For those still interested in real film projection : Why do not enlarge directly the film with a special projection lens ? This lens should be composed by two parts. In the first stage a high resolution macro lens focuses the frame enlarging , let's say four times, in a virtual frame. Then in the second stage project this virtual frame to screen. In this scenario we can avoid to blowup the film on a larger film format because the larger frame is already there w/o losing quality on printing new film (and saving a "bit" of money by the way). Moreover, to improve the quality of projection, the film may be flood in a oil bath, a sort of wetgate, like high end film to video transfer and diffuse lighting . The drawback could be a very powerfull light source concentrated on a smaller film format that overheat the gate. Could this thing be feasible or already this exists ?