REAL WORLD Lens Test
EF 17-40L f/4 USM
These lens tests are designed to show you what a rank amateur can do with these lenses.
Very little adjustment has been done to these images and, where indicated, actual straight-from-the-camera images are provided.
In other words, if "I" can get these results, you should be able to, as well.
When I bought my first DSLR, the Canon Rebel XT, it came with a "kit lens" of 18-55mm range. One of the major selling points of a DSLR is the availability of a wide assortment of lenses, so while you may first want more of a zoom lens or a macro/portrait lens, sooner or later you'll want to upgrade your wide angle zoom.
One option is the 17-40mm f/4L USM (retail US$799.99), which comes highly recommended, almost universally so, among reviews. True enough, the build is solid, the focus VERY fast, the images clean and clear. The 17-40mm is a wonderful step up and attractively priced for L glass.
The very first impression was, “Gee, this thing is heavy.” Not overly so, but heavy in the sense that it is a solidly put together lens, much heavier than the kit lens it replaces. Compared to that kit lens, the clarity is also impressive. Here's how the 17-40 stacks up physically with my other lenses, from left to right:
background: 50 / 100 / 70-300L / 70-300
Standing next to the kit lens, the difference is obvious. But where the kit lens protrudes as it zooms, the 17-40 does not. And the kit lens takes a 58mm lens cap, the 17-40 takes a whopping 77mm. With glass that large, I had to put at least a UV filter on it, and normally a circular polarizer, if only for protection and peace of mind.
The 17-40 also takes a funky lens hood, which draws comments from the uninitiated, who must think that piece of plastic somehow makes the whole camera look special. Once I got used to it, myself, I thought it looked pretty cool, too. How it functions remains to be seen.
The lens has the requisite gauges for focal length and subject distance, along with one switch (auto or manual focus).
So, let's get to shootin'.