Photographer's dirty secret: flash is your friend

Sometimes just a tiny fleck of flash can make the subject pop without a harsh shadow, especially if there's nothing immediately behind them. / Courtesy of Michael Hurt

By Michael Hurt

I've met so many "natural light photographers" who are convinced that "flash is so harsh and unnatural." I've heard many a photographer ― especially after Seoul Fashion Week has swelled the ranks of street fashion photographers shooting outdoors ― say things like "I only like to shoot in natural light. It looks so much better." This is just about as wrong as "I prefer the look of film because it has a warmer, more engaging feel."

This misunderstanding of flash is understandable, since although flash is technically easy to learn, it is hard to feel in control of as a photographer.

Flash brightness is easily and subtly controllable by three easily adjustable things:

Aperture: The aperture ring (measured by the f-stop) affects half of an exposure (in conjunction with shutter speed), depth-of-field and flash brightness. Open up to f5.6 and the flash appears bright. Close it down to f22 and it might not show up at all. This is independent of shutter speed and a neat trick for tightly controlling exposures.

Distance: The closer you get, the stronger the light gets. But people tend to think linearly, as in: if you double the distance by backing up, you must have to double the power. No, you have to square it. Flash power falls off exponentially fast with distance. This is why when you back up to get everyone in for that post-family dinner shot, the pic tends to be dark. When you back up to triple the distance while ushering everyone into frame, your little point-and-shoot flash or cellphone light becomes woefully underpowered to put out an exponentially stronger burst than what would've been fine for a shot with a friend who's barely a meter away. That's also why it's easy to control flash brightness with your feet. The brightness is sensitive. You take one step in closer, everyone's bright; one step back, it dims down to take the bright edge off.

Power: Basically, one can turn the light power of a flash up and down easily, like a variable-power lamp. So, a 1/1 (full) power blast is clearly stronger than a 1/2 (half) power blast, is stronger than a 1/4 (quarter) power one, is stronger than a 1/64 power flicker of light and so forth. So when you back up for the family dinner shot, you'd better compensate by turning the power way up, or if you're at f8, opening up the aperture by going to f4. You'll lose depth-of field/range of being in focus, but photographic mechanics always involve a tradeoff.

Photos of Bada (@d.a.d.bada) by Vivienne Chung / Courtesy of Bada and Vivienne Chung

Add a touch of light to a fairly well-exposed ambient light scene, and it usually makes it hit with a bit more punch. And if you're talking about a human subject who is usually standing closer to the camera (and you) than any background (even a wall that's fairly close by), it will usually cast a dramatic shadow that can become a part of the picture's aesthetic. It's quite simple, really.

Also, another little trick that flash can help you pull is evening out heavy contrast in a picture that has a subject in harsh direct sunlight, which creates distracting, nasty shadows. The key principle to understand here is that brightness caused by the sun and flash is not cumulative when they overlap, but rather the brighter part defines the upper threshold and the other part of the light can increase the brightness up until that threshold. So brightnesses can overlap and one basically fills in the shadow until it reaches the brightness point of the other source. So for example, if you have a very bright sunlight subject with harsh and deep shadows, you can turn the flash up until the point where it starts filling the shadows, but that light will not increase the brightness of the sunlight part until the flash becomes brighter than the sun and takes over as the brighter source. So flash can transparently simply fill in the shadows and bring up the brightness of those parts only. This is why one uses the flash as a "fill light" even when it's bright and sunny outside.

Fill flash can be used to bring up brightness in shadows, and is a technique not just for lighting people standing against bright windows. Model: @j.miiiiin_0821 / Courtesy of Michael Hurt

These are just some of the many tips I'll offer to those of you interested in improving your photography as not only a columnist here, but as someone who has run the longest-active, private photography class in Korea that is conducted in English. I plan to touch on points such as depth-of-field, the effects of different shutter speeds, compositional choices and more, to introduce some noteworthy photographic points, tips and tricks that can improve your photography, whether done on your smartphone, point-and-shoot digital camera or high-end DSLR.

Dr. Michael Hurt is an experienced American instructor who has worked in Korean photography for 19 years. He presently teaches "Contemporary Cultural Theory" and "Trends in the History of Art" at the Korea National University of Arts. His next photography class series starts on Dec. 4. Visit fb.com/photoseoul for more information or to register, or go to medium.com/@metropolitician to see more of his work.