Thanks guys for the comments on my steam shovel photo! I recently got a really good deal on a Tamron 11-18mm lens for my Canon 400D, and have been taking a lot of photos using mostly this lens. As some of you may know, in the past I've done a lot of photography with film cameras using a 28mm Vivitar lens that I modified with a pinhole aperture. It allowed me to get super close to the models for a very realistic look.
Well this lens does fit on my digital camera, but does not produce the same result. The sensors on Canon digitals are only 60% the size of a 35mm film frame, meaning you only get the center 60% of what a normal lens sees. That results in my 28mm lens being about a 56mm lens, a very mild telephoto instead of a wide angle. Wide angle lenses give better depth of focus, so the pinhole lens doesn't do much on the digital camera.
Now the new 11-18mm lens at its widest is equal to a 17mm lens on a film camera, its an extreme wide angle, which gives great depth of focus. While its closest focusing distance is 9 inches, by using its smallest aperture of f/22, the zone of focus will be closer than the 9 inches.
Here's how the steam shovel photos were taken, on a styrofoam diorama base sitting on a small table I made for photography. Since the lens takes in so much, I'm using the wall that I painted dark blue and added clouds.
Lotsa fun!