Projector Glossary: 80+ common technical terms explained

Airflow

Airflow refers to the flow of air through the projector vents. Cool air comes in and hot air goes out. This is what helps prevent overheating. To allow enough airflow, it’s good to keep at least 18 inches of space beside each projector vent.

Air Mouse

Air Mouse is a feature on Bluetooth remotes that enables you to control the projector by pointing the remote at the screen. When using Air Mouse, a cursor appears on screen, which you can use to hover over options and select them.
See also: Bluetooth Remote

ALPD

ALPD stands for “Advanced Laser Phosphor Display”. It’s the laser engine that powers high-end laser projectors. If you see "ALPD 4.0" or "ALPD 5.0", this denotes the generation. In general, the later the generation, the better the brightness and energy-efficiency.
See also: Laser

ALR

ALR stands for “Ambient Light-Rejecting”. It's a type of screen engineered to block ambient light from affecting a projected image. Using an ALR screen will significantly increase perceived contrast and brightness, especially during the day or with the lights on.
See also: CLR, Fresnel Screen

ANSI

ANSI stands for “American National Standards Institute”. They’re an organization that creates standards for measuring technology, including brightness (Lumens) and contrast. ANSI Lumens and Contrast are more trustworthy than generic measurements, since ANSI has strict requirements to prevent specs from being overinflated.
See also: ANSI Contrast, ANSI Lumens, ISO Lumens, FOFO Contrast, Lumens

ANSI Contrast

ANSI Contrast, or “Checkerboard Contrast”, is a standard measurement of the contrast on a projector or other display. ANSI Contrast is considered trustworthy because it measures the effect of light bleed from having dark and light values on screen at the same time. This is more representative of actual viewing conditions than FOFO Contrast, which measures the minimum and maximum brightness on their own.
See also: Contrast Ratio, FOFO Contrast

Aspect Ratio

Aspect ratio is the ratio between the width and height of your display. For the aspect ratio 16:9, a display that is 16 inches wide will be 9 inches tall. 16:9 is the most common aspect ratio for home theater projectors, but there are several other aspect ratios frequently used for movies and TV. 

Bit Depth

Bit depth is the number of possible shades a projector can display for each color channel. Higher bit depth means smoother color gradients and less color banding. Most HD content is 8-bit (256 shades per channel), while HDR content typically requires 10-bit (1,024 shades per channel) to avoid visible banding.
See also: Color Banding, HDR

Black Level

The black level is the darkest possible value on a projector or other display. The lower the black level, the closer black will be to true black. If the black level is too high, shadows will look gray and all other values will look lighter, too.
See also Contrast Ratio, Dynamic Black, True Black

Bluetooth Remote

Bluetooth remotes pair with your projector using a wireless Bluetooth signal, making it possible to control your projector without pointing the remote directly at the device.
See also: IR Remote

BT.2020

BT.2020 is one of the widest color gamuts used for displays. It reproduces 75.8% of all colors the human eye can see.
See also: Color Gamut, DCI-P3, Rec. 709

Burn-in

Burn-in happens when a display is left on a still image too long without any change. That still image will “burn” into the screen, so that you always see a faint impression of the image no matter what you are watching. This is especially common for LCD and LED displays.
See also: Image Artifact, LCD, LED

Burn Spot

Burn spots are discolored splotches that appear on LCD projectors as a result of chronic overheating. Burn spots may be dark, brown, blue, or even multi-colored, depending on whether the excess heat sears the projector lamp, LCD color panel, or the polarizing filter.
See also: Image Artifact, LCD

CEC

CEC, also known as "HDMI-CEC" or “Consumer Electronics Control”, is a feature that enables you to control your projector using the remote control of another device (such as a Fire TV Stick), and vice-versa.

Chromatic Aberration

Chromatic aberration, or “color fringing”, is a colorful outline around an object on-screen. It appears when the projector lens fails to focus all colors at the same point. In mild cases, this can be fixed by adjusting the projector focus.
See also: Image Artifact

CLR

CLR stands for “Ceiling Light-Rejecting”. It's a type of screen engineered to block ambient light coming from the ceiling. This increases perceived contrast and brightness while the lights are on. Unlike ALR screens, CLR screens are unable to block ambient light coming from the side. For this reason, they offer the best visual experience at night or in a light-controlled room.
See also: ALR, Lenticular Screen

Color Accuracy

Color accuracy is how close the colors you see on-screen are to the actual colors that the projector is trying to replicate. This difference is measured by amount of change, or "delta-E" (ΔE).
See also: Delta-E

Color Banding

Color banding is an image artifact that happens when a projector lacks the color depth required to render a smooth gradient. Instead, the transition between shades appears as distinct, blocky “bands” of color. You can reduce this effect by increasing the color bit signal on your device.
See also: Image Artifact

Color Calibration

Color calibration is the act of adjusting the color balance of the projector so that the colors are more accurate to the source material.
See also: Color Accuracy

Colorspace

A colorspace is a standardized range of colors that can be digitally reproduced by a projector. BT.2020, DCI-P3, and Rec.709 are all examples of colorspaces.
See also BT.2020, DCI-P3, Rec.709,  SDR, HDR

Contrast Ratio

Contrast ratio is the difference between a projector's brightest possible value (white) and its darkest possible value (black). A great contrast ratio is 3,000:1, where the brightest value is 3,000 times brighter than the darkest value.

Contrast Ratio may be measured using the ANSI Contrast or FOFO Contrast method, with ANSI Contrast being more reliable.
See also: ANSI Contrast, Dynamic Contrast, FOFO Contrast, Native Contrast

Dark Spot

Dark spots are small black or gray specks on a projected image. They're caused by dust on the projector lens. Most dark spots can be wiped away with a soft microfiber cloth.
See also: Burn Spot, Image Artifact

DCI-P3

DCI-P3 is a wide color gamut that reproduces 25% more colors than sRGB. It’s wider than Rec.709, but narrower than BT.2020. Read more about color gamut here. DCI-P3 is the most common color gamut used for HDR content. 
See also BT.2020, Colorspace, HDR, Rec. 709

Dead Pixel

Dead pixels are single pixels that won’t respond even after switching to different content or restarting your projector. Usually dead pixels are white, but they can also be black, red, green, or blue.
See also: Image Artifact

Delta-E (ΔE or dE)

ΔE is a measure of color accuracy on a projector or other display, where ΔE=0 is a perfectly accurate color with no change from the source material. The higher this number, the less accurate color reproduction is on that display. A difference of ΔE<3 is considered to be imperceptible to the human eye, although some experts can tell the difference in color when ΔE is as low as 1. 
See also: Color Accuracy

Digital Noise

Digital noise is a grainy film-like effect that can occur in dark scenes. It can be reduced by using the Digital Noise Reduction (DNR) feature on your device.
See also: DNR, Image Artifact

DLP

DLP, or “Digital Light Processing”, is a light projection technology that uses a spinning color wheel to recreate color. Using alternating red, green, and blue filters, DLP projectors create complex colors out of white light. The result is realistic colors with a quick response time. However, compared to LCD and LED, there may be more image artifacts, such as the Rainbow Effect (RBE) and the Screen-Door Effect. 
See also: Image Artifact, LCD, LED, RBE, Screen-Door Effect

DNR

DNR, or “Digital Noise Reduction”, is a feature that reduces graininess in dark scenes by comparing multiple frames to find and remove the stray pixels that don't belong. There are two types of DNR: 2D noise reduction and 3D noise reduction.

2D noise reduction compares two frames at a time. This smooths out the image, but may cause some motion blur, since it can’t track movement over time.

3D Noise reduction compares many frames at once. As a result, you'll get less motion blur but more latency.
See also: Digital Noise, Latency, Motion Blur

Dolby Atmos

Dolby Atmos is a widely popular surround sound technology that integrates with projectors, gaming consoles, and streaming platforms.
See also: dts:X

Dolby Audio

Dolby Audio is an audio-enhancing software that comes built-in to projectors and TVs. Dolby Audio has many features that help to provide clear dialogue and lossless audio quality. It also smooths out volume leveling, making the volume difference less jarring when you switch channels or cut to commercial break.

Dolby Vision

Dolby Vision is an HDR technology that improves color, contrast, and overall detail on your projector through better brightness control.
See also: HDR

Dts:X

dts:X is a surround sound technology that adapts to any speaker layout. Unlike Dolby Atmos, it’s usually limited to select devices and Blu-ray discs. However, fans of dts:X prefer it for its flexibility and low audio compression.
See also: Dolby Atmos

Dynamic Black

Dynamic Black, or "dynamic laser dimming", is a contrast-enhancing feature for laser projectors that selectively dims the laser in dark scenes. By adjusting the amount of light used to create each individual frame, Dynamic Black deepens shadows, preserves colors, and brings out lost details.
See also: Black Level, Dynamic Contrast

Dynamic Contrast

Dynamic contrast is the contrast ratio of a display after it has been enhanced by software. While methods vary, the goal of all dynamic contrast software is the same: deepen shadows and amplify highlights without losing any detail.
See also: Contrast Ratio, Dynamic Black, Dynamic Iris, Native Contrast

Dynamic Iris

Dynamic Iris is a contrast-enhancing feature that selectively widens or narrows the projector lens based on the content on-screen. It widens the lens to allow more light through in bright scenes and narrows the lens to let less light through in dark scenes. This results in higher contrast across all scenes.
See also: Dynamic Contrast

EDID

EDID, or “Extended Display Identification Data”, is information an HDMI device uses to make sure everything is displayed correctly. EDID includes the resolution, colorspace, and manufacturer of your projector or display.
See also: Colorspace

EOTF

EOTF, or “Electro-Optical Transfer Function”, controls how bright a scene looks. It's the formula that your projector uses to turn electrical signal into visible light. Gamma is an older type of EOTF that's only used for SDR displays.
See also: SDR

FOFO Contrast

FOFO Contrast is a method of measuring the contrast ratio of a projector or other display. FOFO stands for “full-on, full-off”, which is a description of how you take the measurement. To measure FOFO Contrast, you measure the brightness of a fully white screen (“full-on”) and compare it to a fully black screen (“full-off”).

FOFO Contrast is considered less trustworthy than other methods of measuring contrast, since it does not represent actual viewing conditions. With normal viewing, light and dark values will be on the screen at the same time, and light areas will bleed into dark areas, lowering the contrast ratio. ANSI Contrast is a more trustworthy way to measure contrast.
See also: ANSI Contrast, Contrast Ratio

Framerate

Framerate is a measure of how many frames per second (fps) there are in a video. The higher the framerate, the smoother the video looks. When the framerate is too low, the video appears to stutter or skip. Most movies are filmed in 24 fps, while video games are typically 60 fps or higher for better responsiveness.
See also: Refresh Rate

Fresnel Screen

Fresnel screens use micro-textures on the surface of the screen to reject ~85% of ambient light. This improves the contrast and visibility of your projector, especially during the day. Fresnel screens are unique among other light-rejecting screens because they’re able to block all ambient light, not just light coming from the ceiling.

This is made possible by the tiny circular ridges that form the screen’s surface. All surfaces pointing outward towards the walls and ceilings are painted black to absorb light coming from that direction. Meanwhile, the surfaces pointed towards the projector are white to amplify and reflect that light towards the viewer.
See also: ALR, Lenticular Screen

Gain / Screen Gain

Screen gain is a measure of how much light is reflected off the screen. The higher the screen gain, the more light is reflected and, as a result, the brighter the projection appears to be.

HDR / HDR10 / HDR10+

HDR, or “high dynamic range”, is a type of video signal with higher color saturation and contrast than standard. There are several types of HDR, including HDR10, HDR10+, Dolby Vision, and HLG.

Although their names are similar, HDR10 and HDR10+ were not developed by the same people. HDR10+ is a newer option with the ability to change picture settings dynamically for individual frames. HDR10, on the other hand, uses static picture settings.
See also: Dolby Vision, HLG, SDR

HLG

HLG, or "hybrid log-gamma", is a type of HDR developed for live broadcasting.
See also: HDR

Hot Spot

A hot spot is a bright spot in the center of your screen. They’re a common issue when combining a UST projector with a high-gain screen.
See also: Image Artifact, Screen Gain, UST

Image Artifact / Image Blemish

Image artifacts and image blemishes are colors, lines, and textures on your projector display that are not supposed to be there. Some are fixable, while others are not.

Though the terms are sometimes used interchangeably, “Image artifact” refers to an  issue inherent to the projector. An example is rainbow effect, which is a result of the refresh rate of the projector not matching the refresh rate of your eyes.

“Image blemish” refers to an issue caused by manufacturing error or improper use. An example is a burn spot, which may be the result of poor cooling systems or leaving the projector on for too long.
See also: Burn-in, Burn Spot, Chromatic Aberration, Color Banding, Dark Spot, Dead Pixel, Digital Noise, Hot Spot, Laser Speckle, Motion Blur, Rainbow Effect, Screen-Door Effect, Soft Corners

IR Remote

IR remotes, or "infrared remotes", are remotes that need to be pointed towards the projector in order to work.
See also: Bluetooth Remote

ISO Lumens

ISO Lumens are a standard measurement of brightness on a projector or other display. ISO stands for "International Organization for Standardization". Like ANSI Lumens, ISO Lumens are measured across 9 screen sections. Unlike ANSI Lumens, ISO Lumens also have strict requirements for testing conditions — including ambient temperature, humidity, and how long the projector has been on when measurements are taken.
See also: ANSI Lumens, Lumens

Keystone Correction

Keystone correction is a method for digitally fixing distortion on a projector.

Lamp Life

Lamp life refers to the typical lifespan of a projector before the light source burns out.

Laser

Laser is a projector light source known for its extremely high vibrance, brightness, and color accuracy. Unlike other light sources, laser projectors use a pure, concentrated beam of light.
See also: DLP, LCD, LED

Laser Speckle

Laser speckle is a TV static-like texture that appears when the laser from your projector hits the surface of the screen and scatters.
See also: Image Artifact

Latency

Latency, sometimes referred to as “lag” or “input lag”, is a measure of the delay between the time it takes for a signal to get from a source (such as a gaming console or streaming stick) to your projector display. Latency is measured in milliseconds.

LCD

LCD, or “liquid crystal display”, is a projector light source known for their high color accuracy and low price. LCD projectors use panels that burn out over time and will need to be replaced more often than their LED or Laser counterparts.
See also: Laser, LED

LED

LED, or “light-emitting diodes”, is a projector light source known for its energy efficiency and long lifespan. LED projectors use clusters of diodes to produce light, which can result in lower brightness than Laser projectors.
See also: Laser, LCD

Lens Shift

Lens shift is a feature that repositions the projected image without moving the projector itself. The lens shifts the image up, down, or side-to-side to give you flexibility on where you can place your proejctor. Lens shift is measured as a percentage of screen height/width (For example, ±10% vertical).
See also: Offset, Keystone Correction

Lenticular Screen

Lenticular screens use a microscopic sawtooth texture on the surface of the screen to reject ambient light coming from the ceiling. This increases contrast when you have the lights on.
See also: CLR, Fresnel Screen

Long Throw

Long throw or “standard throw” is a projector type that needs to be a long distance from the wall in order to create a large image.
See also: Throw Ratio

Lumens

Lumens are a measure of projector brightness. While generic lumens are unregulated, ISO Lumens and ANSI Lumens are variants with strict testing protocols that make it possible to compare brightness between projectors from different brands.
See also: ANSI Lumens, ISO Lumens

MEMC

MEMC, or “motion estimation, motion compensation”, is a feature that reduces motion blur by predicting motion and adding extra frames in between.
See also: Motion Blur

Motion Blur

Motion blur is a blurry streak that follows moving objects in a video. It's especially common in video games and action movies, where movements are quick. Motion blur can be fixed by enabling MEMC in the settings.
See also: Image Artifact, MEMC

Native Contrast

Native contrast is the contrast ratio of a projector or other display without any software enhancements.
See also: Contrast Ratio, Dynamic Contrast

Native Resolution

Native resolution is the resolution supported by a projector before any upscaling. If a projector has a native resolution of 1080p and supports 4K, that means the projector has the pixels of a 1080p projector, but 4K movies and games will still look good.
See also: Upscaling

OSD

OSD, or "on-screen display", is the settings menu overlay you can pull up while you're watching something on your projector.

Offset

Projector offset is the vertical distance between the center of the projector lens and the edge of the projected image. If you know the offset of your projector, you will be able to determine the correct height to mount your screen.

Rec.709

Rec. 709 is the gamut of color used by SDR content. It covers approximately 35.9% of the visible light spectrum, and it’s the gold standard for broadcasting.
See also: Colorspace, SDR

SAE

SAE, or Scene Adapt Engine, a next-generation image processing system developed by NexiGo. Trained on over 50,000 hours of raw movie data, it’s designed to enhance visual quality through intelligent, real-time frame analysis. 

SAE analyses movement and predicts the next frame, using this information to smooth transitions, reduce motion blur, and optimize picture quality. It also increases contrast in dark scenes, bringing out details that were lost in the shadows.
See also: Motion Blur 

Screen Door Effect

Screen door effect is a visible black grid between pixels. This phenomenon is most common for low-resolution and DLP projectors, though it’s less noticeable at smaller screen sizes.
See also: Image Artifact

SDR

SDR, or “standard dynamic range”, is a video signal with industry-standard color and contrast. This is compared to HDR, or “high dynamic range”, which features enhanced color and contrast.
See also: HDR

Short Throw

Short throw is a projector type that can be close to the wall and still create a large image.
See also: Throw Ratio

Soft Corners

Soft corners are unfocused corners of a projector screen, caused by an extreme distance between top and and bottom of the screen. They most commonly appear on UST projectors.
See also: Image Artifact, UST

Spatial Audio / Surround Sound

Spatial audio, or Surround Sound, is an audio feature that makes sound feel like it inhabits a 3-dimensional space. Spatial audio may be a simple left-to-right that you hear when you use headphones or a sound bar. Or it could be surround sound, a multi-speaker setup that creates 360° coverage.

sRGB

sRGB is a standard colorspace for the web, monitors, and printers. It covers a similar range of color to the Rec.709 colorspace.
See also: Colorspace, Rec.709, RGB

Throw Distance

Throw distance is the distance between a projector and the wall or screen that it’s projecting onto. Throw distance is usually used in combination with throw ratio to describe the exact distance the projector needs in order to achieve a certain screen size.
See also: Throw Ratio

Throw Ratio

Throw ratio is the ratio between the projector’s distance from the wall and the width of the projected image. It determines how far the projector needs to be from the screen in order to create the image size you want.
See also: Long Throw, Short Throw, Throw Distance, UST

Tri-Color

Tri-Color is a method of color reproduction in projectors that uses three sources of colored light (RGB). This results in higher color accuracy and lower rainbow effect than traditional color reproduction, which uses a single white light source that passes through multiple color filters.

Tri-color projectors may use laser (tri-color laser), LED (tri-color LED), or a hybrid (such as the tri-LED-laser used by the NexiGo TriVision Ultra).
See also: RGB

True Black

True black is the darkest possible black value. 
See also: Black Level

Upscaling

Upscaling is when a projector alters content in a different resolution to make it look better on-screen. To display low resolution content, projectors often smooth the edges and generate new pixels using AI. To display high resolution content, projectors often use pixel shifting — rapidly shifting pixels around to trick the human eye into seeing a higher resolution image.
See also: Native Resolution

UST

UST, or ultra-short throw, is a projector with a throw ratio so small that the projector only needs to be a few inches from the wall to get a large screen.
See also: Throw Ratio

Zoom

Zoom is a method of shrinking the screen to a smaller size without moving the projector. Though convenient, this feature lowers the overall resolution of your projector.