Its advantages include its utility as an all-purpose wide angle lens (capture range from slightly wide to ultrawide) and its relatively low price for a complicated semi-specialty lens

That's a great range for taking pictures in the forest preserve for example

This especially true on a 1.6 FOVCF body (20D, 30D, 350D, 400D, etc), where the range is more like that of a normal zoom, at the cost of the super-wide advantage

The best aperture range was between f/8 and f/11.

The extra range on the short end of this lens becomes really important when shooting group pictures, landscapes, or your shooting space is really tight.

This is a very good lens offering a useful range of focal lengths

As there is quite a bit of difference in build quality as well as price range, that should come as no surprise

The range is incredibly useful, whether as a 17-40 on a full-frame, 22-52 on a 1.3x, or 27-64 on a 1.6x crop camera like the Digital Rebel or 20D.

The range with a full-size sensor is perfect for landscapes and interiors.

Yes, it won't be an ultra wide angle lens, the way it would be on a full frame camera, but the range is so useful that I find it very hard to take it off my camera and replace it with any other lens I have.

17-40 excellent range and size and all my 77mm filters fit, perfectly satisfied with this lens.

Almost all the third party options (sigma, tamron, tokina, etc) covering this range are as sharp, if not sharper

The 1.6X multiplier of my Rebel XT takes away the extreme wide angle capability of this lens, but nevertheless the range is impressive at an effective 27 to 64mm

On the whole, this is a fantastic lens, with a great range

I like landscape and interior photography and this is definitely my favorite lens of those I own; with the 10D's 1.6 crop factor this lens has a nice equivalent range of 27.2mm - 64mm

This is a very usable range and being an L series

Wow, a fantastic lens that gives the L series a run for their money in terms of great images - with IS to boot and a REALLY handy telephoto range for both indoor and outdoor!

This it an awesome lens, it has great clarity and with the 17-40mm capability a great range of uses

This it an awesome lens, it has great clarity and with the 17-40mm capability a great range of uses

Some Photoshop - Shadows and Highlights - is all that is needed to bring it all into the dynamic range of the photographic papers we use

Some of the main competitions (sorted by price):- Sigma AF 17-70mm f/2.8-4.5 DC macro: Good zoom range with macro, and generally solid performance if you can get a good sample

(especially between f/5.6 and f/11 at night!)- lightweight for L glass- non-extended zoom- good zoom range...makes it a versatile walk-around lens during the day- excellent performer on a 1.6x FOVCF body (I used it on the XTi, 10D, 30D, and 40D).

The 17-40 focal range is excellent for a walkaround

Rapid focusing (with sufficient light)L-quality buildReasonable weight and size (solid but not unwieldy)Sharp!Tight focal range - can get within 6-9" of a subject with the right light

17-40mm is a good range to get

Extremely sharp and a great range of

In summary, if the focal length range of the 17-40 doesn't overlap too much over your current lens kit and you favor high-quality wide over good quality ultra-wide, then this lens is right for you.*NOTE: If the 17-40's inclusion of a lens hood is influencing your decision in anyway over the 10-22, don't let it be.

17-40 excellent range and size and all my 77mm filters fit, perfectly satisfied with this lens.

Yes, the long end doesn't go very long, but in my opinion the range you gain at the wide end is more valuable

This lens has excellent qualities, pictures are sharp perfect and the zoom range is ideal especially for interior shoots as always the L type lens delivered.

Great lens for the beginner as well as for the seasoned pro

While it is reasonably sharp at f4 across the focal range, it is not as sharp as when stopped down to f5.6.

It's as sharp as or slightly sharper than the 24-105 f4

This lens is nowhere near as sharp as the Canon 50

Not sure if this is normal on an APS-C camera or not, but I'm a little mystified as to how this is happening!

It's just does not have the 'hoopla' of lenses like the 70-200mm, but as good as that is for telephoto, this is superb for wide angle

But sharpens up a lot in the corners by going to F/4.5 and is as sharp as it's going to get by around F/8 where it seems about as sharp as any zoom I have and is approaching the sharpness of a prime lens at 17mm

The pictures were nowhere near as sharp as I had hoped for (Although I had no illusions that every picture would be tack sharp just because I got a new fancy lens.

Nowhere near as sharp as you'd expect from an L lens

I'm still reviewing, but my initial thoughts are the focus isn't quite as sharp as it could be?

I use it to shoot from an elevated angle as well as for interior photos.

(670g) ($575) (slow, not a walkaround)Tokina 17-35/4 (600g) ($400