auto focus sigma/canon issues

[jann1033]

ok , i got my sigma lens rechipped to go with my rebel xt and when i first got it it seemed to be working fine but now i am having major problems with it locking into focus. it just keeps goiing in an out and never focuses..tried it with a number of settings, macro, normal, a couple auto modes and the set your own modes, it happens in all of them I tired....i can put it in manual and focus it alright so i am guessing it is the auto focus mechanism...this is what it did with my old camera and i assumed someone had messed it up when my daughter took it to Hawaii a couple yrs back. i 'd still think that was the case if it had not worked fine rather than like this the first few weeks i got it back from rechipping. so is this the focus problems i've heard about with sigma/ canon and if so is there anything i can do about it ( other than /until i / buy another lens i mean)

 

[ndelaware]

Jann, not that this is the case but the darker it is the harder it is for a lens to autofocus. If it won't autofocus outside on a bright day it is a problem with the lens.

 

[Kelly Grannell]

how dark is the environment?

 

[WillCAD]

That sounds similar to a problem I had a while back with my old Sigma 28-200. It turned out to be a stripped gear, and Sigma fixed it for $60. Works like new now - and is packed in a box because I don't use it with my Digital Rebel...

 

[0bli0]

assuming it's bright - how far are you from the subject? does it change depending on the distance you are from the subject? does it change depending on how far you're zoomed?

 

[jann1033]

with my old film rebel it always did it if it was indoors and low contrast situation...then it started doing it outdoors, indoors any place any time . they are supposed to check the lens when they rechip it but it didn't do it at first when i got it back...now it's back to any time any place ....at this stage i'm just forgetting this lens due to my total frustration and getting something else

 

[ndelaware]

I think that is your best bet jann.