Good info. Thank you Bulent! On Tue, Feb 10, 2015 at 9:01 AM, Bulent Celasun <[email protected]> wrote: > Darren, > > You might want to visit the PDML archives as I remember this issue was > discussed a bit, earlier. > > Relatively modern Pentax lenses "inform" the body about their > identity. Bojidar Dimitrov's site can be of help for this, I think. > The camera firmware includes a database of all those lenses. > The adjustment will be saved for that particular lens (if you select > that option). > Since Pentax does not openly support other K-mount lens makers, their > lenses are not in the database. > Still, they usually (most of the time) find ways to declare an (albeit > false) identity to the body. > There is nothing you can do about these. > > There is no consensus on the optimal adjustment for zooms. > One view (which I share) is to select a mid-range focal length for adjustment. > The other view is to select the focal length you would be using most. > I am sure there are others who may select to optimize the focussing > for one of the extremes (probably the tele end). > > My K10D needed extreme values to work with some Pentax lenses. > Now I understand that the body needed calibration. > My later bodies were much better. Small adjustments were enough for > K20D and even smaller for K5. > > I believe if you consistently need to add the same value for most or > all of your lenses, you may as well consider servicing the body. > > Bulent > > > > > > > --------------------------------------------------------------------- > http://patoloji.gen.tr > http://celasun.wordpress.com/ > http://www.flickr.com/photos/bc_the_path/ > http://photo.net/photodb/user?user_id=2226822 > http://www.pentaxphotogallery.com/artists/bulentcelasun > > > 2015-02-10 15:42 GMT+02:00 Darren Addy <[email protected]>: >> So I've yet to perform any sort of AF adjustment on any of my cameras, >> but I'm curious to see how my various AF lenses perform in this >> regard. If you are in the same boat, here are a couple of links - the >> first showing/explaining the concept: >> http://vimeo.com/lensalign >> And the 2nd showing you how to make a LensAlign tool for around $10. >> http://www.ahfairley.com/Tutorials/LensAlign/FocusTool.htm >> >> I'm more than a little fuzzy about how the camera knows/remembers what >> lens is on the camera. I'm guessing that it somehow records some sort >> of I.D. from the lens when you perform the AF adjustment setting, but >> I seem to recall reading that some lenses "report" (or are read by the >> camera) as a different lens. Can anybody explain how that works or >> point me to a page that explains it? Also, I'm assuming that this >> works with third party AF lenses like my Sigma EXs? I think the most >> critical lens to do this with is my Bigma. >> >> Also, on a zoom with a big range, like the 50-500mm, do you recommend >> doing the align at the longest end or somewhere nearer the middle of >> the range? Or does it make a difference. (I don't think it SHOULD, if >> the lens is put together correctly, but...) >> >> Thanks in advance for any guidance or explanation. >> >> -- >> Life is too short to put up with bad bokeh. >> >> -- >> 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. > > -- > 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.
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