Saturday, June 13, 2009

What is Exposure?

When we talk about exposure, we are talking about how much light reaches the sensor in your camera (or how much light the sensor is "exposed" to.) Too much light is bad (over-exposed); too little light is bad (under-exposed.) When it comes to exposure your camera does all the work if you let it. Usually it will do a great job, but it is important to recognize when you need to give it a little help. Check out these examples so you can learn how to look for visual cues which indicate incorrect exposure.
All three of these pictures were taken in less than ideal conditions--in other words, normal conditions for moms. The scene is lit by a florescent light from one side, an incandescent light from another, and a flash on the camera.
This first image is not terribly dark (most people will notice that without instruction) but it could be better. When evaluating exposure, look at the whites in your image. Here, the white shirt is dull and grey. Notice also that the colors are muted compared to the properly exposed image.
This image, too, is not terrible, but notice why it isn't quite right. The patches of white on the sleeve have lost detail. Looking closely at these patches, you wouldn't be able to see any texture on the shirt. Another place to look is the brightest part of the face--in this case the nose. Notice the unnatural color making the nose look almost neon.
Correct Exposure
Tomorrow we'll talk about how to adjust your exposure when you notice it's wrong.