If it's on a crop sensor, then definately the 24-70.
Out of the Sigma 24-60, the 24-70 and the 28-70 in order of goodness you're looking at:
1) Sigma 24-60
2) Sigma 24-70
3) Sigma 28-70
The Sigma 28-70 is only 3rd because there is nothing worse above it
Its really the runt of the litter, unless they have MASSIVELY improved it with a DG re-spin.
The new HSM version coming soon is going to be around £650, so double the price of the current one.
The new HSM version coming soon is going to be around £650, so double the price of the current one.

That would make me strongly consider purchasing one right now without HSM - I never use autofocus, so now would appear to be the time to buy!
Cheers,
James
Where did you get that price from?.
I asked 'em
Sigma are VERY confident in this lens and its optics. It could be worth it.
You might get 110% of the performance for 90% of the price![]()
Yea, it'll be a bargain if it's true!
Personally I'd chuck the 17-70 into that mix too - every bit as sharp as the lenses mentioned, cheaper and more versatile. The only issue will be f4 at the long end, but it's only an extra stop and might be able to be compensated for in other ways?
The 24-70 is a beaut of a lens though, but I haven't had good experiences with the 28-70 - both of the ones I had (on approval) were soft as custard.
Cheers,
James
Oh, translated version of the Sigma Japan page on the new HSM:
http://translate.google.com/transla...refox-a&rls=org.mozilla:en-US:official&hs=Z8d
Note the MRRP price: 123,800 yen which is about £930. Makes me think Puddleduck is about right price wise hence I went for the none HSM for now.
Reading that is making me hungry... Food can also be mounted on the headliner effective shade.
Thats good to know.
At what focal length does it start to go above 2.8 please?
The new HSM version coming soon is going to be around £650, so double the price of the current one.
At that price I'd spend another £150 or so on the Canon....
Steve
Even if the Sigma is better optically?
Just got my 24-70mm f/2.8 this morning. Superb lens for the money. The build quality is definitely nowhere near that of the Nikon 24-70mm I have had a go with, but for £216 I wasnt expecting it! I seem to have gotten a nice sharp version so am over the moon!!
(canon version) .I recently got the 24-70mm and I have to say that it is very heavy and I think its a bit soft wide open at 70mm but perhaps thats just the AF being a bit off.
Its not perfect but not bad for the price.
sid
Even if the Sigma is better optically?