Metering is a big mystery to most newbies. I think it is because there are 3 factors to consider:
- Location of the camera
- Direction of light
- Direction your subject is facing
Take a moment to observe this photo: The model is closer to the camera and facing away from the light. Because the meter was used to determine the proper exposure for the curtains and the model is in shadow, you will not be able to see the face or the details of her outfit.
If the meter reading was taken of the model facing away from the light source, you will be able to see the detail of the woman but the curtain would be overexposed.
So as a photographer you must decide if you want to meter for the model or the curtains. In this scenario the third choice is for the model to stand still and take one photo metering the curtains then another metering the model. You can then take both photos and use photoshop to combine them (not easy).
Take a moment to observe this photo: The other option is to have the model face the curtains or window, and move the camera so that the back of the camera is closest to the window. This way the camera and photographer should be facing the same direction the light is coming through the window. Now when you meter for the model avoid the direct sunlight area hitting her. This will result in the photo above where you can see the detail in the clothes. This is kind of a compromise.
Remember, if you meter in the area where the direct sunlight is hitting the model you will have the same effect as the second photo where you metered for the sunlight and the model will be darker.
Remember to observe your camera's location, the direction of light, and the direction your subject is facing. Practice noticing things like this will help improve your photography.
Photos by lyingwiththewolf and hillaryraindeer