Square Lighting with Natural Light
All you need to create square lighting with natural light is a decent light source, such as a large window and plenty of daylight, as well as a reflector with a hole cut through the center that is large enough to allow for shooting through the reflector. You can cut a hole out of a standard 5-in-1 reflector or purchase a specialized reflector, such as the Westcott Omega 360 15-in-1 reflector, which features a replaceable cutout section. Place the subject with her back to the light source, directly between the light source and the camera. Then, place the reflector in front of the camera with the reflective surface facing the subject, and shoot through the reflector. Expose to the brighter side, but retain some highlight details and push for maximum dynamic range.