CanonEF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens for SLR Cameras

Perfect landscape lens with outstanding quality in build and performance = 5*

If you already own one of Canon's L series lenses then your expectations for this lens will be high. What you will find is that build quality, focussing and weather sealing are all up to the L standard.However if you compare it with say the excellent 70-200 f4L IS USM lens then you may find this lens a little disappointing when you first use it. What you have to remember though is that producing an ultra wide angle zoom lens is a whole lot different to producing a telephoto zoom. Achieving a balance between resolution, distortion, control of flare and aberrations on an ultra wide angle zoom means that some compromises have to be made along the line.Certainly, the corners of images on a full frame body at full aperture are not going to be as sharp as the centre. There are also going to be some signs of vignetting at the wide angle end of the range and a touch of purple fringing at the edges of the frame. None of these are deal breakers though because you only have to compare it to what else is on offer to realise that Canon did a great job in producing this lens at its price point.There may well be better ultra wide zoom around but they all cost an awful lot more. Just a look at what this lens can do over 95% of a full frame image taken at a sensible aperture of f8 - f11 will tell you this is a lot of lens for the money.UPDATE: After a lot of use, I can tell you that this is a superb lens worhty of its L designation. In fact many reviewers say that is superior to the more expensive 16-35L lens. Having not tried one of those I can't comment on that but I can tell you that this is tack sharp at full aperture almost to the corners of the picture. I can also tell you that it is a versatile lightweight lens that well suits full frame Canon cameras.

This review relates to this lens on an APS-C sensor. Results on full-frame and film cameras may be different.17-40 is a fairly nice range as a standard zoom on APS-C cameras (like the EOS 300D, 350D, 400D, 20D and 30D). It equates to about 27-65mm as 35mm equivalent. The constant max aperture is also a nice feature, as is the robust build quality. Best of all, the 17-40 L delivers lovely contrast and colours and is very very sharp. These are certainly good things in a lens and I really like the way some images taken with this lens seem to have a vibrancy not found in lesser lenses. However, the lens also has its downsides which seems to get ignored by those with an L-lens fixation.For instance:- the lens is heavy, You really know you have it on the camera body. It certainly makes a 400D feel imbalanced. That's not true with a 30D, but it's still heavy.- f4 is not "fast". Neither is it "slow", but it doesn't offer as much creative control as, say a Sigma 18-50 f2.8- the lens is very expensive when compared with other options like the Sigma 18-50 f2.8None of these may bother you as a consumer, but unless you need a wide-angle zoom for a full-frame and standard zoom for APS-C, I would consider other options also. There are faster, lighter and near-equal performing lenses out there for APS-C cameras for considerably less money. The main advantages the L has over the Sigma and Tamron alternatives are: the Canon name which holds its value better if you want to sell it on later and the Canon has the lovely USM mechanism, which means near-silent operation. Thankfully, it's also less conspicuous than other L lenses as it's not grey/white in appearance.I don't know that digital cameras will necessarily revert to full-frame when sensor prices come down. After all, it's possible to get 10MP on an APS-C frame without any detriment to image quality. 10MP really is enough and APS-C means that cameras and accessories can be that much smaller and lighter than full-frame equivalents. There's no real advantage to full-frame unless you are a pro - and just because they used to use medium format cameras a few years ago didn't mean the rest of us did also.It's a very very good lens, but the extra-premium price is tough to justify. I feel this is a great option for those looking for a wide angle zoom on a full frame camera... but as a walkabout zoom on an APS-C camera, I'm not sure this is the best option.

I've had this lens for around four years and it used to get a lot of use on my 10D as a standard walk around. While there may be better alternatives in this role on a crop sensor, I always intended going full frame so the attraction of this lens to me was the fact that it also makes a good wide zoom on this format, thus offering a logical upgrade path. Since getting the 5D it has been replaced as my general lens by the 24-105, but as planned it then stepped into its new role as a wide zoom and boy is it wide on full frame.Tough build, good IQ, lovely ring USM focus, versatility and a reasonable price made this a no brainer for me.

Hi, this lent is coming my favorite of my collection I have, is the 17- 40mm of canon. It’s a fisheye lent so you can make a 180° photos, high quality of colors and good resolution.I wish you my review help you to diced.

Only used briefly but so far works great,.

Ich bin sehr zufrieden

Uso no Full frame, e acho fantástica. Uma lente que captura cores e detalhes, de forma clara e qualidade óptica. Excelente para interiores e paisagens.

Awesome product. A beginner in the L series but serves as a tank for general purpose photography. The lens is particularly sharp above 24 mm at focal ranges of f5.6 or more.

As usual, top quality lens from Canon!!