I don't get one thing right. Minimum focus distance for 70-200 is 1.2m, but when you use 500D on it working distance is 50cm. Does this mean no AF?
Can somebody describe me workflow with 500D on 70-200? I mean, do I have to put my subject 50cm from the lens and that's all I can get?
I just got one recently, and was surprised at how it works. It focuses at 50cm, and give you a little bit of leeway since you can still move your focus ring to focus slightly closer or farther away. So basically 50cm plus or minus a little bit. So your framing is very limited unless you use a zoom lens, which will let you increase or decrease the size of the subject in the viewfinder.
Af does work still, but it's tough to get it accurate due to the high magnification (I often use it on a 400mm with a 1.4x), and only makes a difference in the 50cm range. You won't be able to AF on anything outside of this range.
It sounds limiting, but I love it. I don't want to buy a dedicated macro lens, and this little piece of equipment is amazing. Even got an adapter to fit it on my 100mm F2.0 to get closer with it if I need to.