I have Sigma fisheye 2,8/10, which is a very nice lens for its purpose. However, K-5 does not recognise it correctly. It registers the lens in the EXIF data as Sigma 70-200 mm (!) and the shake reduction SR acts horribly wrong. Without SR the lens is operable, but the EXIF data still wrong.
Even worse with K-1: the camera locks up (freezes) when I try to switch it on with this Sigma 2,8/10. No matter if the body is set to FF or crop mode.
Is there an obvious reason for this? Maybe in case of K-5, that the camera firmware is too old to recognise the lens - or that the lens firmware is buggy. For K-1 - I've no idea.
---------- Post added 04-20-21 at 09:28 PM ----------
Originally posted by c.a.m The only time I experienced a mismatch was with my DA* 50-135 and K-5 (or K-5 II, don't recall exactly). The lens would not autofocus reliably at the longer focal lengths from about 120 to 135mm. I suspect the issue might have been caused by the lens's failing focus motor (i.e., SDM). It worked properly after the lens was repaired, and when subsequently converted to screwdrive.
Could the problem be caused by a serious front- or back-focus issue? Have you calibrated the lens via the AF Fine Adjustment setting?
- Craig
I have needed to fine tune the AF via camera menu a couple of times. E.g. SMC-F 2,8/135 when used with K-3 - a clear case of front focusing, and I missed a few otherwise very nice shots because of that, before I learned to fix it. But as long as it's fixable, I wouldn't say it won't work.
In addition, I used to have occasional focusing problems with DA 17-70 and K-5, but it must have been the SDM defect with the lens irrelevant to the body.