Kodak's guide to Estimating Luminance and Illuminance using a camera's exposure meter.Knowledgedoor, LLC (2005) Library of Units and Constants: Illuminance Quantity.Archived from the original (PDF) on Decem. ^ 'Formulae for converting to and from astronomy-relevant units' (PDF).'Radiometry and photometry in astronomy FAQ, section 7'.

^ 'Illuminance - Recommended Light Level'.

International Electrotechnical Commission (IEC): International Electrotechnical Vocabulary.

^ a b International Electrotechnical Commission (IEC): International Electrotechnical Vocabulary.

CIE - International Commission on Illumination. CIE S 017:2020 ILV: International Lighting Vocabulary, 2nd edition. The presence of white objects is somewhat discernible under starlight, at 5 ×10 −5 lux, while at the bright end, it is possible to read large text at 10 8 lux, or about 1000 times that of direct sunlight, although this can be very uncomfortable and cause long-lasting afterimages. The human eye is capable of seeing somewhat more than a 2 trillion-fold range. 'Brightness' should never be used for quantitative description, but only for nonquantitative references to physiological sensations and perceptions of light. Illuminance was formerly often called brightness, but this leads to confusion with other uses of the word, such as to mean luminance. The foot-candle is a non-metric unit of illuminance that is used in photography. In the CGS system, the unit of illuminance is the phot, which is equal to 10 000 lux. In SI units illuminance is measured in lux (lx), or equivalently in lumens per square metre ( lm

Luminous emittance is also known as luminous exitance. Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception. In photometry, illuminance is the total luminous flux incident on a surface, per unit area. Illuminance diagram with units and terminology.

Luminous intensity unit