philiplipetz
Veteran
The problem I have with electronic parfocal lenses has to do with the corrections being momentarily visible in the recorded image. Zooming to a new FOV and watching the lens re-focus is not what I want to see in my footage.
There is a third way to maintaining focus during zoom. Have a varifocus lens with predetermined shifts during zoom. Voilà no focus hunting. Much different from constantly refocusing.