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I see so many photographers with such polarizing views about using flash. Sometimes I hear a photographer say “I prefer natural light.” And then some others say “Anyone who says they prefer natural light simply doesn’t know how to use flash.”
I like to think that the real best answers for how to use a flash or not lies somewhere in the middle. I’ll share some tips for using a flash gun that may help with flash photography for beginners and help us find balance about use or non use of flash.
Most of these tips for using a flash gun will be directed to creating portraits, but the principles can apply to other subjects such as small products, still life images, interior spaces and so on.
When to Use and Not Use Flash
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Flash photography basics and tips for using a flash gun begin with knowing when to use one and when to not use a flash. This is especially an important consideration when photographing people.
One of the tips for using a flash gun or not for portraits is to discern what the light is doing for the subject’s face. Under the nose, under the chin, and in the eyes. If the natural light is strong and directional, it will cause shadows that can cause an unnatural appearance.
Another concern is light that is so nondirectional that there is little or no modeling effect at all in the subject’s face. For some subjects in certain situations, this may be preferred. In fact, you could use a ring light flash to create this look if desired. Other times, this may make the subject look flat and uninteresting.
The same principles of when and how to use a flash apply with non portrait subject matter. Interior rooms and architectural features can be especially problematic for lighting, so I often recommend as tips for using a flash gun or not to just go ahead and skip the flash and try something else such as bracket and merge HDR.
Fill Flash Portraits Look So Natural
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I know what you’re thinking right now, “Have they seen these flash portraits?!” Sure, I’ve seen those. Usually the problem is that the flash has overpowered the scene and the subject. So it looks like a paparazzi pic.
What you want is a balance between the ambient light and the flash exposure so that the image doesn’t have that stark appearance. Balancing flash exposure with ambient light is called fill flash and is one of the flash photography basics for portraits.
One of the reasons why some photographers may shy away from fill flash for portraits is because it can be somewhat intimidating to calculate since it involves so many factors. Flash power, ambient light, lens aperture, ISO, shutter speed, and focusing distance are all involved. Get just one of those figures wrong and the fill flash won’t look natural.
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Modern flash photography benefits from two amazing leaps of photographic technology, TTL flash metering and autofocus. While these are commonplace in virtually all digital cameras now, from entry level to professional, their invention and implementation in photography facilitated what was virtually a revolution in flash photography.
Through the lens (TTL) flash metering reads the light actually coming into the camera and impacting on the digital sensor or celluloid film. We’ll stick with digital since that’s most likely what we’re all using.
The meter reading is based on the ISO, the power of the flash, and the lens aperture. This is where technology gets cool. Since it’s the light coming in through the lens, it’s already affected by the lens aperture. The shutter speed and ambient light levels factor in as well.
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The final piece of the puzzle is the subject distance. Autofocus control provides the needed information. The AF sensor tells the camera brain what that distance is and then all that information is mixed together to create a balanced fill flash exposure.
The technology is so good that all levels of photographers from beginners to advanced serious amateurs and even many professionals use it when they need a balanced and natural appearing fill flash exposure. This automation is so good that the resulting portraits often appear to the untrained eye that no flash was used at all.
In order to access this “smart” mode for flash, scroll through your camera menu in the section for flash. Each brand has a slightly different name for this mode, so check your instruction manual for the specifics of your particular camera.
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Watch Those Angles for Bounce
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To avoid harsh shadows and also to avoid “red eye” in flash portraits, many flash units have a functionality of tilting and sometimes swiveling the flash in order to take advantage of a ceiling or a wall to bounce the flash off of, making that surface into a type of diffuser.
An important set of tips for using a flash gun in this way is to make sure that there is actually a reflecting surface and to watch those angles.
The first thing sometimes apparently causes confusion for some flash users. I can’t tell you how many times I see a photographer trying to use bounce flash outside or in a very high ceiling indoor arena. The flash needs something to bounce off of for this technique to work, so unless you have a light dome or reflector card, pointing the flash up at angle when there's nothing there to reflect it is virtually useless.
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The second item of important tips of using a flash gun for bounce flash is that the angle of reflectance is equal to the angle of incidence. In other words, the light will reflect off the surface (wall or ceiling) at the same angle it hits.
So you will need to check your distance to the subject and how high the ceiling is to give bounce flash a chance to work. It’s usually good enough to estimate the angles since the power of the flash can be adequately controlled by the TTL flash metering we discussed earlier.
Other Tips for Using a Flash Gun
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Some other helpful tips for using a flash gun include using accessories such as a light dome, reflector card, diffuser, soft box, or portable umbrella. TTL flash is a good mode for macro photography, and some cameras and flashes allow for the flash to be used off the camera and as part of a multiple flash configuration.
For this short list of tips for using a flash gun, you’ll notice we assumed using an external flash unit instead of the small built-in pop-up flash found on many current digital cameras. The TTL and fill flash modes can be used with these tiny flashes, but they are limited in power and can’t be used for any bounce flash techniques.
Check out what is available for your camera, including 3rd party manufacturers. Using flash or not is a decision to be made based on the needs of your photography, so try it out, you might see that flash is a great tool but it definitely doesn’t always need to be used.
And when we do use it, we can be in control as long as we know what these flash guns can and can’t do for us.