Back in college, I was taught there were two ways to light a subject with strobes or flashes. You can make the light part of the story of the image, showing how interesting and dynamic it is. On the other hand, you can blend your lighting in and make it appear completely natural. Both tactics are challenging to do well, but after following this tutorial, you should have a better handle on recreating natural light with flashes.
Hiding Your Lighting
Some amazing advances in lighting have been made in the last couple decades. There are smaller, more mobile kits. There also have some adventurous folks pushing the limits and creating stunning images. When we look at these images, we're seeing something in a new way, under lighting conditions that are wild and inventive.
However, it's sometimes just as challenging to make things appear as if they aren't being lit. Not every subject or situation calls for the dramatic beams of a spaceship.
The funny thing about natural light is that is does what it wants, and often times doesn't make for the best pictures. It might be shady where we want sun. There might only be a desk lamp where we need a window. Those overhead office lights might be flickering and dim. You need to know how to overcome these problems, but still keep in real.
Before we start recreating natural light, we need to understand its qualities.
Natural Light Sources are Not Usually Soft
The sun is very tiny dot in a very large sky. Light bulbs are no bigger than your hand. The fact is that most natural light sources do not produce soft light. Yet, when we think of the lifestyle and magazine photography that relies on natural-looking photography, we don't see really harsh, dramatic shadows. There are three reasons for this.
First, the softness of natural light comes from the environment. Indoors, you'll mostly find light colored walls. This allows the light to bounce around the scene. If you're in a room with four white walls, a white ceiling and light carpeting, you're essentially in a giant light tent. Outside, the sunlight bounces around, too.
Second, natural light sources project their light in all directions. When we use strobes, they shoot light in one direction. Most other light sources cast their light everywhere. This combines with the reflective environment to create a bit softer look.
Also, in most indoor environments, there are multiple sources of light. You may have a several different light turned on. You may also have lamp light and window light mixing together.
Natural light sources are usually further away than we would place a strobe. If you're inside, windows and overhead ceiling lights are literally as far away as light sources can be inside the room. Now, you may have been taught that the further away a light source is, the harder the light becomes. This is true, but the distance lets the light to spread out more allowing it to bounce around more.
Distance also affects the inverse-square rule. The further the light is away from the scene, the less falloff there will be. In other words, if your light source is five feet away from your subject, things seven feet away might be a half or a whole stop under exposed. If your light source is 15 feet away from your subject, things 17 feet away will probably still be properly exposed.
Natural Light Produces Even Exposures
In addition to producing a softening effect, the qualities I listed above also produce even exposures. Often, when we decide to use strobes in our work, we want the subject to be in pool of light, brighter than its surrounding. However, this doesn't typically happen in natural light situations.
When you're working inside, I call this type of light "room filling." Natural light evenly illuminates the whole room, something that a flash might have trouble doing if not used properly.
Achieving a Natural Light Look Outside
So now that we have a firm grasp of the qualities of natural light, it's time to replicate them with artificial light. When you're outside, you want to choose a lighting set up with produces slightly soft light, but nothing too big. I often use a 36 inch umbrella. The light from the flash won't be able to bounce around like sunlight does, so we do need to soften it a bit.
You may notice something else in that previous image. Often, the key to making your light look natural is to utilize some of the light from the environment. By balancing our artificial light with the light that's already in the scene, you can make your images look more natural.
Case Study: A Senior Portrait Shoot
Let's take a look at two images shot during a senior portrait session in a creek. I like both of these images, but one has a much more natural look it.
With this first picture, I used the same type of lighting set up as the engagement shoot. The subject is well lit, but there the light isn't so soft that it appear unnatural. However, there's a big different between the exposure of the background and the subject.
Some may say that this image isn't as good as the first version, but there's no arguing that it looks more natural. By simply changing my shutter speed (this setting doesn't affect flash exposure), I was able to raise the exposure in the background.
Matching the Angle of the Natural Light
Obviously, when possibly, you'll want to attempt to match the angle of the light, but in most cases, this won't be possible. If the light were coming from the exactly the right angle to begin with, you wouldn't need a flash at all.
Most of the time, I choose to shoot in shady areas where the sun's angle is less noticeable, like the previous images.
The next photo is an example of what not to do when trying to make your photos look natural. In this image, I was shooting into the sun. I used my flash setup to light my subject normally, but the telltale glow of the air is a sure sign the image was lit. There's no hiding it. That's not to say it isn't a pretty good image, it's just not the most natural look.
Achieving a Natural Light Look Inside
Inside things become a bit tricky. Normally, the light inside is dim. Using any flash at almost any power is likely to overpower it. Indoor lighting also has color temperature problems. Most household lights require a very different white balance setting than flash.
To make natural looking light inside, it's best to create it all or most of it yourself. This may sound overly simple, but I find bouncing a bare light off a wall or window is very effective.
Case Study: A Holiday Portrait
A couple I'm friends with asked me to make a portrait of them to give as a gift to their parents. They didn't have anything particular in mind so I decided to go with a classic, natural look.
Let's run through all the necessary steps to get the look right. I used a bare flash pointed straight at the window off the left side of the frame to create a light that bounced all over the room. By bouncing your light off the window, you're automatically matching the angle that light would naturally be traveling. The window was about 12 feet away from my couple. This lit the scene evenly.
The room was very long from the left side to the right side. My flash wasn't bouncing enough light on the right side of my couple, so I added a second flash. This one was also bare and pointed up at the ceiling. It filled in the shadows on the side of their faces a bit, and also created at room filling light we're looking for.
There was also a small opportunity to incorporate some natural light. I exposed for the highlights of the scene to establish a baseline.
After getting my baseline, I turned on my flashes and I adjusted the power to fill in the rest of the scene.
I love that there is nothing in this picture to distract from the couple and moment.
Keeping It Natural
I hope this tutorial gives you some tips for creating natural looking light. There's really only a few things to remember. When you're outside, soften up your light just a little. Also, shoot in areas where the direction of the natural light isn't obvious.
The most important thing to remember when outside is to balance the natural light and your flash appropriately. Our natural inclination is to underexpose the natural light to draw attention to our subject, which works fine in some cases. However, to make the lighting look natural, you need to expose the background properly and draw attention to your subject through composition.
When working inside, remember to fill to room with light. The easiest way to do this is treat your flash like a really powerful lamp. Let the light bounce around the room in all directions. Place it where you want it and let the walls do the rest of the work.