FD lenses on T2i....anyone?

BobT wrote:

So I'd be no better off using a legacy lens on my EOS-M then? Is such a combination even possible?

Yes that would work. The important thing is knowing the "flange distance" i.e. The distance from the lens mount to the sensor. In the case of EF/EF-S lens mounts this is 44mm and for the FL/FD lenses the required distance is 42mm. Therefore even mounting the lens directly on the lens mount will put it 2mm forward of where it needs to be (any adaptor will just add to this). The effect is the same as adding a 2mm macro tube, the lens will focus closer but will not focus to infinity hence the need for a correction lens in the adaptor.

In the case of the EOS-M the flange distance is only 18mm which means an adaptor such as this from Amazon places the lens an extra 24mm from the mount thus allowing correct lens operation.

So how about using OLympus legacy lenses on my T2i? Would I need an adapter with a lens on that combination as well? Not too excited about expecting poorer IQ from such a combo, though.

Olympus (OM) lenses have a flange distance of 46mm which means they can be used with EOS (EF/EF-S) bodies with a simple adaptor such as this from Amazon. It is worth investing a little extra in a "chipped" adaptor which allows the camera to indicate focus confirmation.

If you already have the lenses the adaptors aren't too expensive and it's worth experimenting. I wouldn't really consider paying out for legacy lenses especially as lens design has improved over the years. It's probably worth putting the money towards a modern lens.

Maybe this idea is a lot more trouble than it's worth? That's why I'm asking.

It's your call. Using a manual lens requires a definite technique. It is best to focus with the lens wide open (shallowest depth of field so most accurate focus, also brightest) then stop down to the required aperture. This is noticeably slower than using a fully automatic lens.

Bob

There is a very useful table of flange distances here:-

http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

Hope this helps

Ian