Sorry for this cross-post. No one seems to be able to answer my question, and it is important to me.
Is the Nikon 17-35mm is it parfocal? Is it designed to stay focused while zooming.
Example: focus on a tree at 17mm f/2.8. then zoom to 25mm -- is it designed to remain focused? zoom in to 35mm - still focused?
Im asking about the design of the lens.