Recently, I rented a tilt/shift lens from BorrowLenses.com.
Firstly, yes — you can rent lenses! There are a couple of sites I trust, one of them I already stated, but LensRentals.com also is fantastic. You go online, find a lens/camera body/flash/whatever you want (for any make and model of camera) and they'll ship it out to you with a prepackaged box that's easy to ship back when your rental period is over. It's an awesome service for people who can't afford to purchase some of the more expensive lenses (like myself).
OK, circling back to the point of this post.
If you've never heard of a tilt/shift lens, that's OK. As you can imagine, it tilts and it shifts. But, wait — how?
The lens physically can be tilted back and forth and be shifted left and right after being mounted to a Digital Single Lens Reflex (DSLR) camera. Doing so can create a number of opportunities for your photography.
What are those opportunities? Well, it depends on what you want to do.
Tilt/shift lenses are great for architecture photography because you can adjust the image to prevent distortion in the photo before going into Adobe Photoshop.
However, the neat trick I want to talk about specifically in this post is the miniaturization effect that tilt/shift lenses can have on a scene. The lens that I rented is a 24mm lens, so that's a fairly wide focal length — you can get a lot of the scene into the photo at this focal length, which is good because it's great for landscapes.
The way to make scenes in front of you look miniature is to leave the shift function of the lens alone, and just apply tilt to the photo. To do so, simply unscrew the "lock" knob on the lens so the lens can be moved and then, either by moving it with your hands or using the dial to adjust the motion, tilt the lens up or down (both work similarly).
Doing so causes a blur effect on the top and bottom of the image (or the sides if you chose to rotate the lens, that's possible too) that resembles the same kind of background blur you see in photos when you take a photo of something small. So, taking a photo of a city from on top of a building (a high vantage point to shoot these kinds of images is recommended) will make the buildings and cars look like you could pick them up with your bare hands, much like a to-scale miniature model.
This lens is brilliant, but it takes some playing around with it to make it work.
For instance, whenever you tilt or shift the lens back and forth, there's a little bit of light that is lost and unfortunately your camera won't be able to read that loss of light if you're shooting in any mode but manual. I tried AV mode as I shifted the lens up a little and the camera tended to overexpose the image.
So, naturally, the way to correct this is to shoot in manual mode and just take a few test shots to get the exposure right.
Another drawback to this lens is that it is manual focus only. Well, that's not necessarily a drawback — most images you take with this lens are going to be planned out ahead of time and you should have plenty of time to get the focus set how you want. Additionally, I would image that autofocus on a lens like this would be a nightmare for a camera manufacturer to program.
On the plus side, the 24mm lens I rented is one of Canon's best 24mm lenses. Of course the lens tilts and shifts, but when it's not doing that it's simply a regular 24mm lens and the image quality is SUPERB. The lens' aperture goes down to f/3.5 so that means you get an extra half stop of light than you'd normally get, and the glass for this lens was made with quality in mind.
If ever you try out a tilt/shift lens (and you're shooting Canon), I definitely recommend this one. Have fun, be patient and learn how to use the lens before taking it out on big projects and you'll be fine.