THIS IS ONE GREAT LENS ,VERY SHARP WITH GOOD CONTRAST ,FUN TO USE AND GREAT

Amazing color, contrast, and sharp

Contrast is very good

Contrast and color with this lens is excellent.

But for the price it has excellent IQ and color contrast.

Pro: excellent picture quality, great picture contrast, smooth focusing motors, excellent glass quality

Pros:- Among the very best build quality.- Excellent, buttery smooth, super fast front-focus system.- Top notch color and contrast

which this lens delivers- contrast is great, color is

I continue to be impressed with the sharp high contrast photos and the super fast auto focus

I have the 5Dm2 and this is my first L-series lens (I couldn't afford the 24-105 when I bought the body), and boy is it great!I love the realistic skin tones, high contrast, and amazing color

the contrast and sharpness are great, it is relatively fast and extremely reliable, the success rate with this lens is excellent

As one would expect from L-series glass, clear with good contrast and color

Contrast was very good and I couldn't tell any difference between the two lenses

Those other lenses are pretty good, but just can't quite match the wonderful color, contrast and sharpness of the 17-40 across its range.

The contrast and colors are vibrant and it's sharp from edge to edge wide open

This lens does a fine job, but I did notice that when I took picures of builings with words or other features that had good straight-lined contrast, the sharpness was exceptional

Colours are rich and vibrant, and the contrast is great

Also between 35-40mm, the lens' transmitted contrast degrades very fast (look at the MTF charts on canon's website)

The great contrast this lens produces (blacker blacks, richer colors), and the especially flat field of view are the frosting on the cake to make this a great option for landscape shooters demanding a great lens.4 stars for the crummy performance at f/4 and at 17mm.

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.