Website with images that pan to different sides
Well I can only guess without seeing the code where the DOM is actually accessed but one thing that looks big to me is that you appear to be manipulating each individual element in seperate frames. If you did the calcs in one function for all elements that would be (I believe) one set of reflow calcs set off in the browser rather than per elements-moved.

Basically any time there is a change to the DOM a series of reflow calculations is set off in the browser. I think when say three DOM changes are made in one function call, the browser is aware of all three before it starts doing anything. Whereas with seperate funcs it does that same work multiple times.

How much reflow calculation gets set off for an action on the DOM in any given browser isn't something I'm a real wizard on but IIRC tends to be a fairly crude operation that doesn't necessarily take "out of flow" elements like absolutely positioned containers into consideration. That said, I still tend to find the DOM seems to have an easier time of it when you try to optimize by taking movable elements out of flow first.

If you don't need to support older browsers, look into CSS3 animation approaches. These can drastically improve animation performance since browsers can optimize for actions before they happen.

Barring that, avoid touching the DOM as much as possible in loops. If you must access properties on a DOM element multiple times, don't keep reacquiring it. Assign it to a var, effectively caching that operation (note: might not matter in newer browsers). But actually making changes to the DOM is where you need to optimize the most. Sidestep with pre-set CSS3 animations or follow some of the older-school stuff I've outlined here and we can examine in more depth if needed.