Learn projectors
Start with the question you're trying to answer. Each guide explains one spec, shows it with an interactive graphic and ranks the projectors we cover by it.
Picture size from distance, or distance from picture size.
Every projector term, from ALR to Xshift.
ISO 21118, IEC 61947 and what “ANSI lumens” really means.
Will it be bright enough?
Lumens, what your screen and room do to them, and why two "3,000 lumen" projectors can look nothing alike.
- ISO lumens
White light output measured by the 9-point method. The screen is split into a 3×3 grid, illuminance is measured at each centre, then averaged and multiplied by image area. It's a production average, and units must reach ≥80% of it.
- LED lumens, lux and other non-standard brightness
- Colour brightness (CLO)
Full red, green and blue fields are each measured, then summed. This captures how bright *colours* are, not just white.
- Nits and foot-lamberts on screen
Estimated on-screen brightness for a given lumen figure, screen size and gain.
- Ambient light and contrast
The light falling on the screen from the room.
- Screen gain
How much brighter the screen is on-axis than a perfect diffuse (Lambertian) white surface.
- ALR and UST screens
Screen technology.
Will it fit my room?
Where the projector goes, how big the picture gets and how much you can move it without losing quality.
- Throw ratio
Projection distance ÷ image width. A range when the lens zooms (e.g. 1.35–2.84:1).
- Optical vs digital zoom
Whether zoom is done with lens elements (optical) or by scaling the image into fewer pixels (digital).
- Lens shift
Shift by remote/motor rather than by dials.
- Keystone and corner correction
Moving each corner (4-point), edge midpoints (8-point) or a full mesh (warp) to fit a screen.
- Screen size and viewing distance
The recommended image size for a viewing distance and content type.
Will the picture look good?
Resolution, contrast, colour and HDR: the specs that decide image quality, and the ones that only look like they do.
- DLP vs 3LCD vs LCoS
The light-valve type that turns light into an image: - DLP: Texas Instruments DMD micromirrors. - 3LCD: three transmissive HTPS panels. - LCoS: reflective liquid crystal on silicon. - Single-panel LCD: the budget transmissive design.
- Native resolution
Physical pixels per imaging device. This is the truth behind any resolution claim.
- Pixel shift (XPR, e-shift, 4K PRO-UHD)
Optically wobbling the image by a fraction of a pixel, faster than the eye can follow, to show more distinct pixel positions than the device has.
- Native contrast
Full-white luminance ÷ full-black luminance, with no dynamic iris or light modulation. This is the true black-level capability of the light valve and optics.
- ANSI (checkerboard) contrast
The average of the 8 white rectangles ÷ the average of the 8 black ones, on a 4×4 checkerboard. This is intra-scene contrast.
- Dynamic contrast and laser dimming
The ratio between the brightest full-white frame and the darkest full-black frame, with the iris or laser dimming active.
- Colour gamut (Rec.709, DCI-P3, BT.2020)
How much of the HD/SDR colour space the projector reproduces.
- Gamut coverage vs area
- HDR formats on projectors
The highest HDR signal accepted, e.g. '4K60 10-bit 4:2:2'.
- HDR tone mapping
How out-of-range HDR is compressed: - static: a fixed curve. - adjustable: a user slider. - dynamic: frame-by-frame analysis.
- Rainbow effect (RBE)
Movies and gaming
Smooth 24p film, low lag for games and the HDMI features that make both work.
Living with it
Noise, lamp and laser life, safety and the apps built in.
- Lamp vs LED vs laser
What generates the light: - lamp: a UHP mercury lamp. - led: RGB LEDs. - laser_phosphor: blue laser exciting a yellow/green phosphor. - laser_rgb: discrete red, green and blue lasers. - hybrid: laser + LED.
- Light source life
What 'end of life' means for the hours figure.
- Fan noise
The total acoustic power emitted, independent of distance. ISO 21118 asks for this in bels.
- Projector eye safety (risk groups and laser class)
The hazard classification of the projected beam, from exempt (RG0) to high risk (RG3).
- Smart projector operating systems
Whether the OS is a licensed, certified build.
- Netflix and Widevine on projectors
The DRM security level. L1 means hardware-backed decryption, which streaming services need for HD and 4K.
Looking for something else? All 72 spec guides