I actually once edited RockBottom (the small map inside a fountain) to automatically zoom in and out, so that you have all players on the screen everytime and don't have to zoom by yourself. But with the automatic zooming I got the problem, that it felt pretty "hackly". That had something to do with the "interpolation" I think. The camera zooms one step in and gets slower until it reaches it's determined position. But then It notices "oh I should zoom in some more" because the players position already changed again. And punctually it goes from slow to very fast again, if the player moves fast. That's hard to explain, it just jumps and "sidesteps" around if the player moves fast.

Another question that came up with Zoom: Could it be, that the zoom isn't linear? How is it calculated? How does the players resolution/screensize play in?