Many photographers experience anxiety when they think about using flash. It’s a big unknown, difficult to control and to predict what the results might look like.
Knowing when you need to use flash to improve a photograph is just another choice you need to make. A little like deciding what lens to use to take a particular photo. Obtaining the right amount of light from your flash to compliment your picture is key to effective fill flash photography.
In this article, I share some thoughts on when and why you might choose to add fill flash. I’ll also walk through seven situations where using fill flash helps enhance a picture.
Using fill flash – what, when and why
Fill flash is typically used to balance with the ambient light to provide the main subject with a more pleasing exposure. So you are filling in some additional light to obtain a better or more interesting exposure. Balance is key. When light from a flash overpowers the ambient light, this is not fill flash.
You can make use of fill flash not only at night or in dark locations, but also when there is plenty of light. Fill flash can be used to effectively decrease or eliminate unwanted shadows when the ambient light is very bright.
1. Fill flash and bright sun
The bright sun casts a hard-edged, dark shadow. When there’s no other light source or reflected light, contrast can cause problems.
Photographing people in bright sunshine they will often have dark shadows under their eyes, nose, and chin. Adding some fill can help to fill in these shadows.
Adding just the right amount of light from your flash is important so it’s balanced with the sunlight. In this photo of a mannequin I saw on the roadside one morning, I have added fill flash. I directed my flash at the smiling figure. I set the output so she was well lit, but her shadow, from the sunlight, is still clear.
2. Electric light source and fill flash
When you have any light source which causes your main subject to be poorly lit, adding fill flash can help.
The large magnifying glass in this photo has a light behind it to illuminate the electronic board. Had I not added any fill flash, the electronic board would be well exposed, but the white surround of the magnifying glass would be underexposed.
Fill flash can even out the light when it’s important to have everything in your photo well exposed.
3. Using ambient light as backlight
Photographing your subject with the main light source behind it is known as backlighting. This situation again can create problems when you want evenly exposed photos.
Adding fill flash to a subject which is backlit, you can bring a balance of light and obtain an even exposure.
In this photo of the young woman drinking, I wanted to include the train in the background. The light behind her was quite strong so I balanced it by adding in a burst of flash from my right.
By controlling the flash power to output slightly less light from the ambient light, I was able to leave a soft shadow on her face. Had I not included the flash, the shadow would be too dark and not help convey that it was a hot day so well.
4. Fill flash with a bright background
Bright backgrounds, even on cloudy days, can sometimes cause you to underexpose your subject if you’re not careful. Adding some flash helps.
The bright background behind my model in this photo was not super bright, as it was an overcast day. I wanted her to be a little brighter than the background, so I placed the flash to my left. I also had a small softbox for the flash so it was diffused to match the feeling of the ambient light.
5. Light your subject at sunset or sunrise
At either end of a day, when the sun is low in the sky or just below the horizon, fill flash can be helpful. Sunrise and sunset can produce beautifully colored skies, but they are often going to be brighter than your subject.
If you set your exposure for the sky, your subject will be underexposed. If you set your exposure for your subject, your sky overexposes and you lose the effect of the color in your photo.
Adding a little flash to your subject, so it’s balanced with the light in the sky, will light your subject and allow the color in the sky to be captured also.
6. Fill flash and fire
This example is a little different but has the same principle. In this case, part of the main subject is the light source.
I photographed this inside. The workshop was fairly dark so the flames were throwing shadows over the dark metal.
Had I not included any flash in this scene, the crucible, tongs, and surrounds would have been too dark. I wanted more detail to be visible in these areas.
7. Slow shutter and fill flash
Any time you have movement in a scene you can use a slow shutter speed to create motion blur in your photos. Using some fill flash can add a whole other dynamic, particularly if you set camera and flash to synchronize well.
Many cameras allow you to set the synchronization to fire the flash just before the second, or rear curtain of the shutter closes. This causes a partial ‘freezing’ of the motion in a more attractive manner.
Again, balancing your flash output is important to achieve the best effect. For this technique, I generally set my flash output to be slightly brighter than the ambient light. If the output is the same or less you will not see the effect much or at all.
How to use your flash well
You do not need to have your flash mounted on your camera’s hot shoe pointing directly at your subject.
Diffusing your flash, or bouncing it off a reflector or other surface, will soften the light. Placing your flash off to one side, above or below, will often produce more interesting, pleasing results.
Controlling the output of your flash is always vital. Too much or too little light from your flash causes an imbalance. You need to decide how much light your photo requires and make the correct adjustments to your flash.
Through the lens (TTL) metering is often the easiest setting. You can also use the Auto mode. Sometimes, with either of these settings, you may need to dial in compensation so the light will be a little stronger or weaker.
Using the Manual setting on your flash requires a little more thought and experimentation. It can often produce a more reliable output from the flash when you are taking a series of photos. This is particularly useful when there are variables in light or camera/subject/background distances.
Adding fill flash can make a positive difference to your photos in many situations. When you are not content with the ambient light alone, consider adding a little light from your flash. Even if the only flash you have is the pop up one on your camera.
You may not get the right result the first few times you try this method. Practice. Study your results. Compare photos where you did not use the flash with ones where you did. In time, you will develop a sense for when adding some fill flash will enhance your photographs.
Share some photos in the comments section below and tell us of your experience with using fill flash, whether you were successful or not.