Can someone please give some advice on these lenses

Hi guys,

Ok I am really getting into photography now and am gonna grab a 40D pretty soon. I was thinking about getting just the body on it's own and picking my own lens. I found this lens:

http://www.warehouseex​press.com …/default.aspx?s​ku=1017291

It has a fixed aperture and a nice minimum focus distance, but I need to know...

1) If it will autofocus and work with the 40D.

2) It doesn't have HSM (sigmas equiv to USM), I was wondering how much slower (if any) this lense would be to autofocus over something with HSM and if it's noticable. Not worried about noise.

3) Is the IS feature on canon's lenses actually useful at this sort of focal length and beneficial enough to go for a canon over the sigma?

4) I also need to know (being fairly new to photography) if the fixed aperture would have big advantages over something like this;

http://www.warehouseex​press.com …/default.aspx?s​ku=1002750

which has IS and USM. Looks very much like the kit lens however I have been told it's not quite the same?

Big props to you guys for giving out so much helpful info for free

Both work on the 40D. The Sigma lens biggest attraction isn't just that the max. aperture is constant through the zoom range, but that it is a fast f/2.8 (fast for a zoom that is) vs the much slower f/4-5.6 of the Canon. The Canon is thus one stop (f/4) slower at the wide end and two stops slower (f/5.6) at the long end.

The IS on the Canon is nice, and can overcome some of the limitation of having such a slow lens. If you tend to shoot still subjects or landscapes, the IS might be better than the faster aperture. The lens is also a lot longer (85mm vs. 50mm) on the long end.


If you tend to shoot mostly portraits, events, kids playing or action then you generally want faster lenses more than you want IS, at least in the <100mm range.

Over 100mm you want both fast apertures and IS, which generally means piles of money.

There are four other lenses in this range you should consider:
Tamron 17-50 f/2.8
Sigma 17-70 f/2.8-4.5
Canon 17-55 f/2.8 IS USM (Pricey, but includes f/2.8, IS and USM in one lens)
Canon 18-55 f/3.5-5.6 IS

The EF-S 17-85 USM IS is a good compromise... it has better IQ than the 18-55 IS, but not as nice as the 17-55 f/2.8 IS, but at half the price, and you get more range.