Chris: It's called the "digital multiplying factor". Because the array inside most digital cameras (the part that actually takes the picture) is smaller than a standard 35mm film frame (which is what the lenses were made to work with) the focal length of the lens attached is increased. It's kind of a misnomer. The camera doesn't actually multiply the image, it is cropping what the lens sees which gives the effect of a longer focal length. Blah blah blah... :) For the 300D, that means that if you have a film lens that's marked at 50mm, when you put it on the 300D the image you take with it looks like it was taken with an 80mm lens. Bad thing is you need a really wide angle lens to get shots that look like it was taken with a standard wide angle. The good part is if you shoot with long focal lengths, you get longer ones with the 300d (200mm becoms a 320mm). There's also an interesting theory I've been reading. They call it the "Sweet Spot Effect". Because the image that falls onto the digital array is from the center of the lens and the best part of most lenses is the center (it's usually around the edges that you start to get distortion and bad optical quality on cheaper lenses); the DSLR may have the added effect of making the lens perform "better". -=>DOnald