the cheaper (not lesser) canon wide angle zoom

Anyone looking for a wide angle zoom for their Canon body only has a few choices available to them. There is the cheap (EF 20-35mm f/3.5-4.5 for ~$350), the not so cheap (EF 17-40mm f/4L for ~$700) and the uber expensive (EF 16-35mm f/2.8 for ~$1400). Oddly enough, each step is roughly twice the cost of the former.

Most people considering the EF 17-40mm f/4L are basically choosing between the 17-40 and the 16-35, so it's important to note the differences between the two lenses. The first most obvious difference between the two lenses is that the 17-40 is 1mm less wide, but 5mm more long. The wideness you don't really notice too much, but the length you just might. Is it a compelling reason to get the 17-40 over the 16-35 because of the extra length? Certainly not.

An equally obvious difference between the two lenses is the difference in the maximum aperture. The 16-35 is a full stop faster than the 17-40. For most, this is the most compelling reason to get the 16-35 over the 17-40. Aside from being a full stop faster, the 16-35 does also exhibit a fuller bokeh than compared to that of the 17-40, but the bokeh on the 17-40 is still quite good.

Optically, these lenses are pretty much identical. They both produce sharp images with good contrast. They are about the same size and about the same weight. Both come with the same lens hood that should be used whenever shooting in conditions where you might get flare. Because of the nature of the lens, I do find that both of the lenses have a tendency to flare whenever facing the sun, however it has been my experience that the 17-40 exhibits fewer artifacts as a result of lens flare.

The 17-40mm f/4L is an excellent lens and if you don't mind the trade off in the extra stop in speed, it's a great value. If you find yourself shooting in low light conditions all the time, this lens will not give you the speed that you want. If you find that you need exceptionally shallow depth of field, this lens will not give you what you want.

If you want an optically excellent reasonably priced wide angle zoom, this lens is perfect for you. I shoot with the Canon 10D and the 1.6x focal length multiplier makes this lens into a very usable range. Ever since I got the lens it has become my walkaround lens. I have never regretted the purchase and I highly recommend it to those who are on a budget but need the wide angle zoom.