[David Smith]

Originally Posted by derekbez

You've obviously looked at this one:
http://www.sigma-imaging-uk.com/lens...4-70mm_hsm.htm
(Sigma 24-70 2.8 HSM)

Yes-I have 'googled' comparrisons between that & Canon----also between Canon 24-70mm & 24-105mm. You could go crazy with all the different opinions.
Some have said the Sigma is virtually useless at the 24mm/wide open while others have said the Canon 105 vignettes a lot.
I can't think of too many occassions when I would shoot at 24mm wide open but it's a shame to pay for that option and not be able to use it.
I have got used to having IS on my 17-85mm but is that important on 'comparitively' short lenses ?
Has anyone got all 3 lenses they could lend me for just 6 months?