Hi Guys, Sorry If this question sounds dumb, but please humor me. I am waiting for the Sigma 150-500mm to use with my 40D, but someone mentioned that It backfocuses. What exactly Is backfocusing when shooting birds. I hope my sigma doesnt do that..
Thankyou guys.
Sean..
Backfocusing means that the AF ends up behind your subject as opposed to right on it. I don't think you are going to find that this always happens with this lens but it does happen on occasion with any lens.
It is easy enough to test. Set up a good target ( a $5 bill works well), use a tripod on good light and take a few shots at various f-stops. If it looks at all soft, try the same thing using manual focus. If the AF is not focusing correctly (Back or front focus) the manual focus will be sharper.
Chances are you will have no problem, but if you do with the Sigma only, then talk to Sigma. My understanding is that they are willing to calibrate their lens to fit your camera.
Hi Harold, Thanks for that. Will give It a try when my lens arrives (Sometime soon I hope).
Sean.