----- Original Message ----- From: "Paul Stenquist" Subject: more K20D autofocus adjustment results
> So far I've adjusted the FA 50/1.4, the FA 35/2 and now the DA > 16-45/4. The 50/1.4 came in at -4. I retested to make sure. Same > result: -4. The FA 35/2 came in at +2. Tonight I did the DA 16-45/4, > and as I suspected, it was closer to dead on at just +1 adjustment. > > I simply do a series of shots of crisp typography off the tripod, > wide open (or just slightly stopped down) at seven or more adjustment > values. I use single point, center autofocus. I convert each shot to > a full-res 16-bit file, line them up on the monitor, then pick the > sharpest one, based on the letter where the center point autofocus > fell. It's easy to see the sharpest at 200% of full resolution. I can > check a lens in about fifteen minutes. > > I like this feature. But the lens-to-lens variation I'm seeing also > explains why Pentax went to this lens-specific adjustment. I'll bet > that in trying to address the complaints of K10D owners they realized > that adjusting focal point for one lens didn't necessarily make the > camera correct for every lens. I think we have a very good thing here. I did a Q&D adjustment of both my 31 and 77 mm lenses this afternoon. This is a nice little feature. My 31 was WAY off (-6), the 77 was -4. I'll check them both more carefully this weekend to make sure I have them as close as possible. The camera has a lot of trimming adjustments available, which is both nice, and at the same time, a bit of a pain, since the temptation is to go looking for problems that may, or may not, exist. However, I am happier with an adjustment that I can ignore until I need to fix something than not being able to make an adjustment if something goes sideways. Something I noticed today that I hadn't seen on my K10 was my IR trigger makes a tiny little red catchlight in the subject's eyes. I did a couple of dozen portraits of a young lady that I know who happened to be at the coffee place next door to the studio, but foolishly, I forgot to reset the ISO from 800 to 100, so they aren't as nice as I would like them to be. Had I made this mistake with the K10, the images would be next to unusable, but with the K20, they are still OK, but could be better. Be careful when removing the cover for the PC socket (THANK YOU PENTAX!!!!) as it is very small and fiddly. I thought I had lost mine at the camera store, but the sales clerk was able to retrive it from under the counter where it had landed. The DNG files are massive, varying from just under to just over 23mb each, which is 7 mb larger than the K10 DNG files. I have no idea why there is a size variance though my K10 DNG files vary somewhat as well. It seems to me there shouldn't be. It's good to have mysteries in one's life though. My initial impression is that this camera is definitely a worthwhile upgrade to the K10. William Robb -- 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.
