
thing is that it's highly adjustable. Get really close to the window and the light is big and soft and can surround your subject in great portrait light. Move away from it and it gets smaller and more focused; this can be really dramatic but watch that you have enough light to avoid a blurry photo due to low shutter speed. The third great thing about window light is it's directionality. Very often what makes a portrait interesting (or not) is the difference between the light and shadow areas on the subject. When lighting a person with a window, you will automatically have light coming in from one direction and you can control

how it falls on your subject just by turning them towards or away from it. Most of the time you would put your subject at the window and have them face you with the light coming in from the side. But, if it was a sliding glass door, you could also open it up and photograph from outside giving you a more direct/frontal light (But it's cold out there, so maybe save that trick for a very hot summer day when you need to be in the shade). Practice by simply having someone stand at a window for you and move them around. Look at how the light changes on their face as you turn them and move them closer or further away. It's a great way to experiment with how the size and direction of a light source can effect the mood of a photograph. Play around with it. Experiment and have fun. And the next time your camera wants to automatically blast your subject with that ugly on-camera flash that you know you hate, turn it off and find a window!

ps: These three photos were lit only with window light. In the first, the baby's face was about a foot away from a very large, floor to ceiling window facing North. The second photo was taken in the middle of a large, vaulted living room with large windows floor to ceiling. She was facing the windows and I had my back to them facing her. The last one (of my daughter Mina) was right next to another large, North-facing window which is just out of the frame to the right.