The CineGrey 3D (AT)/CineGrey 4D (AT)/CineGrey 5D are angular reflective front projection materials that reflect at the mirror-opposite angle. If an ultra-short throw projector is used, the material will reflect the steep narrow light and reflect it upwards instead of to the viewer’s eye level. Image shows how a UST projector with CineGrey 3D looks like in a room with ambient light. Image shows how a UST projector with CineGrey 3D looks like in a room with lights turned off The image appears to look good, but is still reflecting the projector light upwards and causing a hotspot in the middle of the image. Overhead lights are being absorbed/reflected off the material while providing great color saturation, image brightness, and black levels for a contrast rich presentation. Model# AR100DHD3 – CineGrey 3D EDGE FREE 100” Diagonal 16:9 Fixed Frame with JVC LX-NZ3B 4K HDR Laser Projector Image shows how good a performance can be obtained using a standard throw projector with ceiling lights above