Excellent specialty lens - Canon TS-E 17mm f/4L Tilt-Shift Lens 3553B002

This is Canon's widest tilt-shift lens, and therefore a great choice for architectural photography. You can use it to keep parallel lines parallel. You can also do the opposite: exaggerate the apparent convergence, to emphasize the height of a tall building, say.

Other effects you can achieve with a tilt-shift lens are making scenes look like they're miniature, and putting select parts of the image in focus.

I would not recommend this as a first lens. It does take some getting used to. You can shoot hand-held, but it's best used on a tripod. There's no zoom, and no autofocus. You must "zoom with your feet," and focus it manually. But if you already have a good selection of zoom and prime lenses, and want to try something different, this lens will give you a different view of the world.

Pros: does things ordinary lenses can't
Cons: not for beginners

This review was written in the old system and had content requirements that are different than reviews written today.