Bounded Zooming Equations

I am working on a camera function that has a zoom feature that is capped and prevents bleeding. I am having problems controlling the boundary while zooming. If I make the equation linear, parts of my stage get cut off too early, but then if I make my equations cubic or logarithmic, I get the basics but then I am shooting in the dark for control and fine tuning.

Any one have any leads, equations, or thoughts? [import]uid: 54716 topic_id: 16893 reply_id: 316893[/import]