text: Re: Pay...: Beginners Questions Forum: Digital Photography Review
  Yes, you can cope.
  First, the AF in these modern cameras is fantastic. Your shots won't be out of focus.
  That isn't going to be the problem. The problem will be that everything he wants to be in focus, e.g. the tip of the nose , the near eye, the far eye and the far ear won't be. The DOF profile is about one F stop, maybe a bit more less forgiving. With a crop sensor camera at f/2.8 it was something he didn't have to consider at all. With a full frame at f/1.8 he will have to think about it constantly.
  Go over to the Portraits and People forum where you see it all the time with people who have just moved to full frame.
  But if he want the equivalent depth of field he merely needs to stop down about one stop, and adjust the shutter speed (if movement is not an issue) or ISO to compensate.
  Then he needs to ask himself why is he paying thousands of dollars for a new system if most of the time he is going to be stopping it down one or two stops?
  He would be far better off staying in the system he is in now and just buying a fast lens.
  He has the the freedom to do that, or not, and still gain the benefits of higher resolution.
  What good is paying for freedom you aren't going to use (and he can get it for one tenth the cost simply by buying a faster lens for his existing system).
  Finally, if he has 14mp or more he doesn't need anymore resolution. If he really wants it he can buy a new body and stay in the same system, keep all his lenses, etc.
  The fact is, for the vast majority of photographers, full frame can't be justified.
  It seems more than a little presumptuous of you to be questioning why he wants a new camera. He merely asked about a couple specific things that he perceived to be ramifications of that. He received a number of accurate and helpful responses; yours were, at best, off topic.