Canon App Ui Zoom Function

Heres a quick shot of some of the UI. iv based it on the real workings of a canon 7D, purely for looks and that skeuomorphic feel to the app. The two button/zoom panes would slide in and out of the way from left and right sides of the screen to make way for larger use of the viewfinder.

The zoom on the right is based on the zoom grip ring on a canon lens and would feature a turning animation as the user slides up and down the zoom function.