Some impressions about new Canon 17-55 2.8 IS and some links to samples for illustration.
(All pictures are at original size, be careful to choose « original » option under the picture, the oher sizes are downsampled by Pbase - shoot hand-holded, IS, body settings neutral, no post-processing)

I don’t agree with comments that give a 10, for a perfect lens. A 9 seems to be maximum for it. Perhaps better, but only after post-processing by a good software.

Two little problems in my opinion, the vignetting, very present wide open, disappear at 4 or 5.6, but…
The lens seems very sharp at 4 and up, but for sure a little softer at 2.8.

About the vignetting, I have made some test shots at different apertures, and ther compared with Canon 10-22 and Canon 50 1.4.
It is better on this point than the 10-22 (hard vignetting wide open…) but the not APS-C 50 1.4 is clearly better than the 17-55, for a use at 50mm at 2.8.
Tests visible here :
http://www.pbase.com/isogood/image/63255188


Some sharpness test pictures here, you may see the difference between 2.8 and other apertures stopping down.
EXIF are under the pictures.
http://www.pbase.com/isogood/canon_17_55


This said, sharpness is one of the qualities of this zoom, well sustained by the IS, imperative for me, who shoot often in low light, where no flash or monopod allowed (museums…)
You gan get sharp shots at 1/8 sec, if you don’t drink too much beer before…

Other quality of this zoom is the color rendering, well in Canon tradition, quite perfect in terms of natural, neutral, or saturation, clearly better (I mean different…) of Tamron or Sigma on this crucial point.
On my EIZO screen, it is quite impossible to see a difference between the model and the picture on the screen, not reach the prime L lenses, but not so far.
Perhaps the 24-70L give better saturation and contrast, but not sure…

We reach the perfection with the AF – USM focusing system, superb of precision, fast and silencious. Works perfectly.
The zoom ring is very sweet to move, confortable. Here again, Canon is the best.

I have read some complaints about flare, so I tested it in the worse possible conditions, ok, if we want to make flare, we make flare…. But nothing terrible at all…
Chromatic Aberrations are very well controlled, only in extreme edges, as you may see it (with the flare) on some shots of Effeil tower in back-light :
http://www.pbase.com/isogood/image/63255874/original

You may see also similar shots to compare taked with Canon 10-22 and Canon 50 1.4 on these galleries :
http://www.pbase.com/isogood/canon_10_22
http://www.pbase.com/isogood/canon_50mm_14


I could say about this comparaison that at 50mm I have a little preference for the 50 1.4 against the 17-55 but only in high lights, cause in low light, the IS is an enormous advantage.
At 17mm and at 22mm the 17-55 is noticeably better than the 10-22, less vignetting, better sharpness, no contestation.
So my 10-22 became only a 10-16… Thats clear…

I have no Tamron or Sigma at this time (all resell or returned) so I can’t compare same shots, in this range, but it would be interesting to do that.

Canon is really ridiculous in persisting not give the hood with a lens at this price, and this hood is impossible to buy at this moment in europe. No stocks at Canon.
This hood is essential for the quality of the pictures but also to protect the front lens, very exposed.
I use the EW-83E from my 10-22, not sure is the best way, but better than nothing…

Price is high, sure, 1200 USD for me, but there is no real competitors with this quality and features, so no real choice possible.

I think the lens worth 600 USD and we have to pay again 600 USD for the IS.
If Sigma and Tamron same range for APS-C would have IS, for sure their prices would not be so far from Canon (see Sigma 80-400 OS…)

So much more qualities than defects, and for sure a good buy if you need all the features.
Now we have to see with use if pictures produced worth the price, and if the build quality is solid…
So come again for a completed review in some months.

Some recent samples, interiors and exteriors, here, August 2006.

http://www.pbase.com/isogood/venice