Sohail1966 said:
Hi Derrel. Your hypothesis regarding the new code for 7dm2 is negated by the fact that if it was true then Canon should have given out upgrade software for all of its pre-7dm2 lenses, while we know this is not true.
The simple facts are as follows: Both Canon, and Nikon keep and maintain proprietary knowledge of their companies' ultrasonic lens focusing protocols and routines, and have in the past, made subtle changes that caused third-party lenses to malfunction, at times on a widespread scale. And yet, those new protocols/changes required no retroactive updates to camera-maker cameras.
I see you just joined here today to reply to my comment about a type of Sigma focusing problem that has affected millions of users before...and the fact that you do not reference actual prior instances of Sigma being "effed over" by the camera companies means you really are just performing some type of knee-jerk reaction in defense of Sigma. Your first two posts are right here, in THIS very thread...posts #18 and #19...huh.
You are assuming that changes Canon made would have to be corrected by updates Canon supplied for its own lenses...sorry, but the historical facts and the massive, wide-scale Sigma-ONLY re-chipping programs of the past prove that you are wrong...the camera makers have proprietary knowledge of every single protocol they create, but the third-party lens makers must reverse-engineer their lenses. This is, sadly, the reason so,so many Sigma lenses suffer from focus malfunctions on Canon and Nikon cameras. As newer cameras are created, even the SLIGHTEST code manipulations or variants that the camera makers implement can render a third-party lens at a severe handicap.
I happen to own two older Sigma EX series lenses, the 180/3.5 EX APO Macro and the 100-300 f/4 EX HSM zoom; both focus like CRAP on Nikons newer than 2005...which is a shame, because these were like $1000-class lenses...that was when Nikon added the AF-ON feature to the D200 series cameras. My "OLD" 1999 80-200/2.8 AF-S still focuses perfectly on even the newest Nikons...
Sorry, but the Sigma 17-50 on the Canon 7D Mark II seems to have focusing issues....please do a bit of searching... this leads directly to 17-50 problems on the 7D-II but good function on the older 7D...on the part of three different owners of the 7D and 7D-II and the Sigma 17-50/2.8 lens...and yet, Canon has not done massive system-wide firmware updates to their millions of cameras in the field...
like here:
7D Mark II Sigma 17-50 f 2.8 EX DC OS -- Canon EOS Digital Cameras in photography-on-the.net forums
CANON has changed something OR Sigma's reverse engineering is not up to snuff. Which do you want to blame? Search Sigma Lens re-chipping,and you will uncover a problem that goes back over a full decade.:
Sigma lens re-chipping - Google Search