The Light Meter
or light meters have a common problem. They can't tell the difference between black and white. In other words, they cannot distinguish toes. The meters are calibrated to see the entire world is medium tone. Great. What that means is they will accurately expose a medium tone subject, such as a green leaf. But what about a swamp? In bright light, the white feathers of a swan two stops lighter the medium, but because the camera has been calibrated to see the entire world is medium grey. Unless you make a change, this one will come out gray in your photograph. Now to get from white to medium grey, the cameras taking away two stops of light where it's under exposing by two stops to get back again from medium great white or you have to do is tell the camera not to take that light away. And you do that using exposure compensation. White is two stops lighter than medium grey, so if I set plus two exposure compensation, my swan will come out looking white. The opposite applies to subject a dark...
er than medium tongue for dark tone subject. The camera's going to try and add light to make them lighter, so I have to do the opposite. I tell the camera, not add that light and gained with exposure compensation. I'd put minus one for dark grey or minus two for black. Let's try and make sure that this black swan comes out looking black. I would set minus two exposure compensation, so the light meter will give you a meter reading for a medium tone subject. It will under expose light tones and over exposed dark tones, all you have to do is ask yourself The question is the subject I'm photographing medium tone. Was it lighter or darker than medium tongue? If his medium tone, you can use the cameras meter reading, but it is lighter or darker than you have to make an adjustment using the exposure compensation. Of course, all this assumes you know how to read tonality. That is a skill in itself.