MAX uses an invisible target to auto adjust the zoom,
this might seem annoying,
but without it you would have to face a linear zoom
if the viewport were too far, zoom would be slow
and if the vport were too close, too fast.
there is a override, you have to hold the SHIFT key,
that will move this invisible target together with the viewport.
Another solution is to, just do a Zoom Extent Selected (in my case, the key 'Z' )
this will move the target to the selected object center, resetting the zoom
..this is for perspective vport,
for orthogonal, I think the zoom happens in 2D.