Sometimes a photo might need a little more oomph due to strong back-light or perhaps you simply want to brighten deep shadow areas on your subject and you can do this with fill-flash. While there are many fill-flash photography techniques, the two most common are balanced-flash and overpowering the sun with flash.
The whole idea behind fill-flash is to get the correct light for your subject while you maintain proper exposure for your background and sometimes foreground too, so the first step is to ensure that your scene is properly exposed. There is one key rule that will help you with this especially when an outdoor scene is involved, or the outdoors is visible through a window in your indoor photo — the Sunny 16 rule.
The Sunny 16 Rule
Basically, the Sunny 16 rule states, that on a bright sunny day, if you set your shutter speed to the equivalent of your ISO your aperture for a correct exposure is F/16. Here are a few things to consider that can alter the Sunny 16 rule:
- Time of day. Early in the morning, or late in the afternoon, the light is less intense, so set your camera lens aperture appropriately for the reduced ambient or natural light.
- If clouds are present, or on an overcast day, open the aperture up at least one F/stop value, normally F/11, during the brightest part of the day.
- You can photograph your subject with a dark background, such as rocks, foliage, building walls, etc., behind them and this allows you to open up your lens aperture. Your background will be overexposed, but only you will know the background is lighter as it will appear normal to anyone that views your final photo.This is an old photo trick when you can’t get enough power out of your flash unit to match the F/16 aperture value. In other words, you’re not shooting into the brightest part of the scene, or into the sky.
- When working outdoors with snow, beach, or water, increase the aperture value up to one-half or a full F/stop to compensate for the amplified light from these natural reflectors.
- In indoor photography, if you include the outdoors through a window, you must consider energy efficient glass windows will reduce the aperture value too.
So, it’s important to remember with fill-flash photography techniques that during the brightest part of the day, you’ll need a flash output value that strikes your subject at a minimum of F/16 at ISO 100. And this is just to balance your fill with the existing outdoor light.
While most portable studio flash units can achieve this value, especially those with an output of at least 1000 watt-seconds, most camera flash units lack the power when you use long focal length lenses. The same goes if your subject is more than ten feet from your flash. Yes, you can get closer to your subject, though you might have to switch to a wide-angle lens and this could distort your subject’s body.
Balanced fill-flash is just that, a fill of artificial light onto your subject to bring the subject’s exposure value to match that of the background. This helps reduce or eliminate shadows but also adds contrast to the image. Balanced fill-flash is probably the most popular fill-flash photography technique because today’s camera systems can provide this automatically.
Sometimes this “auto” technique works and sometimes your subject is overexposed, while other times the fill-flash is barely seen. The happens because in the automatic mode your camera works off sensors and proprietary software programs based on averages. You’ll get more consistency with fill-flash photography techniques if you shoot in manual mode and consider the Sunny 16 rule.
If you shoot with a portable studio flash system you’ll have to shoot in manual mode regardless, unless your flash system has a TTL remote trigger designed for your camera. If you use your camera’s propriety flash system instead, you can adjust the fill-flash effect through the flash exposure compensation dial or menu on your specific flash model.
So, if your camera’s automation system is fooled by the scene, simply adjust the flash, not camera, compensation by adding (+) 1/3-stop values until you get the correct exposure on your subject or subtract (-) in 1/3-stop increments if your subject appears too bright or washed out. Check your LCD screen and histogram for proper exposure.
It’s usually easy to balance fill-flash with a subject outdoors, especially if you keep the Sunny 16 rule in mind, however there are times, like a sunset, or when indoors, where you can’t achieve this balanced look. No problem, you can capture the ambience of your background and maintain the proper exposure of your subject simply by dragging your shutter.
Drag the Shutter
While in manual mode on your digital camera, you can drag the shutter, or slow your shutter speed down — don’t worry about a tripod, the duration of the flash is the real shutter speed for your subject. When you reduce the shutter speed, you’ve simply made the background brighter. Your subject’s main light source is the flash and your foreground and background, when outdoors, relies on natural sunlight. Though this works only at early sunrise and sunset, not during the brightest hours of the day.
While balanced fill-flash helps brighten up your subject, it also adds contrast and sometimes your photo can take on the appearance of a cliché “flash” picture. I personally am not a fan of balanced fill-flash, in fact, I prefer to add life to my subject through reflected light, like the light that comes off my SUNBOUNCE MINI or PRO with their Sparkling Sun reflector fabric.
In fact, bouncing flash off a reflector fabric or a reflector card when it comes to the SUNBOUCE BOUNCE-WALL, flatters your subject more than direct flash.
Overpower the Sun with Flash
Whether I use reflected flash or direct fill-flash, my preferred fill-flash photography technique is to overpower the sun with flash. In order to overpower the sun with flash, you must have a portable flash system or camera flash that has a substantial power output.
For portable studio flash units, ideally 1000 watt-second power packs with a matching flash head work best during the brightest part of the day. One reason for this higher power output is the light modifier used in front of the flash head will absorb some of that flash energy either through baffles (inside a soft box), diffusion panel (in front of the soft box), reflectors (metal dome reflector on a beauty dish and the pan itself) or in the case with umbrellas when you shoot through or bounce off the umbrella fabric.
Even with a ring flash, a frosted glass is best, and it too will absorb some of the light as the light passes through this diffused glass. Bottom line, don’t pay for a portable studio flash system twice, buy one that has the power, so you won’t regret it later. Also, make sure the advertised watt-second output of the flash system is “true” not “effective” watt-seconds. Lighting systems that state “effective watt-seconds” are nowhere near actual true watt-second units.
The technique to overpower the sun with flash is based on a photographer’s personal taste and style, as some photographers like more dramatic versions of this method, while others just want a tad of the effect. Basically, it’s all about darkening the background for dramatic impact while keeping the subject properly exposed. Though the background is overpowered for eye-popping impact of the subject, not necessarily for background elimination or to create a black background. If you want a pure black background, take it to the studio with a black fabric or seamless paper background.
High Sync Speeds
Because of the Sunny 16 rule to overpower the sun means you need a flash output of at least F/22 at ISO 100 or at least one-stop more powerful than the sun when your ISO is equivalent to your camera shutter speed. The problem here is that some lenses for today’s digital cameras in the 35mm format don’t go past F/16 and when this happens, you hope your camera has a high flash sync-speed beyond.
Most cameras today sync up to 1/200th or 1/250th of a second and that works well for most daylight situations to over power the sun by at least one to one and half F/stops. Though some photographers prefer to overpower the sun with flash by more than one F/stop, so there are a few things that can be done. One is to use a neutral density filter, such as one that gives you a light reduction of one or two full F/stops.
Polarizers and Neutral Density Filters
Neutral density filters reduce the intensity of all wavelengths of light equally, thus no changes in color rendition or hues of the image. The most commonly used neutral density filters are the ND2 for a one F/stop reduction or the ND4 for a two F/stop reduction. You can also use a polarizer for at least a one to two F/stop reduction, as polarizers not only reduce light and reflections, but they can create a more saturated background or sky too.
Ultimately how much you want to over power the sun with flash, whether it’s a half F/stop, or two full F/stop values is a personal choice. Whether you want to balance fill or overpower with flash, the idea is to liven up your subject with light and create or maintain a more dramatic background. Today photographers can see their results instantly and adjust their image exposure with fill-flash photography techniques that meet their photographic style and to add a little oomph into their photos.