i found this site Adaptimax Nikon to Sony PMW-EX3 Adaptor (http://www.adaptimax.com) that lets you put 35mm lenses on a sony ex3. but are these totally different than say a Letus35 adapter? could you still get the same dof or do you need something like a letus to get the great dof?

It won't change the depth of field it just gives you more variety of lenses to choose from. DOF adapters are basically a telecine process, like if you took a camera into a movie theatre and recorded the movie screen. You're purely using the 35mm optics of the lens with its depth of field limitations, etc.. and basically recording a copy of the image it's projecting