You’ll please excuse me while I have a love affair with window light. Of all the things I have learned over the past six months, it is this: turn off the lights in the room and let the windows work their magic.
In photography, when we talk about light, there are at two major things to consider: quantity of light, i.e. how much of the stuff there is, and whether there is enough to get a good image, and quality of light, i.e. how hard or soft it is, and whether it is directional or not. Windows give a wonderfully soft, directional light that can be used to create a number of lighting effects. There might be a tendency to think that the more light the better, but this is not at all true; great lighting creates some type of effect by negotiating differences in light and shadow.
As a general rule, diffused sunlight is beautiful, and there’s lots of it. Artificial lighting, whether incandescent, fluorescent, or something else, looks odd-colored, especially when mixing with sunlight. Best just to leave it to the sunlight, even if the room looks a bit dark. Trust me. It’s probably perfect.
Sometimes a warm light with heavy shadows creates a rich, opulent feel. Shift the camera or the subject just a bit, and the same source can create an open, airy high-key look. This is possible when the room is not flooded with even, artificial lighting, and the photographer leaves the flash in the bag.