Now business projectors have a resolution of xga (1024×768) or svga (800×600). Virtually all projections except the base permissions are able to demonstrate image with lower resolution and a resolution of a few steps above, using special algorithms stretching and compressing images. Due to the dynamic development of projectors for home cinema more models in this sector is created based on widescreen with a resolution Wide xga (1280×720) or (1024h576), Wide svga (960h540) and Wide vga (858×480). With regard to video standards, most projectors work well in most common color system pal, secam, ntsc 3,58 and ntsc 4,43. Recently, more projections are beginning to support the format hdtv – High Definition Television.
Almost all multimedia projectors have lenses with variable focal distance, which allow you to resize images on the screen without changing the location of the projector. On some projectors focusing is made by hand, on the other lenses are equipped with electric, allows to scale the image from the remote control. Manual focus is usually more accurate, and motorized lens is useful when ceiling mounted. Many multimedia projectors are equipped with built-in audio system (power amplifier and loudspeaker), and outputs to external speakers to provide sound presentations in small and large audiences. Advantages of multimedia projector: the ability to demonstrate the video and computer images, mobile, portable, the demonstration in large classrooms, a demonstration at lit classrooms, support for high permits. Disadvantages: to prepare materials for presentations require a computer or video camera (although it most convenient to show training videos) Episkopi where they should save time, Bishop seem a godsend. Episkopi can display opaque documents.
Do not need to prepare in advance. Projecting photographs, flyers, brochures, advertisements from magazines to the big screen permanently retain the impression of presentation. Scientific and business scope is the main area of Bishop: demonstration of the on-screen instructions, documents, graphs and charts to increase attention to the subject of the presentation and increases the degree of perception of information. Dignity Bishop: ease of use, ease of material selection Disadvantages: use in small rooms, the impossibility of making written comments Overhead Projectors Traditional projection equipment are overhead projectors. The first overhead projectors appeared in 1944 and has since been widely used in scientific conferences and in schools. Overhead projectors are designed to demonstrate the image applied to the transparent film. The image on transparent film can be applied in several ways: by using special marker pens, printed on a printer with a copier. Advantages of overhead projectors: the ease and speed of training materials, the use of illustrative materials in any sequence, the ability to display the image Disadvantages: most used in films intended for a particular type of office equipment or handwriting, but there are universal film.