Projector glossary

Categories & form factors

Home cinema projector

A projector built for a light-controlled room: high native contrast, accurate color, quiet, 24p-correct.

Home entertainment / living-room projector

Brighter, less contrast-focused, built to cope with some ambient light.

Ultra-short-throw (UST) / "laser TV"

Sits a few centimetres from the wall and projects upward through a steep aspect mirror.

Short-throw projector

The throw ratio is roughly 0.4–1.0:1, so you get a big image from 1–2 m away.

Portable / lifestyle projector

Battery or USB-C powered, usually has a smart OS, and is often on a gimbal or stand.

Pico / mini projector

Pocket-sized, under about 300 ISO lumens.

Business / education projector

Designed for meeting rooms and classrooms.

Large-venue / installation projector

5,000–40,000+ lumens, interchangeable lenses, edge blending, warping, 24/7 operation, HDBaseT/SDI inputs.

Digital cinema (DCI) projector

Built to the DCI spec and SMPTE standards, using DCI 2K/4K containers and 48 cd/m² (14 fL) reference luminance.

Gaming projector

A marketing label, not a category. It means low input lag modes, 120/240 Hz input and sometimes VRR/ALLM.

Imaging technology

DLP (Digital Light Processing)

Texas Instruments' MEMS technology. A DMD chip carries millions of micro-mirrors that tilt on/off thousands of times per second.

DMD (Digital Micromirror Device)

The DLP chip itself. It is identified by diagonal size and native mirror count.

XPR (Expanded Pixel Resolution)

TI's fast optical actuator. It shifts each mirror's image by half a pixel (2-way) or into four positions (4-way) within one frame, so a sub-4K chip can address 8.3 million "on-screen pixels".

3LCD

Uses three transmissive LCD panels, one each for red, green and blue, combined by a dichroic prism.

LCoS (Liquid Crystal on Silicon)

Reflective liquid-crystal panels, usually three of them.

SXRD

Sony's LCoS implementation. imaging.technology_brand = sxrd

D-ILA

JVC's LCoS implementation. imaging.technology_brand = d-ila

Single-panel LCD

Cheap transmissive LCD with an LED behind it.

e-shift / 4K PRO-UHD / 4K Enhancement / pixel shifting (general)

Vendor names for optical pixel shifting on LCD and LCoS panels.

Native resolution

The number of physical pixels or mirrors on the imaging device, before any shifting.

Addressable / displayed resolution

What appears on screen after pixel shifting, e.g.

Supported (input) resolution

The highest signal the projector will accept.

Rainbow effect (RBE)

Brief red, green and blue fringes seen by some viewers on single-chip DLP with sequential color, especially on high-contrast moving edges.

Screen-door effect (SDE)

A visible grid between pixels, caused by a low fill factor on LCD panels at large image sizes.

Fill factor

The fraction of each pixel's area that emits or reflects light.

Color wheel

A spinning segmented filter in lamp and laser-phosphor DLP.

BrilliantColor

TI's processing for multi-segment wheels.

Convergence / panel alignment

How well the R, G and B images overlap on 3-panel systems (3LCD/LCoS).

Dynamic iris / aperture

A mechanical iris that closes on dark scenes to lower the black floor and raise "dynamic contrast".

Light source dimming / laser dimming

Frame-by-frame modulation of laser or LED output.

Light source

UHP / mercury lamp

The traditional ultra-high-pressure lamp.

Laser phosphor (blue laser + phosphor)

Blue laser diodes excite a yellow phosphor wheel or plate, which produces broadband light that is then filtered, sometimes with a color wheel.

RGB laser / triple laser

Separate red, green and blue lasers. Very wide gamut, often near or above 100% BT.2020 coverage in xy (check the CIE space).

Hybrid (laser + LED)

For example, a blue laser plus red/green LEDs, or an LED array plus laser.

LED

RGB LEDs are sequential on DLP, or white LEDs sit behind LCD.

Light source life

Hours until brightness drops to a stated fraction of initial, per mode.

Eco / light output modes

Preset power levels. Brightness, fan noise and life all vary by mode, so specs must state the mode they were measured in.

Speckle

A grainy, shimmering interference pattern from coherent laser light, most visible on high-gain screens and with RGB laser.

Warm-up / cool-down time

Seconds to full brightness. Lamps take 30–60 s plus cool-down, solid-state is near-instant.

Brightness

Lumen

The SI unit of luminous flux: total visible light output, weighted by the eye's sensitivity curve V(λ).

ANSI lumens

From the withdrawn ANSI/NAPM IT7.228 (1997).

ISO lumens (ISO/IEC 21118)

The current international method: ISO/IEC 21118:2020 light output, measured per its Annex B, which builds on the IEC 61947-1 9-point method.

CVIA lumens

A Chinese group (industry association) standard, 《投影机光输出技术要求和测试方法》, from the China Electronic Video Industry Association (中国电子视像行业协会), ~April 2023.

"LED lumens" / "light source lumens" / "lux" / "peak lumens" ⚠

Non-standard units, typically 2–10× higher than ISO lumens.

Calibrated lumens / measured lumens

Brightness measured by a reviewer in the most accurate (calibrated D65) picture mode.

Color light output (CLO) / color brightness

Brightness of R, G and B measured separately and summed, defined in IDMS/ICDM.

Brightness uniformity

The ratio of the darkest to the brightest of the 9 (or 13) measurement points, as a %.

Nits (cd/m²)

Luminance: light reflected from the screen toward the viewer.

Foot-lambert (fL)

Imperial luminance unit, equal to 3.426 cd/m².

Lux

Illuminance (light falling on a surface).

Contrast & black level

Native contrast (on/off)

Full-white luminance divided by full-black luminance, with the iris and dimming fixed.

Dynamic contrast ⚠

On/off contrast with the dynamic iris or light-source dimming active, often quoted as 1,000,000:1, 3,000,000:1 or "∞".

ANSI contrast (checkerboard / intra-scene)

A 4×4 black/white checkerboard: average white ÷ average black.

ISO contrast

The ISO/IEC 21118 contrast item (full-on/full-off under that standard's conditions).

PISCR (Projected Image System Contrast Ratio)

ANSI/INFOCOMM 3M-2011, an AV-industry system metric that includes the room and the screen.

Black floor / black level

The luminance of a full-black frame in nits.

DLP "grey bars" / dark border

Light spill around the active image on some DLP models.

Intra-scene vs sequential contrast

Sequential contrast compares two different frames (on/off).

Resolution, sharpness & processing

4K UHD vs DCI 4K

UHD is 3840×2160 (16:9). DCI 4K is 4096×2160 (~1.9:1).

1080p / FHD, WUXGA, WXGA, XGA, 720p

Common native resolutions: 1920×1080, 1920×1200 (16:10, business), 1280×800, 1024×768 and 1280×720 respectively.

MTF (Modulation Transfer Function)

The lens's ability to resolve fine detail.

Lens quality / chromatic aberration / focus uniformity

Glass vs plastic elements, lens element count, edge sharpness and CA fringing.

Scaling / upscaling

Converting the input to native resolution.

Frame interpolation (MEMC / "motion smoothing")

Generates intermediate frames to reduce judder, which produces the "soap-opera effect".

24p / 3:2 pulldown / judder

Film is 24 frames/s. A projector that shows 24p at a multiple of 24 Hz (48/72/96/120/144) avoids 3:2 pulldown judder.

Black frame insertion / motion blur reduction

Inserts dark frames to sharpen motion, at the cost of brightness.

Bit depth / 10-bit / 12-bit processing

The processing pipeline's color precision.

Color

Color gamut

The range of chromaticities a projector can reproduce, plotted on a CIE chromaticity diagram.

Rec.709 / BT.709

The HDTV and SDR color space. 100% coverage is the minimum for accurate SDR.

DCI-P3

The cinema color space, used as the HDR mastering container in practice.

BT.2020 / Rec.2020

The UHD/HDR container gamut. Only RGB-laser projectors approach full coverage.

Coverage vs area ⚠

Coverage is the % of the target gamut the projector actually reaches (the intersection).

CIE 1931 xy / CIE 1976 u′v′

Chromaticity coordinate systems. u′v′ is more perceptually uniform, and BT.2100 / ITU tend to report in it.

White point / D65 / correlated color temperature (CCT)

D65 (~6504 K) is the reference white for video.

Delta E (ΔE, ΔE2000, ΔE ITP)

Color error vs reference. ΔE2000 below 1 is roughly imperceptible and below 3 is generally fine.

Gamma / EOTF

The SDR tone curve: gamma 2.2/2.4, or BT.1886 (the reference SDR EOTF).

CMS (color management system)

User-adjustable hue, saturation and luminance per primary and secondary.

Calibration (ISF / THX / Calman)

ISF and THX certify calibration-capable modes.

Filmmaker Mode

A UHD Alliance mode that disables processing and targets the mastering intent.

Metamerism (RGB laser)

Narrow-band RGB lasers can look different to different people, and color meters can disagree with eyes.

HDR

HDR10

PQ (SMPTE ST 2084) EOTF, BT.2020 container, static metadata (MaxCLL/MaxFALL, ST 2086 mastering display data).

HDR10

PQ (SMPTE ST 2084) EOTF, BT.2020 container, static metadata (MaxCLL/MaxFALL, ST 2086 mastering display data).

HLG (Hybrid Log-Gamma)

Backward-compatible broadcast HDR (ARIB STD-B67 / ITU-R BT.2100).

Dolby Vision

Dolby's dynamic-metadata HDR. On projectors since late 2021 (Xiaomi Laser Cinema 2, China), then Formovie, XGIMI Horizon Ultra, Optoma UHC70LV and others.

Tone mapping

Projectors reach about 50–300 nits on screen, while HDR is mastered to 1,000–4,000 nits, so content must be compressed.

MaxCLL / MaxFALL

Maximum content light level and maximum frame-average light level: static HDR metadata the projector can use for tone mapping.

Motion, refresh & gaming

Input lag

The time from signal to display, in ms. It is measured with a Leo Bodnar 1080p60 or 4K60 lag tester, which is the de-facto reviewer method.

High refresh rate (120 Hz / 240 Hz input)

Accepts high frame rates, typically at 1080p rather than 4K.

VRR (Variable Refresh Rate)

HDMI 2.1 VRR, FreeSync and G-Sync compatibility.

ALLM (Auto Low Latency Mode)

HDMI signalling that switches the display to game mode automatically.

Game mode

A picture mode that cuts processing to reduce lag.

Optics & installation (the "will it fit my room?" domain)

Throw ratio

Throw distance ÷ image width. A 1.5:1 projector, for example, needs 3 m of distance for a 2 m-wide image.

Throw distance

Lens-to-screen distance. ISO/IEC 21118 defines it from the screen to the outermost lens element.

Optical zoom ratio

Max ÷ min throw ratio, e.g. 1.6×. Optical zoom keeps all pixels, while digital zoom throws resolution away.

Lens shift

Moves the image vertically or horizontally without tilting the projector or degrading the image.

Offset (fixed)

On projectors without lens shift, the image is projected above (or below) the lens axis by a fixed %.

Keystone correction ⚠

Digital correction for a tilted projector.

Auto keystone / auto focus / screen fit / obstacle avoidance / eye protection

Sensor-assisted setup using ToF, camera or gyroscope.

Lens memory

Stores zoom/focus/shift positions, e.g. to switch between 16:9 and 2.39:1 on a scope screen.

Motorised lens

Powered zoom, focus and shift. optics.motorized_zoom, optics.motorized_focus

Interchangeable lens / lens mount

Installation projectors take swappable lenses.

Anamorphic lens / scope (2.35/2.39:1)

An external anamorphic lens, plus vertical stretch processing, fills a 2.39:1 screen without black bars.

Aperture (f-number) / focal length

Lens specs that some datasheets include. A lower f-number lets more light through.

Image size range

The minimum and maximum diagonal the lens can focus.

Aspect ratio (native)

16:9, 16:10, 4:3 or 17:9 (DCI-shaped). imaging.native_aspect

Mounting orientations

Front, rear, ceiling, floor, portrait, 360° (installation).

Edge blending / warping / stacking

Installation features for combining multiple projectors or projecting onto curved surfaces.

Screens (the other half of the picture)

Screen gain

Reflectivity relative to a matte white reference (1.0, Lambertian), measured per SMPTE RP 94 at 5° intervals.

Half-gain viewing angle

The angle at which luminance falls to 50% of peak.

ALR (ambient-light-rejecting) screen

An optical surface that reflects projector light toward the viewer while absorbing or redirecting off-axis room light.

CLR (ceiling-light-rejecting) / UST screen

A lenticular or Fresnel ALR built for the steep upward light angle of UST projectors.

Grey screen

A low-gain (~0.8) screen that improves perceived black on low-contrast projectors.

Acoustically transparent (AT)

Woven or perforated so speakers can sit behind it.

Tensioned / fixed-frame / motorised / floor-rising

Screen construction types.

Hotspotting / sparkle

Uneven brightness and glittery texture on high-gain or ALR screens.Screens are a second entity type in our catalogue (see the content plan).

Connectivity & control

HDMI version & ports

Count, version (1.4/2.0/2.1), max bandwidth (HDMI 2.0: 18 Gbps; 2.1: up to 48 Gbps, with some chips limited to lower FRL rates such as 40; HDMI 2.2, released June 2025: 96 Gbps), HDCP version (Netflix

ARC / eARC

Sends audio from the projector's built-in apps (or passes it through) to a soundbar or AVR.

HDBaseT

Video, control and power over a single Cat cable for long runs.

USB-C (DisplayPort Alt Mode / PD)

Video in from laptops and phones, and power in on portables.

RS-232 / LAN / IP control / 12 V trigger / IR

Home-automation control. Supported ecosystems include PJLink, Crestron, Control4, Savant and AMX.

Wireless casting

Chromecast built-in, AirPlay 2, Miracast.

Wi-Fi / Bluetooth versions

Wi-Fi 5/6/6E, BT 5.x (for speaker mode or headphones).

Bluetooth speaker mode

Use the projector as a BT speaker. Portable feature.

Smart platform

Smart OS

Google TV, Android TV (certified vs AOSP "uncertified"), Fire TV, webOS, Tizen, VIDAA, Roku, proprietary or none.

Native Netflix ⚠

Netflix certification is the #1 smart-projector question.

Streaming DRM (Widevine L1)

Netflix requires Widevine L1 for HD on Android devices.

Audio

Built-in speakers

Output in watts, channel count, partner brand (Harman Kardon, Bowers & Wilkins, Dynaudio, Yamaha…) and decoders (Dolby Audio, Dolby Atmos, DTS:X, DTS Virtual:X).

Audio out

3.5 mm, optical, ARC/eARC. audio.outputs[]

Noise, power, physical

Fan noise (dB(A))

Usually quoted in eco mode as a sound-pressure figure, often without a stated distance.

Power consumption

Watts in normal, eco and standby. Networked standby matters under EU rules.

Heat output

BTU/h = W × 3.412. Matters for small or closed rooms and hush boxes.

Power supply

Voltage range, internal vs external brick, DC-in.

Battery (portables)

Capacity in Wh or mAh, rated runtime (video mode), charge input.

Dimensions & weight

physical.width_mm, physical.depth_mm, physical.height_mm, physical.weight_kg

Ingress protection (IP rating)

For outdoor and portable models. Dust/water rating such as IP54.

Filter / sealed optics

Dust-sealed optical engine (most laser DLP) vs replaceable filter.

3D

Active-shutter 3D

Synchronised LCD glasses. The sync method is DLP-Link (via the screen), RF (radio) or IR.

3D formats

Frame packing (HDMI 1.4a, used by Blu-ray 3D), side-by-side, top-bottom.

Safety & compliance

IEC 62471-5 risk group (photobiological safety of image projectors)

RG0 (exempt) to RG3. Lamp-equivalent and laser projectors are classified by the risk of staring into the beam.

Laser class (IEC 60825-1)

Consumer laser projectors are typically classified under IEC 62471-5 instead.

FDA laser variance (US)

Under FDA Laser Notice No. 57 (2019), laser-illuminated projectors (LIPs) can't exceed the Class IIIa emission limits of 21 CFR 1040.11(c).

Eye protection sensor

Dims the light source when someone gets close.

Certifications

CE, FCC, UL, Energy Star (where still applicable), TÜV low blue light, Netflix certification, Google TV certification, IMAX Enhanced, THX, ISF.

Commercial & lifecycle

Model number vs regional variant

One projector often has 2–6 model numbers by region: US/EU/UK/JP/CN, color, bundle, retailer exclusives.

Release date / successor / predecessor

For "X vs its predecessor" pages and "is it discontinued?".

MSRP / street price

Launch price per region, plus live retail offers.

Warranty

Years, plus the light-source warranty, which often differs.

Firmware updates

Many improvements come post-launch, e.g. Frame Adapt HDR, Dolby Vision added by firmware.

Marketing traps cheat-sheet (show on site)

What's comparable: summary of axes