Last week Canon announced two new magnificent looking tilt and shift lenses. The the TS-E 24mm f/3.5L II and the TS-E 17mm f/4L. Nikon calls these kind of lenses "perspective correction" lenses. What ever you call them, these lenses are designed for architectural photography because they do two things that architectural photographers want to do:
There's a article over at the-digital-picture.com that gives more in-depth description of tilt-shift-rotate lens features and use, along with a gallery of photos shot with the older version of the Canon TS-E 24mm f/3.5L.
For those of you that are not PFRE flickr group regulars there are several interesting discussion threads relating to tilt-shift and perspective control lenses in the PFRE flickr discussion group. One particular link that David Palermo suggests is a good article on tilt-shift lenses.
For some, I'm sure the question that will come to mind is, " why pay $2200 USD for a lens when I can create the same effects in Photoshop?". This is a valid question. You can do very respectable interior and architectural photography without a tilt-shift lens. However, the ease with which you can straighten verticals and create selective focus effects in the camera is significant. It depends on your shooting philosophy and style. Some photographers would pose the question in reverse, "why spend time in post processing when I can create the image in the camera?" There's no right way, just different approaches to creating images.
It's important to understand that a lens like the Canon TS-E 24mm f/3.5L II is a close to the perfect lens for interior and architectural photography even if it didn't have the tilt-shift features. The "L" in a Canon lens description means a lens is the highest possible build and optical quality. Most Canon L lenses are over $2000 USD. Also, to me, 24mm (on a full frame sensor camera) is the perfect interior focal length. I worked for many years with a 24mm lens on my film camera and was pleased with the results.