Quote Originally Posted by dmm96452
I'm going to be using on the 70-200. While I get that the 1.4 degrades and slows things a little less it also only changes the lens to 98-280. That only actually gains me 80mm. Not sure that will be worth it. Will it?
You're not taking into consideration the cropping factor of your camera body. Since you're shooting with a 20D, you have a 1.6 crop already, which turns your 70-200mm into a 112-320. Adding a 1.4 TC on the end to that gives you a 157-448mm if I did my math right.

Hmm....why haven't I run out to buy one of these yet??