View source for Template:SI light units

{{anchor|table-si-photometry-units}}
{| class="wikitable plainrowheaders"
|+ {{navbar-header |1={{resize|130%|{{#if:{{{1|}}}|Table&nbsp;{{{1}}}.&nbsp;}}SI photometry quantities}}|2=SI light units}}
|- 
! scope="col" colspan="2" | Quantity
! scope="col" colspan="2" | Unit
! scope="col" rowspan="2" | Dimension<br>{{#tag:ref|The symbols in this column denote [[Dimensional analysis#Definition|dimensions]]; "'''L'''", "'''T'''" and "'''J'''" are for length, time and luminous intensity respectively, not the symbols for the [[Unit of measurement|units]] litre, tesla and joule.|group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-dimension-symbol}}<!-- [[http://www.bipm.org/utils/common/pdf/si_brochure_8.pdf]] [[http://www.ptb.de/cms/fileadmin/internet/publikationen/DasInternationaleEinheitensystem.pdf]] -->
! scope="col"  rowspan="2" | Notes
|-
! scope="col" | Name
! scope="col" | Symbol{{#tag:ref|[[Standards organization]]s recommend that photometric quantities be denoted with a subscript "v" (for "visual") to avoid confusion with radiometric or [[photon]] quantities. For example: ''USA Standard Letter Symbols for Illuminating Engineering'' USAS Z7.1-1967, Y10.18-1967|group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-suffix-v}}
! scope="col" | Name
! scope="col" | Symbol
|- 
! scope="row" | [[Luminous energy]]
| {{math|''Q''{{sub|v}}}}{{#tag:ref|Alternative symbols sometimes seen: {{mvar|W}} for luminous energy, {{mvar|P}} or {{mvar|F}} for luminous flux, and {{mvar|ρ}} for luminous efficacy of a source.|group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-alternative-symbol-photometric}}<!-- Luminous energy alternatives: Q is used throughout literature. Palmer recommends W (typo for E?) as acceptable alternative. -->
| [[lumen second]]
| [[lumen (unit)|lm]]⋅s
| '''T'''⋅'''J'''<!-- STOP! J does not stand for Joules here! This column is dimensions, not units!-->
| The lumen second is sometimes called the ''talbot''.
|- 
! scope="row" | [[Luminous flux]], luminous power
| {{math|Φ{{sub|[[Luminosity function|v]]}}}}{{#tag:ref||group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-alternative-symbol-photometric}}<!-- Luminous flux alternatives: Phi_v is used throughout the literature, Palmer uses Phi_p as well, but recommends P as acceptable alternative and uses F in HTML docs. P is used in Slovakian WP, F is still partially used in English WP. -->
| [[lumen (unit)|lumen]] (=&nbsp;candela [[steradian]])
| lm (=&nbsp;cd⋅sr)
| '''J'''<!-- STOP! J does not stand for Joules here! This column is dimensions, not units!-->
| Luminous energy per unit time
|- 
! scope="row" | [[Luminous intensity]]
| {{math|''I''{{sub|v}}}}
| [[candela]] (=&nbsp;lumen per steradian)
| [[candela|cd]] (=&nbsp;lm/sr)
| '''J'''<!-- STOP! J does not stand for Joules here! This column is dimensions, not units!-->
| Luminous flux per unit [[solid angle]]
|- 
! scope="row" | [[Luminance]]
| {{math|''L''{{sub|v}}}}
| [[candela per square metre]]
| cd/m{{sup|2}} (=&nbsp;lm/(sr⋅m{{sup|2}}))
| '''L'''{{sup|−2}}⋅'''J'''
| Luminous flux per unit solid angle per unit ''projected'' source area. The candela per square metre is sometimes called the ''[[nit (unit)|nit]]''.
|- 
! scope="row" | [[Illuminance]]
| {{math|''E''{{sub|v}}}}
| [[lux]] (=&nbsp;lumen per square metre)
| [[lux|lx]] (=&nbsp;lm/m{{sup|2}})
| '''L'''{{sup|−2}}⋅'''J'''
| Luminous flux ''incident'' on a surface
|-
! scope="row" | [[Luminous exitance]], luminous emittance
| {{math|''M''{{sub|v}}}}
| lumen per square metre<!-- lux is defined as lm/m2 but not used for luminous exitance -->
| lm/m{{sup|2}}
| '''L'''{{sup|−2}}⋅'''J'''
| Luminous flux ''emitted'' from a surface
|- 
! scope="row" | [[Luminous exposure]]
| {{math|''H''{{sub|v}}}}
| [[lux second]]
| lx⋅s
| '''L'''{{sup|−2}}⋅'''T'''⋅'''J'''
| Time-integrated illuminance
|- 
! scope="row" | Luminous energy density
| {{math|''ω''{{sub|v}}}}
| lumen second per cubic metre
| lm⋅s/m{{sup|3}}
| '''L'''{{sup|−3}}⋅'''T'''⋅'''J'''
| 
|- 
! scope="row" | [[Luminous efficacy]] (of radiation)
| {{math|''K''}}
| lumen per [[watt]]
| lm/[[watt|W]]
| '''M'''{{sup|−1}}⋅'''L'''{{sup|−2}}⋅'''T'''{{sup|3}}⋅'''J'''
| Ratio of luminous flux to [[radiant flux]] 
|- 
! scope="row" | [[Luminous efficacy]] (of a source)
| {{mvar|η}}{{#tag:ref||group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-alternative-symbol-photometric}}<!-- Examples of usage: eta seems to be in general use, rho has been seen in Slovakian WP -->
| lumen per [[watt]]
| lm/[[watt|W]]
| '''M'''{{sup|−1}}⋅'''L'''{{sup|−2}}⋅'''T'''{{sup|3}}⋅'''J'''
| Ratio of luminous flux to power consumption
|- 
! scope="row" | [[Luminous efficiency]], luminous coefficient
| {{mvar|V}}
| 
| 
| '''1'''
| Luminous efficacy normalized by the maximum possible efficacy
|- 
| style="text-align:center;" colspan=6 | See also: {{hlist|class=inline|[[SI]]|[[Photometry (optics)|Photometry]]|[[Radiometry]]{{#if:{{{2|}}}|{{!}}([[{{#ifeq:{{{2}}}|self||Radiometry}}#table-si-radiometry-units{{!}}Compare]])}}}}
|}{{#if:{{{3|}}}||{{Reflist|group=nb}}}}<noinclude>

{{documentation}}

<!-- Add cats and interwikis to the /doc subpage, not here! -->

</noinclude>