Quote Originally Posted by darkrainfall
Can anyone explain the significance of 18% gray? Where did it come from and why is it the standard in metering for photography? I've read about how to read for 18% gray, but I can't make it work, if I don't understand it... *smile*
This is a mid tone gray. It's halfway between white and black. I don't know where the 18% comes from.

The basic idea is that the average scene adds up to an overall midtone. The key is knowing when it doesn't and how to compensate. Or, using it to insure the part of the scene you want to be a midtone is.

The color doesn't have to be gray, it just need to be a midtone color. Green grass for example, works well.

Mike