I didn't say they weren't mindless... Paul Stenquist wrote: > No? Read more. Those who act without thinking are zombies as far as > I'm concerned. Now, there are some very intelligent and interesting > photographers on all of the forums. But the forum structure seems to > attract the mindless few as well. And it seems just a few zombies can > cause enough fear to generate mass hysteria. > On May 6, 2008, at 9:06 AM, P. J. Alling wrote: > >> I wouldn't call them zombies... >> >> Paul Stenquist wrote: >> >>> I suspect that back and front focus problems are almost always the >>> fault of the camera. I too have noticed the hysteria on the Pentax >>> forum. It's the result of some real problems that have now caused >>> paranoia and a search for problems where none exist. Some DA* 16-50 >>> lenses had a manufacturing defect that caused an uneven focal plane. >>> In other words, the right side of the frame might be in focus, while >>> the left side was not. This was a lens problem, but it seems to have >>> been relatively rare and confined to early samples. However, a second >>> condition has complicated the situation. It seems that early K10D >>> cameras were not properly set up for USM, and the firmware update >>> didn't do the job. These cameras backfocused with the USM lenses. >>> But it's apparently a simple fix, and it's not a lens problem. >>> However, the mindless zombies on some forums have blown all of this >>> way out of proportion. As you say, they test every lens, usually >>> handheld and in questionable conditions, and curse and complain. It's >>> an ugly situation, although brought on in part by some problems >>> Pentax created. >>> Paul >>> On May 6, 2008, at 7:30 AM, Andreas Pfotenhauer wrote: >>> >>> >>>> hi, >>>> >>>> i recently followed a discussion in my favorite forum (bulletin >>>> board?) >>>> where a guy who had bought a DA 35/2.8 Limited was very disappointed >>>> because he found the *lens* to have severe back focus on his K10D >>>> while >>>> on his K20D it seemed to work just fine. >>>> >>>> As far as i understand it (with my limited optical knowledge), a >>>> lens >>>> can (and does) produce various forms ob optical aberrations, but if >>>> the >>>> "virtual image" is not directly on the sensor but in front or >>>> behind, >>>> then it's simply not properly focused, isn't it?! So the AF of the >>>> camera would be to blame for not acting accurate or, as second >>>> possibility, sensor, AF sensor and/or focusing screen are not >>>> leveled. >>>> I was asking if someone with a deeper understanding of the optics >>>> could >>>> confirm or denial this, but no one was able (or wanted) to, thats >>>> why >>>> I'm asking here now :-) >>>> >>>> The reason why I'm so interested in this is: a increasing number of >>>> ppl >>>> in that forum now test their newly bought lenses with a printed test >>>> chart under more or less undefined light conditions, of course they >>>> find >>>> some back- or front focus (of you look hard enough you surely find >>>> something to worry about, I'm 100% convinced), and then they send >>>> their >>>> lenses back, open new threads in the forum where they loudly >>>> complain >>>> about lens qualities, unsettle some more who start testing their >>>> lenses >>>> ... you get the drift. >>>> >>>> I would be deeply grateful if someone could shed a light on this, so >>>> this can be settled once and for all. >>>> >>>> Free beer is offered if that one will ever visit Frankfurt, >>>> Germany ;-) >>>> >>>> cheers >>>> Andreas >>>> >>>> >>>> -- >>>> 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. >>>> >>>> >>> >>> >> -- >> Vote for Cthulhu. Why settle for a lesser evil... >> -- Dr. Jerry Pournelle >> >> >> -- >> 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. >> > > >
-- Vote for Cthulhu. Why settle for a lesser evil... -- Dr. Jerry Pournelle -- 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.
