| Light Value |
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Information AboutLight Value |
| CATEGORIES ABOUT LIGHT VALUE | |
| science of photography | |
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It is a base 2 Logarithm ic scale, and an increase of one corresponds to half the amount of light admitted. The traditional definition is: LV 10 = 10 Candela s per Square Foot = 107.64 cd/m&2 To obtain correct Exposure for a specific Film Speed , the light value will have to converted to an Exposure Value , EV. For a film of ''ISO rating'' 100, the relationship is one to one. For an ISO 200 film, the EV is obtained by adding one to the LV. For ISO 400, add two, etc. For slower film, like ISO 50, subtract one and so on. Further compensation may be desired to compensate for the brightness of the object, and to achieve artistic effects. Some typical values are:
To obtain correct Exposure for a specific Film Speed , the light value will have to converted to an Exposure Value , EV. This is done by converting the Film Speed ISO rating, , to a ''speed value'', : The exposure value is: For ISO 100 film, the relationship is one to one. Further compensation may be desired to compensate for the brightness of the object, and to achieve artistic effects. See also: Exposure Value EXTERNAL LINKS |
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