I'm obviously out of my league here but I'd like to ask a Q. :
how much degredation will you get with a 1.4TC on a 300 f2.8 taking pics at f4- 5.6 (with the apc sensor that would be essentially a 600 f4 lens)? I ask because I'm not sure I can justify both a 300 2.8 and a 500 lens right now....
thanks
