Guide number
id:
guide-number-203-11616094
title:
Guide number
text:
When setting photoflash exposures, the guide number (GN) of photoflash devices is a measure photographers can use to calculate either the required f‑stop for any given flash-to-subject distance, or the required distance for any given f‑stop. To solve for either of these two variables, one merely divides a device's guide number by the other. Though guide numbers are influenced by a variety of variables, their values are presented as the product of only two factors as follows:
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- Guide num
brand slug:
wiki
category slug:
encyclopedia
description:
original url:
https://en.wikipedia.org/wiki/Guide_number
date created:
2005-04-13T20:51:44Z
date modified:
2024-09-09T17:36:43Z
main entity:
{"identifier":"Q260103","url":"https://www.wikidata.org/entity/Q260103"}
image:
{"content_url":"https://upload.wikimedia.org/wikipedia/commons/c/c5/Vivitar_285_guide_numbers.jpg","width":2560,"height":2405}
fields total:
13
integrity:
15