In case you don’t know, a black flag is used in photography to absorb light and keep it from reaching your subject. It is the opposite of a reflector which bounces light onto your subject.
Interior photography is not unlike other types of photography in which you have a main subject, must compose carefully and place lights in the correct location. But it can present challenges too. Take a look at his picture:
See that window? Sunlight is streaming in and bouncing off the floor which then reflects up into the bathroom. It’s typically bad practice to light a portrait of a person from underneath. It gives them that scary camp-fire-ghost-story look. Well, the same applies here. Look carefully at the shadows and you can tell the light source is coming from underneath. Even with flash, I could not make it looked balanced or pleasing. Here’s another look:
You can see the sun bouncing off the floor and wall. I did not want to leave it as is and have people think that I lit the bathroom from underneath. I was stumped until I remembered that I always bring my 5-in-1 reflector with me. One of the sides is black. So I draped that over the spot where the sun was hitting:
Notice the shadows cast by the bathtub faucet and light fixtures are less noticeable. The glare on the cabinet is reduced as is the brightness of the tile on the bathtub.
Most people may not think of using a 5-in-1 reflector for interior and real estate photography, but it’s just another photographic tool which helps to control the light.