Apostilb
= Apostilb
{wiki=Apostilb}
An apostilb is a unit of measurement for luminous intensity, specifically in photometry. It is defined as equivalent to one lumen per steradian. The term "apostilb" can sometimes be seen as a non-SI (International System of Units) unit, and its use is less common compared to other measurements like the candela, which is the standard unit of luminous intensity in the SI system.