Candela per square metre explained

Candela per square metre
Standard:	SI
Quantity:	luminance
Symbol:	cd/m^2
Extralabel:	In SI base units:
Extradata:	cd·m^−2

The candela per square metre (symbol: cd/m²) is the unit of luminance in the International System of Units (SI). The unit is based on the candela, the SI unit of luminous intensity, and the square metre, the SI unit of area.

The nit (symbol: nt) is a non-SI name also used for this unit (1 nt = 1 cd/m²).^[1] The term nit is believed to come from the Latin word, "to shine".^[2]

As a measure of light emitted per unit area, this unit is frequently used to specify the brightness of a display device. The sRGB spec for monitors targets .^[3] Typically, monitors calibrated for SDR broadcast or studio color grading should have a brightness of .^[4] Most consumer desktop liquid crystal displays have luminances of 200 to 300 cd/m².^[5] HDR displays range from around 400 to 2500 cd/m².^[6]

Comparison with other units of luminance

One candela per square metre is equal to:

• 10⁻⁴ stilbs (the CGS unit of luminance)
• π×10⁻⁴ lamberts
• π apostilbs
• 0.292 foot-lamberts
• π×10³ skots
• π×10⁷ brils
• 1 nit

See also

• Orders of magnitude (luminance)
• Photometry (optics)

External links

• IEC 61966-2-1:1999 Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB
• IEC International System of Units zone

Notes and References

1. Book: Vision . Pierre . Buser . Michel . Imbert . MIT Press . 1992 . 978-0-262-02336-8 . 53 . registration . nit luminance. .
2. Book: Astronomical Photometry . RLF . Boyd . Springer . 1992 . 978-0-7923-1653-4 . 9 .
3. Web site: IEC 61966-2-1 . 1999 . Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB . .
4. Web site: 2013-08-13 . ITU-R BT.2035-7 . live . https://web.archive.org/web/20221220125027/https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.2035-0-201307-I!!PDF-E.pdf . 2022-12-20 . 2022-12-20 . A reference viewing environment for evaluation of HDTV program material or completed programmes.
5. Web site: Acer Ferrari One 200 Review – More than a Netbook . Jonathan . Hung . May 3, 2010 . PC Perspective . 2018-01-21.
6. Web site: Cohen . Steven . What is HDR? High dynamic range TVs and formats, explained . 2024-05-08 . Business Insider . en-US.