I know one thing, the smaller the lens element, the better machining tolerances you need to center it properly. Think about it, if the barrel is big enough for the element to fit into it then there is some "slop" involved no matter what.
If I were you I would get some real fine grain FILM like tech pan or TMAX 100 and do some tests using a tripod. Shoot both film and digital SLR and compare. If the images are equally soft on both then there is something wrong with the lens because it should be able to exceed the resolution of the DSLR and that would be detectable with the very fine grain film which has higher resolution than the DSLR will permit. JCO -----Original Message----- From: Alan Chan [mailto:[EMAIL PROTECTED] Sent: Sunday, August 22, 2004 5:03 PM To: [EMAIL PROTECTED] Subject: Re: 15/3.5 sharpness? Could be, but I have no way to tell. Axis alignment is virtually fixed and determined by the accuracy of the machining, as with most Pentax manual focus primes. The glass to glass distances may be altered when they were being reassembled. But then again, there is only one way to screw them in (till stop). If they are manufactured accurately, they should be again when reassembled. Perhaps they have some instruments to measure individual glass to glass distance in the factory, that I do not know (if possible at all)? Anyone know anything about this? Alan Chan http://www.pbase.com/wlachan >No, they don't. They look like the pictures I took with my A15/3.5 on >the *ist D. Pictures I took on film (usually shot on color slides such >as the Sensia 100) with the same lens were far better. On film, all >apertures f/5.6 to f/11 are more than useable, while I tried to avoid >shooting at f/3.5, f/4, f/16 and f/22 because of noticeably lesser >sharpness. I don't know which is the weak ring in your chain, but the >15/3.5 can deliver better sharpness for sure. I've been told the 15mm >(all 15mm lenses, not the Pentax) to be very critical about alignment >of optical elements. Can this be the possible reason for its poor >performance? > >Dario Bonazza _________________________________________________________________ MSNR Calendar keeps you organized and takes the effort out of scheduling get-togethers. http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU =http://hotmail.com/enca&HL=Market_MSNIS_Taglines Start enjoying all the benefits of MSNR Premium right now and get the first two months FREE*.
