I've recently purchased a 6d. It's a great camera and I love the look it has, but I'm having all sorts of troubles focusing. I mainly do portraits, and that requires me to consitently hit sharp focus on the eyes. For the life of me I can't do that. I'll focus on the eye using the middle autofocus point and then will recompose and take the picture, but it still won't work. It works half the time, but that's not good enough at all. It's been driving me crazy and I can't confidently go into a shoot. I'm getting paid for shoots also, so this isn't acceptable.
Can you post some examples? I would like to see the missed focus shots and where exactly you originally focused before you recomposed.
Someone mentioned above that ' you can never get precise focus using focus and recompose'.
This is nonsense. I do it all the time with my 6D, I did it all the time with my 600D. It is a very common practice used by most all photographers, professionals and amateurs alike with perfect success.
It almost sounds like you have the camera set to AI Servo.....so when you try to recompose it will focus on the new target.
It works if you recompose and take, let's say, one step backwards. Or if your camera front focus. Or if your DOF is enough.
It is also possible that your af needs a calibration. You can try it out using a tripode and a high contrast thingy (maybe a bare code) two three meters away.
You can start with focusing with center point through the viewfinder 5-8 times. Unfocus between every shoot. When you are done you take one shoot in live view. If you get a sharper image on the high contrast thingy with live view, then you will need adjust your af. The best way is to send the camera and lenses to calibration. The second best is to self try to microadjust the af from the menu.