The episcope enable object such a books, maps, pictures and three-dimensional models to show up as large clear images on a screen. But it is a fairly cumbersome piece of equipment and not really post-able. Also it produces a great concentration of heat which may destroy-flimsy material. Episcopes projects of p to 10in square, producing sharp colour image measuring 13ft x 13ft. Because only the reflected light is used to illuminate the screen the system is rather inefficient and a complete blackout is necessary.