How to Use a Flash
Equipped with our trusted smartphone or consumer camera, it has become so easy just to press a button, not needing to think about aperture, shutter speed, and lighting. If the scene is too dark, well, then the built-in flash will pop-up - in the case of a camera - and fire. It seems the smartphone or camera always knows what to do.
However, when you look at these photos on your computer, they often tend to be a little bit harsh, nothing like professionally taken images. Why would that be?
The reason is simple. The light from the flash hits the subject in full force since it is not diffused or soft and does not blend into the surroundings. To make matters worse, with a reflective surface, as is the case with cars, ceramics, or windows, the light comes back straight to us, leaving an unpleasant glare spot in the picture.
It took me years to understand the full meaning of soft light, but once I grasped it, it changed my photography forever.
When professional photographers take pictures, they generally aim for an evenly lit scene with no deep dark shadows or overly bright areas. In nature, these lighting conditions only occur in the early morning hours at sunrise or late at sunset. For this reason, most professional photographers avoid the daytime hours when the sun is bright and the light is harsh.
There is one exception to this rule, though: a cloudy day. I do not mean a few clouds; I mean a sky completely covered with clouds. Why? Because when the powerful sun rays hit the dense cloud cover, the clouds disperse the light and make it nice and soft. You won't notice harsh shadows or bright highlights. The scene is beautifully and evenly lit. See for yourself the next time clouds cover the sky.
How does this apply to a camera flash?
A flash is similar to the sun. It creates a powerful beam of light that is directed at your subject, casting some less desirable shadows and glare spots. However, when diffusing this light as the clouds do in nature, we soften the light and considerably reduce these shadows and glare spots. That's how professional photographers do it. For example, when they shoot fashion, they use giant diffusers to disperse the light and make it look softer and more flattering on the model.
Carrying a diffuser may be a little impractical if you use a consumer camera and pointless in the case of a smartphone because the diffuser would cover your phone's lens. However, if you are taking pictures with a standalone camera, these simple techniques can noticeably improve your photos:
Mount your camera on a tripod. Your camera will often trigger the built-in flash when it senses that the light is insufficient at your current aperture, shutter speed, and ISO settings, especially when taking handheld shots. The solution is simple. If you are taking pictures of flowers, architecture, or other stationary objects, place your camera on a tripod and reduce your shutter speed. A longer exposure time lets more light into your camera, thus avoiding using a flash altogether.
Reduce the flash output. Sometimes by increasing your camera's ISO, reducing the aperture value, and slightly lowering the shutter speed, you can let so much more light into your camera that you can reduce the flash output significantly. A less powerful flash makes the shadows softer.
Adjust your flash output to your surroundings. When a camera calculates the flash output, it may get confused, resulting in an overpowering flash. When this happens, your subject may be overly bright, and your background too dark. In this case, manually reduce the flash output and retake the photo.
Turn on rear curtain sync. If you shoot in a dark room and want to capture the ambient light while freezing your subject's motion, turn on "rear curtain sync" on your camera and set your shutter speed to 1 second, for example. The shutter will then open, capture the ambient light, and right before the shutter closes again, the flash fires.
Place a sheet of white paper in front of your flash. If you cannot avoid using a flash, hold a plain white sheet of paper in front of the flash when you press the release button. Leave a 1-inch gap between the paper and the flash. A piece of thin white fabric will also do the trick. You will notice how much softer the light is on your subject.
Get closer to your subject. The greater the distance between you and your subject, the longer the light has to travel. Since its intensity decreases exponentially the further you are away from your subject, you will need a stronger light source to compensate for this fall-off. An object twice as far away from you only receives a quarter of the light (inverse square law). However, the opposite is also correct. When you half the distance to your subject, you can reduce the flash output by three quarters. And a less powerful flash casts softer shadows. Therefore, many high-end photographers use a wide-angle lens and leave only a foot or two between their model's face and their camera.
Bounce your light off the ceiling. If you use a separate flash unit instead of the built-in one, turn its head straight up and point it at the ceiling. Since most ceilings are painted white, it will diffuse the light and make the shadows on your subject softer.
Bounce your light off a white foam board. When you bounce light off the ceiling, it often leaves slight shadows under your subject's eyes and chin. To reduce these shadows, hold a white foam board below the subject's face. The foam board reflects the light coming from the ceiling back towards the model, and those dark areas will disappear. This technique may require a second person, but the results are well worth the extra effort.
Using a flash can be a lot of fun. You can create stunning effects and beautiful, evenly lit images. However, for that to happen, you need to take control of your camera and familiarize yourself with its essential knobs, dials, and buttons. At first, the challenge may seem daunting. However, your friends and family may soon notice an improvement in your images and encourage you to stay on your path and keep learning.
Perhaps, who knows, you may accidentally discover your passion for photography as I did many years ago when I tried to figure out how to use a flash.
