How to Turn a Hard Light into a Soft Light: An Important Video Lighting Technique
Video shooters benefit from knowing how to turn a hard light into a soft light, because most people look best under a soft light source. If you’re lighting a person, you’ll notice they look quite different depending on whether they’re under a hard light or a soft light. Here are the five most common ways that I turn a hard light into a soft light.
What is a hard light versus a soft light?
First, we need to discuss the difference between a hard light and a soft light. I’ve noticed that many people can’t look at an image and tell which is which. Here’s an easy way to figure it out:
Look at the shadow’s edge.
- If the edge of the shadow is a hard, sharp edge, then the light source is a hard light.
- If the shadow’s edge is a soft, gradual transition, then the light is soft.
And of course, it’s a sliding scale. You have a very hard light on one end of the scale, and a very soft light on the other end, and a lot of variations in between.
What makes all this work?
The Magic Behind Soft Lights
The main thing to remember is: the bigger the relative size of the light source (compared to the subject being lit), the softer the light.
Keep in mind that I’m not talking about light intensity here. That’s something different. It’s true that sometimes when you soften a light, you also reduce the intensity, but when I talk about hard and soft light, this is what we refer to as the light quality, or the quality of the light.
Remember that it’s the relative size of the light source, not just the size. As an example, if we used a regular household style tungsten light bulb to light my face, and we held it three feet away, it would be a small light source relative to the size of my head. My head is much bigger than that little light.
However, if we use the same light bulb to light the face of a Barbie Doll (whose head is, yes, much smaller than mine), then the resulting light will be a soft light. The bulb, even at 3 feet away, is still bigger than the doll’s head.
It’s the same bulb. The only thing different is the relative size of the light source compared to the subject. The bigger the relative size of the light source, the softer the light.
If you want to soften the light a little, but not too much, you can clip a piece of diffusion paper over the front of it. Barn doors are great lighting accessories, because not only do they help you control spill light, they also give you something to clip your diffusion paper and color gels to. Most people use regular clothespins for this.
A piece of opal, or frost, can be a great thing to clip to the front of the light, and this will increase the size of the light source. It will also reduce the intensity by stopping some of the output, but remember there’s a difference between light intensity (output) and light quality (hard or soft).
Bounce light, sometimes called a reflected source, can be a great option for softening a hard light source. To use this lighting technique, you need just two things:
- a light source that you can aim
- a reflective surface to bounce off
A common option for bouncing light is a white foamcore board. You can purchase sheets of these from your local craft store for a couple dollars each. They’re easy to use and extremely handy. My only complaint is that they don’t last long, so you’re constantly replacing them — but hey, they’re only a few bucks each, right?
You can use nearly any kind of surface. To soften the light, it should be a white surface so it doesn’t introduce additional color into the light. (Don’t use a shiny surface such as a mirror or aluminum foil, unless you want to blind your subject.)
If I need a bounce surface bigger than the small foamcore boards, I’ll usually pull out a diffusion panel with a reflective fabric on it, and use it instead of the foamcore.
When you watch behind-the-scenes footage on DVD’s, you’ll sometimes see large panels of white fabric suspended over the actors outdoors. These are large diffusion panels. They consist of a frame and a fabric. The fabrics are removable so you can swap them out with various levels of diffusion. Light diffusion will let the light pass through without changing the quality much, and heavy diffusion will change the light quality dramatically.
Smaller 42”x42” diffusion panels can be a good option for diffusing light indoors too. To use them, simply put the diffusion panel between the light and your subject, and then “punch” the hard light source through the fabric. This will diffuse the light, softening it, and it turns the fabric itself into the new light source. Because it’s a much bigger relative size, the light is now a soft light.
You hear a lot about people using other kinds of materials instead of actual diffusion fabric. I’ve heard of people using bed sheets, window curtains, even shower curtains as diffusion fabrics. While these are certainly inexpensive options, be warned that..
- They might be highly flammable and catch fire if they get close to the hot light source
- You probably don’t want to bring a shower curtain along with you if you’re doing client work. You probably wouldn’t do that, but just in case you were considering it… :)
My favorite way to soften a hard light is to put a soft box on it. One of the challenges of working with soft light is that it goes everywhere, which isn’t good. To paint with light, we need to control it, and a soft box gives you the best of both words. It’s a soft light, because you can get a big soft box which will give you a nice soft light. And it’s also something you can aim — especially if you put a fabric grid (sometimes called an egg crate) on it.
A soft box is a fabric box that mounts on your light. The light is inside the box, surrounded by four opaque “walls”, and the front of the box where the light comes out is nothing more than a diffusion fabric, similar to the fabric on diffusion panels.
Soft boxes are the most expensive way to turn a hard light into a soft light, but if you’re shooting video of people, they’re a necessity. There’s nothing else that gives you the light quality and the control the way they do.
I almost always use a soft box on the key light when I’m using three point lighting.
An Easy Option to Forget
One last option that I frequently use, but it can also be an easy one to forget — maybe because it’s so obvious?
You can move the light closer to your subject to increase the relative size, or move it further from your subject to decrease the relative size. In other words, move it closer to soften the light, or further to harden the light. (Keep in mind this will also change the intensity of the light, so you might need to adjust your video camera settings to get a good exposure.)
Can you soften the light other ways? Sure. You can bounce it off the ceiling and walls. You can toss white fabrics on the ground and bounce the light off them. You can put a light inside a china ball.
You have many options, but my goal here is simply to introduce you to the most common ways that I turn a hard light into a soft light.