Mail - now with 250MB free storage. Learn more. http://info.mail.yahoo.com/mail_250
