Focusing somewhere and then moving camera

Often it is said that one should focus on eyes of wild animals.

But say I focused on a bull's eye. Now if my frame, I could only see part of its body. If I now need to pan the camera to fit entire body, how can I still maintain focus in eyes (which does not fall in any focus points anymore)?

Dont know about your camera but half pressure on the shutter button normally locks focus and exposure,

mike

Read up on the options for programing your AE-L/AF-L button. By default, it locks both exposure and focus, but you can change what it does. Also experiment with single point focus and moving the focus point around to suit. That may work for you in some situations.

2 easy ways - Focus lock works but so does turning off the AF on the lens. But if you do more than just pan, like zoom in/out, you have to refocus.

Not too mention the dark art of... Manual Focus.

I think the OP may be referring to the way the focus plane shifts as you pan the camera to recompose. If you have an extremely narrow depth of field and pan significantly, it could drive what you focused on out of focus. Other than manual focus, stopping down for more DOF, or using one of the outermost focus points so you don't have to recompose as much, I can't think of anything else.