Quote Originally Posted by Cathathome
Cool!

Can you elaborate on the adapter part? I've been sticking to Canon EF or Canon mount lenses only, believing this is my only option. I could be persuaded to try different lenses if they could be made compatible, especially with future cameras. My XT won't last forever, eh? . Plus I keep looking at the old film Rebel collecting dust...hmm, full frame!
Hi Cath,

The Canon EF lens mount is blessed with a short flange distance, which gives you the ability to adapt lots of other lenses, including, Nikon, Olympus, M42 screwmount, Contax, and I'm sure there's more. There is a catch though...actually, a couple of catches. You have to buy the appropriate adapter, and even then you will loose autofocus and auto-aperture function. You may also loose certain metering modes.

The autofocus issue can be dealt with in two ways. You can swap out your focus screen for one that is better suited for manually focusing (google Katz eye or Haoda fu). Or, you can get an adapter that has a chip on it and allows focus confirmation. There are advantages and disadvantages to each. I just ordered a focus confirm adapter, but I haven't tried it yet.

The lose of auto-aperture function might be the biggest issue for most people. It means you have to focus with the aperture wide open, so you have enough light to see, then stop the aperture down to where you want it to take a meter reading and to take a shot. It's not practical for fast moving subject matter or quick shooting in general, but it works.

The metering issue is not a big deal. Even the plane metal adapters will still allow center weighted and spot metering modes, but if you want to use the evaluative mode, there are only certain chipped adapters that allow that. Even then, some people report exposure problems. You may have to apply some exposure compensation, but it shouldn't be a big deal. I actually prefer center weighted most of the time anyway.

It's not a perfect solution, but if you have some old manual focus lenses, or you want to save some money and don't mind the hassle, there are tons of lens options for your Canon.

Paul