Originally posted by AdrianM I have the Sigma 500/4.5 APO DG EX, the Sigma 100-300/4 APO DG EX and the Sigma 70-200/2.8 II. I have no difficulty recording individual focus corrections for each of these lenses on my K5 or K20D, although I note as you have done that the 500 does not identify correctly. My firmware is 1.13. For reference, the focus correction on the three lenses respectively is +5, 0, and -7. My focus test for the 500 is shooting at soft drink cans at about 20 metres. Once adjusted at +5, I would describe the 500 as 'dead sharp' and I usually use it at f5.6 to get enough depth of field to shoot birds. Not sure if this will help the lens confusion, but I hope it helps with the focus adjustment.
In PhotoME exif data:
- the lens ID for the 500 is 3 +0 +0 +0 and comes as a "Sigma (Model Unknown)"
- The 100-300 records as 3 +46 +0 +0 and identifies as either a 100-300 f4 or a 70-200.2.8
- The 70-200 2.8 identifies as 8 +255 +0 +0 and records as a 70-200 2.8 or 150-500 f5-6.3
You might care to check the data for your 180/3.5 and see if it is the same as the 500/4.5
Thank you for the reply. Have you tried to check what focus correction value is used when different lenses are attached? Let's say I set +10 for 500/4.5 and +4 for 180/3.5. If I used the 500/4.5 before my K-5 keeps +10. When I attach the 180/3.5 and check for the correction value my camera still shows +10 instead of +4 that I previously saved for this lens. And vice versa. For example when my FA*300/4.5 is attached instead of 180/3.5 the camera shows proper +3 which is set and saved for this lens.
My firmware version is still 1.03. However, I have reasonable doubts that these updates fix the Sigma lenses AF correction and recognition issue. All newer updates were about GPS, Astrotracer, and SDXC cards functionalities, and I did not downloaded them.
Unfortunately I have no access to PhotoME now, because I'm on two iMacs and do not use virtual Windows. However, you may be right about same identification of 500/4.5 and 180/3.5. I just checked my Sigma 8-16. K-5 does save it correction. And neither 180mm or 500mm picks up the value of 8-16. So, the issue may be very local, affecting only two my lenses. It's still inconvenient a bit, though.
Thank you very much for your help and the tip. I may ask somebody tomorrow to check my both jpeg files to confirm it.
My regards,
SG