By Roger (8 January 2015)
I'm a big fan of continuous lighting, as a bright flash can disrupt pretty much any event. In addition, when I'm photographing small children, they can lose all their spontaneity when you fire a flash. That's the last thing I want for my little subjects.
There are times, however, where flash is the best solution. If you're traveling, you may not want to carry all the gear that comes with continuous lighting. At weddings, you need to be able to move around during the ceremony and reception. Even outdoors, you'll sometimes want just a little pop of light to improve your shot.
While flash is often a tool that new photographers shy away from, it really isn't any more complicated than any other part of photography. It just requires practice and experimentation until you have a good grasp on how your flashes work and how to best incorporate them into your workflow. And you have the ability to check your LCD to be confident that your exposure solution is a good one. Here are some examples and hints to help you get there more quickly.
The first thing I always do is remove the flash from the camera. If your camera has a little pop-up flash, you should buy a separate unit; that little flash will give you poor results almost every time. Everyone has seen red eyes in photos. This is caused by a flash, directly in line with your lens, reflecting the retina back into your sensor. Yes, you can fix it in post-processing, but why give yourself extra work?
Get that flash off the camera! A simple sync chord (from $12-25) and an inexpensive flash unit ($70-$150) will be fine. The light from a cheap flash is not less useful than the light from an expensive flash. Your camera brand's dedicated flash unit is ideal, but will cost you more.
My camera has enough ISO sensitivity to shoot the photo, above, without flash. The flash allowed me to bypass any worry about noise and keep the shutter speed high enough (1/125) that there wouldn't be any motion blur. If you look closely, you'll see the background is darker than the subject. Not by much, but enough to guide the viewer's eyes directly to the subject. Light brings things forward; shadows move them back. You can accomplish this by taking an exposure reading on the background, and, then, dialing down your exposure by a stop or two. The flash will fill in the light on your subject. I always begin with my flash power dialed down, so I don't blast a full load of light into the subject. When you've practiced this, you can develop a quick starting point.
Aside from dialing down the flash power, you always want to pay attention to the direction of the light as it hits your subject. Reflections and lens flares can add interest to some portraits, but they shouldn't be there if they distract. A subject with glasses rarely wants to have them used for your artistic reflections. The best way to keep their spectacles free of these distractions is to ensure that the reflection bounces away from your camera lens. I held the flash on camera-left and bounced the flash, angled, on a nearby wall.
At weddings – always check to see if the celebrant allows flash during the ceremony; many don't – I keep the flashes to the minimum. There are times, though, where the flash can help you catch a nice moment.
I hope you have noticed that these photos do not show a highly-lit subject, with the jet black background, you see in many flash shots. Exposing for the background, instead of relying solely on the mighty power of your flash, is the way to make for a more evenly lit photograph.
At the reception, you have to move around the crowd, gathering photos of the couple and happy guests. You may be able to set up a light kit in the corner, and guide people into your set-up. I prefer to make more candid photos, with a flash. I want to catch them while they're partying, not drag them away from the party to some stuffy corner. You're not making art here, you're recording the event. I was lucky to have a white ceiling in this hall. The flash is diffused in a translucent modifier and bounced straight up.
Finally, use your flash outdoors to add a pop of light to highlight your subject. One of the easy tricks photographers will use in bright daylight is to take the subject into open shade. This can lead to some flat and boring lighting. In addition, since your camera's computer will call for more light-gathering, you get hot spots wherever the natural light comes into the photo. Again, if you expose for the background (can you hear me pounding the table on this one?), you won't have that problem. Don't do what everyone else does; instead, break out your flash. Your photos will look much better without those burned out highlights.
All of these photos were taken with one flash, attached to the camera with a sync chord. It's a very inexpensive set-up. It allows me to move with the action, but still ensures enough light to properly expose the scene.
The year is still new enough to slip in an extra photography resolution. Learn to use your flash. Stop letting your batteries die from disuse in your flash – they want to be used to make your photographs better. Practice, practice, practice, until you have as much fun with your flash as the rest of your gear.