From: J. Clarke on 6 Jun 2010 09:45 On 6/6/2010 8:47 AM, Pete wrote: > On 2010-06-06 12:53:00 +0100, J. Clarke said: > >> On 6/5/2010 9:28 PM, Pete wrote: >>> <> >>> Sorry, I forgot to include the vignetting problem in my list. I also >>> forgot to include that some third party lenses and tele-converters are >>> unable to communicate their defects to the camera so that it and the >>> editing software can automatically correct for them. >> >> Lenses do not "communicate their defects", they communicate the lens >> type. The defect correction is based on a lookup table built into the >> camera. No camera manufacturer of which I am aware includes correction >> tables for third-party lenses. > > I haven't seen camera firmware or Capture NX2 updates when new lenses > become available so I don't know how it works. I find auto correction of > CA and pincushion/barrel distortion very useful. > > AFAIK third party tele-converters do not communicate the correct data to > the camera. Do Nikon cameras contain correction tables for teleconverters? You're really asking a bit much there. >
From: Robert Coe on 6 Jun 2010 17:03 On Sun, 06 Jun 2010 07:53:00 -0400, "J. Clarke" <jclarke.usenet(a)cox.net> wrote: : Lenses do not "communicate their defects", they communicate the lens : type. The defect correction is based on a lookup table built into the : camera. No camera manufacturer of which I am aware includes correction : tables for third-party lenses. IIRC, some high-end Canons let you input your own correction tables. Bob
From: Robert Coe on 6 Jun 2010 17:13 On Sun, 6 Jun 2010 07:11:34 -0700, Savageduck <savageduck1@{REMOVESPAM}me.com> wrote: : On 2010-06-06 04:50:36 -0700, "J. Clarke" <jclarke.usenet(a)cox.net> said: : > Uh, how does keying the _rear_ lens cap, which is _removed_ before the : > lens is mounted on the camera, make "Sigma" appear "written the right : > way up"? : : It doesn't. : "Sigma" isn't written on the rear lens cap of the Sigma lens I own. It : might appear on others, but I doubt it. What is there is, in lower : case, "for nikon". : Replacing the cap by feel when changing lenses makes it so much of a : PITA, I have replaced the offending cap with a Nikon product. You could always switch to Canon. The Canon cap and the Sigma cap for Canon are keyed identically and will fit in any of three positions, 120 degrees apart. :^) Bob
From: Robert Coe on 6 Jun 2010 17:32 On Sat, 05 Jun 2010 20:39:57 -0500, Doug McDonald <mcdonald(a)scs.illinois.edu> wrote: : : > : : > : old sigma lenses were held together with cellophane tape. seriously. : > : > an urban legend. obviously. : > : : I just remembered: just as an old minolta lens was, so is : (I still have it) and old Sigma 500mm mirror lens! REALLY! : The tape was used to prevent the internal "infinity" setting, which was : a rotary screw motion, from changing. I guess I stand corrected. Although if I understand you right, the tape isn't holding the lens together; it's there to maintain a calibration setting. But either way, it seems horseshit. Is it possible that the tape was there to keep the screw from being turned while it was exposed and the doofus who did the final assembly didn't have sense enough to remove it? Bob
From: Peter on 6 Jun 2010 18:12
"J. Clarke" <jclarke.usenet(a)cox.net> wrote in message news:hug9k201dqc(a)news7.newsguy.com... > On 6/6/2010 8:47 AM, Pete wrote: >> On 2010-06-06 12:53:00 +0100, J. Clarke said: >> >>> On 6/5/2010 9:28 PM, Pete wrote: >>>> <> >>>> Sorry, I forgot to include the vignetting problem in my list. I also >>>> forgot to include that some third party lenses and tele-converters are >>>> unable to communicate their defects to the camera so that it and the >>>> editing software can automatically correct for them. >>> >>> Lenses do not "communicate their defects", they communicate the lens >>> type. The defect correction is based on a lookup table built into the >>> camera. No camera manufacturer of which I am aware includes correction >>> tables for third-party lenses. >> >> I haven't seen camera firmware or Capture NX2 updates when new lenses >> become available so I don't know how it works. I find auto correction of >> CA and pincushion/barrel distortion very useful. >> >> AFAIK third party tele-converters do not communicate the correct data to >> the camera. > > Do Nikon cameras contain correction tables for teleconverters? You're > really asking a bit much there. Yes, at least for the 1.7 on my 70-200. The focal length and aperture with the teleconverter appears in the EXIF file. -- Peter |