Photographic term Reciprocity law SWPPOne Vision Imaging Ltd

SWPP Home
Magazine
About us
Join

Term - Reciprocity law


Reciprocity lawSWPP Photographic Glossary

Saturday 23rd June 2018  




SWPP

Glossary
 

Read all about it...
Stop Press...
Members in the News!

The Societies' Photographer
of the Year 2017
Results Announced!

Image Competition
Free entry for SWPP members.

Membership
Free Information Pack

Qualifications - An Overview

Reciprocity law

To make an exposure, a photographer can, for example, choose a combination of a small aperture and a slow shutter speed or a large aperture and a fast shutter speed. Each movement of the aperture is classed as one stop go from f/8 to f/11 and you close the aperture by one stop. Similarly by adjusting the shutter speed from 1/125sec to 1/500sec you reduce the exposure by one stop. If you adjust the aperture by a stop and counteract this by also adjusting the shutter speed by one stop you will produce the same exposure value. Therefore an exposure of f/8 at 1/60th could be changed to any of the following combinations: f/11 at 1/30th, f/16 at 1/15th, f/5.6 at 1/125th or f/4 at 1/250th. This is called the law of reciprocity (if one value increases the other will decrease proportionally and visa versa).



 

Information provided by: SWPP
More Photographic Terms

SWPP, 6 Bath St, Rhyl, LL18 3EB
Tel  01745 356935
International code (44)
Copyright 2006-16 SWPP. All rights reserved.
10/02/2017 10:29:05