Get Sigma 24-35mm f/2 DG HSM Art at B&H Photo.
I’ve found that for focus stacking, world-class lens performance saves me a lot of time:
It is my view that my touchup work in the example that follows would have been made easier by a world-class lens like the Zeiss Otus 28mm f/1.4 APO-Distagon, for the reasons I discuss.
This 3-frame focus stack in Making Sharp Images shows performance at f/9 with a single frame versus the focus stack for comparison. It is an excellent example of when focus stacking is beneficial, but perhaps only for a large print.
Images up to 28 megapixels, with large crops.