Equivalent Exposures

Equivalent Exposures are settings that let the same amount of light into the camera. If you set your camera to a particular setting, knowing the equivalent exposure to get a smaller depth of field (based on aperture), larger depth of field (based on aperture), or setting to stop the action (based on shutter speed) is important to altering the artistic look of the photo.

Above is a chart that is helpful in calculating the equivalent exposure of a setting.

Keep in mind that exposures are written as aperture@shutterspeed (i.e. f5.6@250 or f8@125)

Go to the following websites for a tutorial on equivalent exposures:

http://www.dslreports.com/faq/11775 - good site to start with

http://digital-photography-school.com/moving-toward-manual-settings-understanding-basic-daylight-exposure-and-equivelant-exposure - excellent site! This photographer knows how to make equivalent exposures easy - there are a lot of ads, so just move past them as you read. Ignore the links on the page to Part I, Part II, and Part III.

http://photographic.com/issue-1-exposure/1208_103EQUIV - this site pulls it all together with examples to demonstrate the importance of equivalent exposures and how we will use the concept.