Sigma 24 - 70 2.8

[nipplebass]

I'm buying a second hand sigma 24-70 and I'm really pleased with it. I noticed when shooting at 70mm 2.8 on auto focus the picture was pretty soft. thought this was just because it's a cheap lens and know not alot of "budget" lenses are pin sharp wide open at the longest focal legnth.

I tried manually focusing using live view and zooming right in and noticed a huge difference in sharpness.

Any ideas how to correct the autofocus? would I need to send the lens/camera away to be calibrated?

Shooting on a canon 7d btw

 

[Nod]

If your camera has a micro adjust facility, it'll be explained in the manual - a very handy reference book!

Be aware that some Sigma lenses have QC issues and it's possible that the copy you're looking at is one of the problem ones. If it's within warranty (some Sigmas have 3 years of manufacturer's warranty IIRC) and a genuine UK import rather than a gray, Sigma should sort it for you. Not sure if their warranty is transferable - if not, get the seller to sort the issue before purchase.

 

[neil_g]

thought this was just because it's a cheap lens and know not alot of "budget" lenses are pin sharp wide open at the longest focal legnth.

thats a very sweeping statement, there are plenty of budget lenses that are sharp all the way through.

which version of the 24-70 do you have? the earlier non-hsm one was known for being a bit rubbish.

my hsm version was certainly sharp wide open at the long end.