Vary focus or use focus rail

I am about to try some of the new function in CS4, similar to Helicon Filter and CombineZ....i.e. to have different areas of an object, say a flower, and then combine them to gain greater DOF.

The question I have....is it better to vary the focus for each shot or use a focusing rail with set focus and vary the distance.

My thought is that a rail will change the size of the object as the distance changes.

Secondary question...thoughts/su​ggestions on the software choices, as far as ease of use and quality of the results.

Thanks...

use the rail although most of us just bodily move the camera in as we are not shooting from tripods.

racketman wrote in post #7814196
use the rail although most of us just bodily move the camera in as we are not shooting from tripods.

How do you deal, when blending, with differing object size due to the different distances...of course, this may not be what you would be doing as you are not using a tripod.

John - not sure what the align function does in CS4 but in dedicated stacking progs, the images are automatically re-sized to allow for the FOV changes.

Brian v.