This is part four in a series of posts about learning off-camera flash. Find the previous posts here:
- Learning Off-Camera Flash: Part One
- Learning Off-Camera Flash: Part Two – Studio Strobes
- Learning Off-Camera Flash: Part Three – Studio Headshots
Quality of Light
As you experiment with light placement, you’ll start to be able to anticipate the results certain light setups will produce. Professional photographers learn and practice their camera’s settings and features until it becomes second nature. They do the same with off-camera flash.
We do it for one main reason: As you develop these skills it will give you a tremendous amount of creative power. You are no longer just pressing a button and hoping to get a good shot. With enough practice and skill development you are able to construct the vision you have in your head. Your camera and lights are just tools you use to craft the final image.
Lighting has a profound influence on the mood and feeling of a scene. Photographers often refer to the “quality” of light. Indeed, light has many qualities that influence how a viewer of a scene interprets that scene. Different qualities of light can help the observer feel certain emotions, or “read” a photograph in a certain way.
Let’s look at the various attributes of light:
Direction – The direction from which light strikes a subject has a dramatic effect on how our eye sees the subject or how the camera captures the image. Subjects lit from the front tend to apear flat and less defined. Front lighting tends to fill in all shadows. Subjects lit from the side, top, or bottom benefit from shadows that help define shapes and give our eye a sense of dimension.
It’s for this reason that professional photographers like to get the flash off of the camera. If you are always shooting your subject with the flash mounted to the top of your camera, you will always be providing a front light that fills in all of those interesting and defining shadows.
Take a look at the lighting setup that I used when I photographed the Harley in the photograph at the top of this post. I setup two softboxes above the bike that provides a directional, yet soft light from above. The direction of this light provides defining highlights, shadows, and reflections that you wouldn’t get if you lit the bike from the front. Light also bounces off of the white backdrop and adds a little fill light that helps show details in the shadow parts of the image.
Sometimes light as no apparent direction. This type of light is sometimes referred to as ambient light. This type of light is extremely soft with very little or no shadows created. Ambient light seems to come from everywhere. This can often be observed on an overcast day like in the image below.
In the context of off-camera flash, photographers call existing light, or light not created by a strobe or flash ambient light. A photographer may choose to balance his flashes with this ambient light and use it to help light the scene, or he can overpower the ambient light completely. If you want to include ambient light in your photo, it’s best to set your camera setting to expose for the ambient light first, and then add flash and adjust power to compliment the ambient light.
In the photo below, I set my shutter speed and aperture to expose the sunset and sky how I wanted it to appear. These settings made it so the foreground object, the sand rail, was too dark. I then added a pop of light from a speedlight triggered with a pair of Pocket Wizards to illuminate the vehicle.
With off-camera flash, you can learn to control the exposure of the ambient light independently of your speedlight or strobe. This gives you the ability to expose a scene in a way that would be impossible without the use of flash.
Color – Without getting too technical, light itself can appear to be a certain color depending on the source or if it has passed through a colored gel or filter. You may have noticed the yellowish color that street lights often cast. Studio lights and speedlight flashes are usually designed to match daylight or 5200K color temperature.
Mixing light of different colors in a single photograph can lead to interesting results. Notice in the following photograph how many different colors of light there are. The sky is providing a deep blue tone, the streetlights cast a yellow color, and the building has lights that appear green.
When using off-camera flash, it can sometimes be desirable to try and match the color of the light from your flash with the existing light in the scene. You can do this with a set of color modifying gels or filters. The ability to change the color of light from your flash will give you even more creative control of your photography.
Softness/Hardness – The relative size of a light source in relation to a subject is the determining factor in how hard or soft the transition between highlights and shadows on the subject will be. Generally, softer light is more flattering for photographing portraits.
The sun is a huge light source right? Shouldn’t shooting in direct sunlight provide great light?
No. This is a common mistake amateur photographers make. The sun is huge, but it is a relatively small light source in relation to us here on Earth. From our relative position, the sun is no more than a small, bright sphere, almost a point of light. The shadows direct sunlight creates are extremely harsh with razor sharp edges. Many amateur photographers don’t realize this. They choose to shoot in the direct sunlight instead of the shade. Not only do the people in these photographs have squinty eyes, but the image end up looking amateur.
Notice the quality of light in the two images below. The photograph taken in the shadow of the trees is much more appealing. The shadow blocks the direct light from the sun and allows the ambient light to illuminate the subjects creating beautifully soft shadows and tones.
So what does this mean for flash photography? A flash strobe head or speedlight is a relatively small light source. Professional photographers increase the relative size of these light sources with light modifiers, such as softboxes. The only reason light from a softbox provides softer light on a subject than a bare flash is because the relative size of the light source is made bigger with the softbox. If you were to move the softbox far away from the subject, the light would become just as hard as a bare flash or even the sun!
As you move the softbox away from the subject, the relative size of the lightsource becomes smaller.
Brightness – This one is pretty straight forward. Brightness of a light source is again a relative thing. We control brightness by changing our camera’s ISO, shutter speed, and aperture, but we can also control the brightness of our flashes by adjusting the flash power on the flash unit. By adjusting your camera settings along with your flash power you can balance the ambient light in a scene with any flash you add to supplement the existing light.
Duration – I like to list duration as an attribute of light when discussing off-camera flash. When a flash fires, the actual duration that the light is on is very fast. So fast in fact, that a flash will typically freeze any movement that the subject is making, even if the shutter speed of your camera is slow enough to allow for motion blur. The flash duration effectively becomes a kind of second shutter speed. Because of this, it’s possible to use much slower shutter speeds than you normally would. The flash will freeze the motion.
We will dive deeper into how camera setting effect off-camera flash and ambient light exposure in the next part of this series. Be sure to subscribe so you don’t miss the next part!