How to Use Existing Light when Taking Digital Photos
If you don’t have access to lighting equipment for your digital photos, you can adjust the existing light (called ambient light by photographers) to create the effect you want. Work with the existing light — light that you find at a location (as opposed to studio lights):
Modulate (modify) existing light with reflectors.
You can use a piece of white cardboard as a reflector if the light is too harsh, as illustrated in this figure. Foam board also works and is stiffer and easier to position than cardboard. A piece of crinkled aluminum foil can make a brighter, more contrasty reflector. Mylar space blankets also make a lightweight, portable metallic reflector.
Place a shiny subject in a white tent.
You end up with beautiful soft lighting and no reflections of the surrounding room on the shiny subject matter.
Block the existing light.
Put black cloth or cardboard outside the subject area, like in this figure. The black material absorbs light and darkens shadows for a dramatic effect.