# Stilb

Physical unit
Unit name Stilb
Unit symbol ${\ displaystyle \ mathrm {sb}}$ Physical quantity (s) Luminance
Formula symbol ${\ displaystyle L}$ dimension ${\ displaystyle {\ mathsf {N \; L ^ {- 2}}}}$ system CGS system of units
In SI units ${\ displaystyle \ mathrm {1 \, sb = 10 ^ {4} \; {\ frac {cd} {m ^ {2}}}}}$ Named after greek stilbein , "shiny"
Derived from Candela , square meter
See also: Apostilb , Blondel

The stilb ( sb ) is an outdated unit of luminance in non-self-luminous bodies and has not been an official unit of measurement since January 1st, 1978 .

The word is derived from the Greek word stilbein (to shine) and was coined around 1920 by André-Eugène Blondel . While the North American region preferred more pictorial terms such as “ candles per square meter”, the Stilb remained in use in Europe until the Second World War .

The stilb corresponds - with one factor - to the SI unit cd / :

{\ displaystyle {\ begin {aligned} 1 \ \ mathrm {sb} &: = 1 \ \ mathrm {\ frac {cd} {cm ^ {2}}} \\ & = 10 ^ {4} \ \ mathrm { \ frac {cd} {m ^ {2}}} = 10 ^ {4} \, \ mathrm {nt} = 10 ^ {7} \, \ mathrm {Millinit} \\\ Leftrightarrow 10 ^ {- 4} \ \ mathrm {sb} & = 1 \ \ mathrm {\ frac {cd} {m ^ {2}}} \ end {aligned}}} with for the nit . ${\ displaystyle \ mathrm {nt}}$ ## More conversions

The apostilb or blondel was used as a subunit for self-luminous bodies :

{\ displaystyle {\ begin {aligned} 1 \ \ mathrm {asb} = 1 \ mathrm {blondel} & = \ mathrm {{\ frac {1} {\ pi}} {\ frac {cd} {m ^ {2 }}}} && = \ mathrm {{\ frac {10 ^ {- 4}} {\ pi}} \ sb} \\ & \ approx 0 {,} 31831 \ \ mathrm {\ frac {cd} {m ^ {2}}} && = 10 ^ {- 4} \ \ mathrm {la} \\ & \ approx 0 {,} 000031831 \ \ mathrm {\ frac {cd} {cm ^ {2}}} && = \ mathrm {{\ frac {10 ^ {- 4}} {\ pi}} \ {\ frac {cd} {cm ^ {2}}}} \\ & \ approx 0 {,} 000031831 \ \ mathrm {sb} \ end {aligned}}} {\ displaystyle {\ begin {alignedat} {2} \ Leftrightarrow \ mathrm {1 \ sb} & = 10 ^ {4} \ \ pi \ \ mathrm {asb} \\ & = 10 ^ {4} \ \ pi \ \ mathrm {blondel} \\ & = 10 ^ {7} \ \ pi \ \ mathrm {sk} \\ & = \ pi \ cdot \ underbrace {\ left (\ mathrm {{\ frac {1} {\ pi} } {\ frac {cd} {cm ^ {2}}}} \ right)} _ {\ mathrm {la}} \\ & = \ pi \ cdot \ left (\ mathrm {\ frac {ft} {cm} } \ right) ^ {2} \ cdot \ underbrace {\ left (\ mathrm {{\ frac {1} {\ pi}} {\ frac {cd} {ft ^ {2}}}} \ right)} _ {\ mathrm {ft \ la}} ​​&& \ approx 2918 {,} 6 \ \ mathrm {ft \ la} \ end {alignedat}}} With

• ${\ displaystyle \ mathrm {sk}}$ for the scot
• ${\ displaystyle \ mathrm {la}}$ for the Lambert
• ${\ displaystyle \ mathrm {ft}}$ for the foot
• ${\ displaystyle \ mathrm {ft \ la}}$ for the footlambert .

## Individual evidence

1. Measure for measure: the story of imperial, metric, and other units in the Google book search