PROJECTION SURFACES – TYPES
1. Diffusion Surfaces
They reflect light evenly diffusing it into the space with wide viewing angle. The Gain of the diffusion surfaces is very close to 1. The pro- jector installation method (ceiling, table, with optical angle shift) do not change the quality of the picture displayed at the diffusive surface.
2. Reflective Surfaces
They reflect light directionally into the space similar as mirror. Such re- flection characteristics offers higher picture brightness when observed from the direction the light is reflected to, but the viewing angle is limited. Typical Gain values of reflective surfaces are from the range between 1,5 and 3,0. Projection systems with reflective surfaces re- quireesxact positioning of projector, screen and audience.
3. Retro-Reflective Surfaces
They reflect light directionally back to the light source. High picture brightness will be observed from the right direction or the very nar- row viewing angle. Typical Gain values of retro-reflective surfaces are from 2,0 to 2,5. Projection systems with retro-reflective surfaces re- quires projector and audience to be located at the same level and di- rection.
4. Diffusion-Reflective Surfaces
They transmit and diffuse light into the space. High picture brightness is guaranteed at limited viewing angle only. Typi- cal Gain values of diffusion-reflective surfaces are from the range 2,5 to 4.0. Projection systems with diffusion-reflective surfaces requires precise positioning of projector, screen and audience due to very narrow surface viewing angle.