I am debating on what I should save up for next to add to my 50D.
I currently have a 50 1.8, 28-135 and my sigma 10-20 should be here Monday. The kit lens isn't half bad for a kit lens but I am looking for a bit more reach and something of better quality so I have been looking at 70-200's.
So my plan is to sell my 28-135 (and the Pixma Pro9000 I got ) and put that money toward a 70-200 but I am not sure what I should get.
Get a new Sigma 70-200 2.8 or buy a used canon 70-200 f4L or maybe even a used f4LIS (but most likely not)
I want something with fast autofocus mainly. I would obviously prefer the larger aperture but maybe I could make due with the f/4 I just don't want to kick myself later on down the road

