You’ve seen it on some web sites where instead of giving the shutter speed and aperture used to take a picture, the exposure value (EV) is given instead. A shutter speed/aperture combination is an exposure value and many cameras now have Program Shift which allows you to shift the shutter speed/aperture in tandem to maintain the same exposure value. But for those who like to use their camera in Manual mode, Rod Lawton, of Photo-facts.com, has made available a free download of his handy Exposure Value Guide.
[ Download the Exposure Value Guide (pdf) at: Photo-facts.com ] [ via DPhotographer ]