I'm getting ready to invest in a 20D. I have a couple of Sigmas and a Tamron for my Rebel 2000 right now, but none quite as fast as I'd like (fastest is 28-80/f3.5-5.6). I really like what I've read about the Sigma 70-200/f2.8, but it's not "made" for digital. Sigma sells an 18-125/f3.5-5.6 DC that is "made" for digital but I'd like something a little faster.
Am I correct in that the image circle is designed to match the size of the image sensor of digital SLR cameras on Sigmas DC? What, if anything, do I lose by not going with a DC?
Thanks.