Off Camera Flash Photography Tips – Quality of Light

As we continue learning more about off-camera lighting, we need to examine the beam of light coming from the light source. How big is it? How close it is? Which angle is it coming from? How much did I pay for it, again?

Let’s first tackle the size of your light. It’s important to keep in mind that you should judge the size of light as it relates to your subject. If you’re shooting full-length portraits of someone, there’s going to be a difference between a “big” light source for that person versus what you’d need if you were taking product shots of cell phones, for example. This boils down to apparent light size; that is, the size of light from the perspective of your subject.

Let’s say you’re taking headshots of someone and you place a bare bulb flash 4 feet from them. Compared to the subject’s face, the size of a bare bulb flash is relatively small. This will yield hard light; your shadows will have very hard, sharp edges and, depending on what angle your light is positioned at, you may accentuate the texture of your subject.

Bare bulb light 4 feet from subject.

Now let’s put a layer of diffusion in-between the bare flash and your subject. This can be done by either holding a white diffusion panel in front of the flash or using a white umbrella. For the sake of simplicity, we’ll assume you’re using an umbrella.

When the light hits the umbrella, the umbrella itself becomes the light source. By nature, the umbrella will cause the light from the flash to spread, effectively making the small beam of light larger. In our current scenario, the umbrella is a large source of light compared to the face of our subject. This will result in soft light, where your shadows have a very gradual fall-off.

White shoot-through umbrella at 4 feet from subject.

Adding in a layer of diffusion will most likely result in a change of exposure. Many people will assume that this change in exposure is what determines whether the light is hard or soft, but that is not the case. You simply have more light coming from more angles. Light coming from the outer surface of the diffusion layer will fill-in the edge of the shadows making the fall-off more gradual. Hence a softer effect.

Bare bulb comparison to white umbrella. In the image on the left, notice the stronger shadows, smaller and sharper catchlights in the eyes, and how the skin texture becomes more emphasized (which can often be an undesired result in portraiture).[ad name=”250×250″]

The distance between your subject and your light source affects the harshness of the light as well. In our current scenario, let’s say that you moved the flash and umbrella 8 feet away from your subject. Because the light is further away, from the perspective of your subject the light has become smaller, thus more harsh.

Many photographers claim that moving a light further away gives them softer light than moving it closer. What’s happening is that, since the light is further away, it’s having more chances to bounce off of walls, the ceiling, and even the floor. In effect, the entire room is becoming a big light source, which is resulting in the softer, lighter shadows.

This can be further demonstrated by the sun. The sun itself is gigantic. Yet, because it’s so far away, on a clear day it has the effect of a small light source and will result in hard shadows.

Now let’s imagine that it’s a cloudy day. The sunlight hits the clouds and they act as a layer of diffusion, effectively making the clouds a bigger light source than straight sunlight and giving you softer light. This is why many photographers prefer to shoot on cloudy or overcast days.

The important things to remember when it comes from the perspective of your subject:

• Small light source = hard light
• Big light source = soft light

Whether you use hard light or soft light is strictly a matter of personal taste. Many consider soft light to be more flattering and appealing, especially in portraiture. In these cases a photographer will place a big light source as close to the subject as possible. However, for more punch and higher contrast, you can get harder light by going with a small light source or moving the light further away from the subject.

When it comes to lighting, there’s really no right or wrong answer; just do what makes the picture look the best.

Related posts:

• Off-Camera flash photography tips – Where to Mount the Flash
• Off-Camera flash photography tips – How to Trigger Your Flash
• Off-Camera flash photography tips – Choosing a Flash
• Introduction to Off-Camera Lighting with Small Flashes

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