I am amazed at how many ask 'what should I buy' questions here. I don't mean that there is a tech question, which I'd understand, but a desire one like which is better - a 6D or a 7D? I wonder that people think others, here on the Internet, can decide their lives better then they can themselves.
I figure in the name of pre-addressing some of these questions, I"d start an FAQ. I heartily invite others to add to the FAQ.
Q. What is the difference between a 24-70 f2.8 and a 24-105 f4 lens?
A. 1.2 and 35.
Q. Which is better, the 6D or the 7D?
A. The 6D. The fewer D's the better all the way down to the 1.
Q. Should I buy a FF or a crop sensor?
A. If you are a farmer, you need a crop sensor. Else the FF.
Q. Do I need a 5D3 or will my Rebel still work?
A. Press the button at the top right of the Rebel. If you hear a clicky noise the Rebel is still working.
Q. I have the 18-55 kit lens. What should be my next lens?
A. Stick with the 18-55. If you get another lens, it won't work unless you take the 18-55 off first which will get dust on your sensor. Then you are finished.
Q. Do I need a long lens for bird snaps?
A. Only if you plan on snapping live birds.
Q. I won't want to use RAW. Must I?
A. No! Remember, that RAW spelled backwards is WAR! Peaceful people everywhere should avoid it if at all possible! Let's make 2013 RAW free.