Glossary – projection screen terms from A to Z

0–9 V A B C D M F E S G H K T L P Q R U I Z

1:1: Square format. It can display images from projectors with different aspect ratios – the unused part of the screen is simply left blank. Found in education and with older projectors.
4:3: An aspect ratio of approx. 1.33:1, typical of older projectors and documents. Today used mainly where content in this format is shown.
4K Ultra HD: A resolution of approx. 3840 × 2160 pixels in 16:9. With a 4K image, small irregularities in the fabric are more visible, so a flat surface matters. ADEO embossed fabrics have a texture compatible with 4K Ultra HD.
16:9: An aspect ratio of approx. 1.78:1 – the standard for TV, streamed films, games and most Full HD and 4K projectors. The most common choice for home cinema and living rooms.
16:10: An aspect ratio of 1.6:1, native to WUXGA (1920 × 1200) business projectors and many laptops. Recommended for meeting rooms, training rooms and classrooms. See 16:9 or 2.35:1.
Velvet (velvet frame): Black velvet covering on the screen frame, e.g. on Plano models. It absorbs light spilling beyond the image and visually sharpens edge contrast.
ALR (Ambient Light Rejecting): A fabric that rejects ambient light: it reflects projector light towards the audience while largely suppressing light from other directions (windows, lamps). In the ADEO range this is Ambient Grey 2 – for standard and short-throw projectors only, not UST. See ALR and grey screens.
Biformat: A motorised screen with two fabrics in one case – e.g. two aspect ratios or two different surfaces (white and acoustic). See ADEO motorised screens.
Black drop: A black strip of fabric above the image, between the case and the top edge of the projection surface. Its length lets you lower the image so that the bottom edge sits at the right height, even when the screen hangs high up near the ceiling.
CE (declaration of conformity): A marking confirming that a product meets the requirements in force in the European Union. Every ADEO screen has a CE declaration – worth requiring in public procurement.
ChromaKey: A colour keying technique in video: a uniform green background is replaced by another image in software. ADEO offers a ChromaKey Green RAL 6038 backdrop in roller screens – it is a recording backdrop, not a projection surface. See ChromaKey green screen.
CTS (Constant Tensio System): A tensioning system in which hinged counterweights pull rigid cables running through eyelets on the sides of the fabric. It provides constant self-tensioning, and the eyelets are bonded and invisible from the front.
DCI: The digital cinema standard. DCI 4K resolution is 4096 × 2160 pixels, which corresponds to an aspect ratio of approx. 1.9:1 – which is why some cinema screens and custom-size surfaces are also offered in 1.89:1.
Bottom bar (weight bar): The bar at the bottom of a roller screen's fabric that weights and straightens it. On some ADEO models it closes the case when the screen is rolled up, protecting the fabric from dust.
Motorised screen: A screen rolled into its case by a 230 V tubular motor, operated by a wall switch, remote control or the room's control system. After the presentation the wall is clear. See motorised screens.
Fixed-frame screen: Fabric stretched over a rigid, permanently mounted frame. It gives the flattest surface, which makes it the first choice for a dedicated cinema room, ALR fabrics and UST projectors. See fixed-frame screens.
Curved screen: A screen with an arched surface which, with wide cinema formats, increases immersion and evens out the viewer's distance to the centre and edges of the image. See curved or flat screen.
Eyelets: Metal eyelets around the edge of the projection surface, through which elastic cords are threaded to fix the fabric to a frame or truss. See Eyelets.
Floating Tab: A side-tensioning system used on models such as OnSuperior, InSuperior, Max One and Max Inceel. It keeps a roller screen's surface flat, including with ALR and acoustic fabrics.
Floating Tensio (FTS, MFTS): A tensioning system with a double bottom bar and two weights: one tensions the fabric vertically, the other – via cables – horizontally. MFTS (Max Floating Tensio) is the version for large screens.
Aspect ratio: The ratio of image width to height, e.g. 16:9 (1.78), 16:10 (1.6), 4:3 (1.33), 2.35:1. The screen's aspect ratio is chosen to match the projector's native format and the content you watch.
Scope format (2.35–2.40:1): The wide format of cinema films. A Scope screen shows a film without black bars at the top and bottom, but requires a projector with lens memory or an anamorphic lens. See 16:9 or 2.35:1.
Front Roll: A rolling method in which the fabric comes out of the front of the case. Useful when the screen hangs close to a wall or obstacle and the fabric needs to clear it.
Gain: Screen brightness compared with a reference matte white surface (gain 1.0). Gain above 1 gives a brighter image on axis but usually a narrower viewing angle; below 1 – a darker image and better blacks. See screen gain and viewing angle.
Hot-spot: A brighter patch in the centre of the image, most often seen on high-gain surfaces or with rear projection. Wide-angle matte fabrics such as Reference White 2 do not produce a hot-spot.
Case: The housing of a roller screen containing the roller with the fabric and the motor. The case is wider than the image – take it into account when planning installation.
Viewing angle: The range of angles within which the image keeps acceptable brightness. Matte fabrics offer approx. 180°, ALR Ambient Grey 2 approx. 60°. The manufacturer recommends that viewers sit within 45° of the projection axis.
Fire rating: A classification of how a material reacts to fire. ADEO surfaces are rated B1, M1 or M2 – depending on the fabric. In public buildings it is worth requiring a document confirming the rating.
Contrast: The ratio between the brightest white and the darkest black on the screen. In practice ambient light reduces it most, which is why grey and ALR fabrics are used in bright rooms.
Keystone correction: Digital straightening of the image when the projector is not square to the screen. It reduces effective resolution, so it is better to place the projector on the screen axis or use lens shift.
Truss: An aluminium stage structure to which fixed-frame screens, quick-fold surfaces and also motorised screens (with special clamps) are fixed. See screens for events.
Lens shift: Mechanical shifting of the image vertically or horizontally without moving the projector and without loss of quality. It makes it easier to fit the image to the screen when the projector cannot hang exactly level with the centre of the image.
Lumen (ANSI): The unit of a projector's light output. The larger the screen, the lower the fabric gain and the more light in the room, the more lumens you need for a bright image.
Masking: Covering the unused part of the screen with black material so that an image in a different format (e.g. 2.35:1 on a 16:9 screen) has crisp black matte edges. See Aspect ratio: 16:9 or 2.35:1.
Moiré: A wavy interference pattern that can appear when the image's pixel grid overlaps the regular perforation of an acoustic fabric. The risk depends on the perforation size, the image size and the viewing distance.
Multiformat: A motorised screen with automatic format masking – one screen for 16:9 content and films in cinema format. See the aspect ratio guide.
Anamorphic lens: An attachment for the projector lens that stretches the image horizontally to fill a 2.35–2.40:1 Scope screen with the full resolution of the imaging chip. Requires an anamorphic mode in the projector.
Throw distance: The distance from the projector lens to the screen. Together with the throw ratio it determines the image width: width = throw distance ÷ throw ratio.
Perforation: Tiny holes in an acoustic fabric that let sound pass through from speakers placed behind the screen. ADEO uses 0.5 mm perforation (home cinema, meeting rooms) and 1.3 mm (cinemas, theatres). See acoustic screen.
Quick-fold surface: Made-to-measure projection fabric without its own frame, fixed with elastic cords or through eyelets to a truss, stage frame or building structure. See quick-fold surfaces.
Front projection: A set-up in which the projector and the audience are on the same side of the screen and the image is reflected off the surface. The most common way of projecting.
Rear projection: The projector stands behind the screen and shines through a translucent fabric. It eliminates presenter shadows and hides the projector, but requires space behind the screen and a mirrored image. See rear projection.
Diagonal: The distance between opposite corners of the image, usually given in inches (1″ = 2.54 cm). Without the aspect ratio it does not define the width or height of the image. See the diagonal size table.
PSS (Personal Screen System): ADEO's production system in which every screen is made to measure and the fabric is cut by a CAD-controlled plotter.
Black masking border: A black matte strip around the image area. It defines a sharp image edge, absorbs light spilling beyond the screen and improves perceived contrast. On ADEO screens the border edges are welded, not painted.
Reverse Roll: Fabric wound onto the roller the opposite way to standard, so that it drops on the other side of the roller. This changes the distance between the surface and the wall – useful e.g. with a window sill or skirting below the screen.
RS232: A serial communication interface used by room control systems to send commands to AV devices. A screen can be controlled via RS232 through a control interface. See screen control.
Somfy io (io-homecontrol): A motor with two-way io-homecontrol radio communication, operated by remote control and compatible with many smart home systems. An option available on some ADEO models.
ST (standard and short-throw projector): A projector whose throw distance is at least half the image width. Fabrics such as ALR Ambient Grey 2 are designed for these projectors.
Sweet spot: The position from which picture and sound are perceived best – usually on the screen axis, at a distance matched to its size. According to the manufacturer, in home cinema the image height is approx. 1/2.5 of the distance from the main seat (Full HD and better).
Tensio (side tensioning): A family of side-tensioning systems for roller screens: Tensio Classic, CTS, Floating Tensio. They keep the surface flat, which matters with 4K, ALR fabrics and UST projectors. See tensioned Tensio screens.
Tensio Classic: The simplest tensioning system: two elastic cords running from the weight bar through eyelets on the sides of the fabric. Available on models such as Rugby and Inceel.
Throw ratio: The ratio of throw distance to image width. A projector with a throw ratio of 1.5 placed 4.5 m from the screen gives an image 3 m wide. See how to match a screen to a projector.
Acoustic fabric: A perforated, sound-transparent fabric that allows speakers to be placed behind the screen. In the ADEO range: Reference White 2 Acoustik, Vision Acoustik and Vision Macro Acoustik, among others. See screen fabrics.
Embossed fabric: A surface with a fine embossed texture that diffuses light evenly. On ADEO screens it provides definition compatible with 4K Ultra HD.
Extension bracket: A component that moves the screen away from the wall or lowers it from the ceiling. ADEO offers extensions of 300 mm (up to 180 kg per bracket), 450 mm (up to 120 kg), 600 mm (up to 90 kg) and 750 mm (up to 70 kg), among others. See accessories.
UST (ultra-short-throw projector): A projector placed right below the screen, whose throw distance is less than half the image width. It strongly accentuates any waves in the fabric, so it needs a fixed-frame or tensioned screen and Reference Grey 2 or Ambient Grey fabric. See screen for a UST projector.
12 V trigger: A voltage signal from the projector that automatically lowers the screen when the projector is switched on and rolls it up when it is switched off. Requires a control interface or a module with a trigger input.
In-ceiling installation: Fitting the screen case into a suspended ceiling – when rolled up, only a narrow slot is visible. See in-ceiling screens and the guide.
Zoom method (zoom for Scope): A way of showing 2.35:1 films without an anamorphic lens: the projector enlarges the image with its zoom so that the film fills the width of the Scope screen and the black bars fall outside the surface. Some projectors store lens settings for different formats.