Editing Printer point (section)

In [[photography]], a '''printer point''' is a unit of relative exposure, in printing a negative, equal to a 1/12 of a [[f-number|stop]] or 0.025 Log(base 10) unit (one-fortieth of a decade) of exposure ratio.<ref>[http://www.spectracine.com/product_filmgate.html "Spectra Film Gate Photometer II"]. Spectracine.com. Retrieved April 5, 2012.</ref>

This numbering scheme is used in [[photographic printing]] and [[photographic filter]]s. Printer points were also used to specify [[color timing]] for photochemical [[film processing]], particularly for motion pictures shot on film.<ref>"Film Technology in Post Production" by Dominic Case, 2001, London, UK: Routledge/Taylor & Francis Group {{ISBN|0240516508}}</ref>

Increasing or decreasing the light by twelve points increases or decreases the exposure by a factor of two.  Such adjustments are used for darkness and color adjustment in photographic enlargers, for example.  A one-stop change in the exposure of a negative may require only an adjustment of about 6 to 8 printer points in printing, depending on the [[gamma correction#Photography|gamma]] of the film.<ref>Richard Kirk (2010), [http://www.filmlight.ltd.uk/pdf/whitepapers/FL-TL-TN-0417-StdColourSpaces.pdf Standard Colour Spaces], FilmLight Ltd.</ref>