Tuesday, February 21, 2012

Direct and Indirect Light

Posted by David Peterson on 16 Feb 2012 as Tips
 There are two types of light in this world; direct light and indirect light. Each of them serves a unique purpose in photography, and each has its advantages and disadvantages. Direct light is straight on, sometimes harsh and sometimes warm and colorful. For example, without direct light, the image to the right wouldn’t be nearly as colorful. Indirect light comes from all sides and completely illuminates your subject. Let’s take a moment and consider how each might be useful in your own photography.

What’s with the distinction?

If you really think about it, there is no fundamental difference between direct light and indirect light. One is simply the overabundance of another. When you say the light is direct, you are saying a lot more about what isn’t happening than what is. Direct light is the absence of light on any other side except the side with a single light source.

Indirect light, by contrast, is light coming in from all sides. Technically speaking, there’s always some small amount of light bouncing around and hitting your subject on all sides too. The difference with indirect light is that it is more evenly balanced. In other words, the light reflecting onto the other side of your subject is nearly the same intensity as the source itself.

Most indirect light isn’t completely indirect either. The original source is usually a little brighter than the sources of reflected light. To see what I mean, just think of an overcast day. We would say this is an indirect lighting situation, but if you look at the sun, it’s still brighter than anything else around. The real difference, then, is the degree to which it is bright. On an overcast day, it’s relatively less bright than on a fully sunny day.

How to prepare for each shooting situation

Why is that important to note? Because even though you can’t see any shadows, the light is never perfectly even. On an overcast day, you still need to pay attention to the angle of the sun (mostly as a means of avoiding backlit photos). As long as your subject isn’t directly in front of the sun when you’re shooting, you can shoot at any angle you like. 
 Overcast days are ideal for portraits.
The lack of shadows brings out the smoothness in faces, making
people appear younger and more attractive.
Photo By Jon Clegg
Direct light is rather different altogether. You have to make sure the light is shining right on your subject, and you need to double check your photos for unwanted shadows. There is no other place this could be more true than in portrait photography. Shadows get misinterpreted as wrinkles and fine lines. If you use direct light, you run the risk of making your subjects appear much older than they actually are. That’s no way to sell you friends on your photography skills!
However, if you were to take that same direct light and use it to photograph food, then you’d really have something. One thing that really sells us on food is its texture. When you the right kinds of shadows (something you can only get with direct light), food appears more textured and therefore more appealing. Without shadows, all food looks the same.
What are the best things to photograph in direct light?
  • Landscapes. Do this in the early morning. The shadows give the mountains the texture they need to stand out and take center stage. It’s hard to read the geography and depth of a landscape without the shadows, and that’s why direct light is so ideal for this situation.
  • Still Life. It depends on the subject matter, but direct light does have a number of advantages over indirect light. If your subject has an interesting texture, direct light is definitely the way to go. Food photography is a sort of still life photography, and it demands direct light.
  • Silhouettes. Just position the sun behind your subject and shoot away! Silhouettes convey an air of mystery that you can’t quite get with indirect light. Plus, if the light of the sunset were indirect, you wouldn’t get any of the beautiful colors either. Oh, you might need to use a flash to ensure your subject is lit from the front too.
What are the best things to photograph in indirect light?
  • Portraits. Too many harsh shadows on either side of the face can make a person appear much older than he or she actually is. In other words, it’s a bit unflattering. Unless you are intentionally trying to emphasize someone’s age, stick with indirect light.
  • Macro photography. Most people don’t know that cloudy days are perfect for shooting flowers and other life close up. It really brings out the colors.
  • Products. Excess shadows can make products appear unappealing. If you ever sell anything on Ebay, make sure you setup a softbox and use indirect light to illuminate your subject.

Food photography is the delicate art of fine-tuning direct light to get perfect shadows. Indirect light would make the ranch dressing look like an amorphous white blob. Not so appealing to would-be eaters.

Make your own indirect light

The goal of most studio photography is to turn direct light into indirect light. To this end, photographers spend money on reflectors, L.E.D. lamps, beauty dishes, and a number of studio gizmos. You don’t need to buy all of the equipment in order to create your own indirect light, but it certainly will make your job easier. Instead of spending a bunch of time searching for something to reflect the light, they can simply bring all the gear with them.

A single white paper towel is enough to turn your flash into a source of indirect light. Just place it in front of your flash, and it will disperse the light in all directions around your subject. I also find it helpful to use a small reflector to bounce my flash toward a white wall. Direct flash is the worst kind of direct light. It’s too intense and focused, often making your scene appear uneven. By using a reflector, you are forcing the light to the side, making it indirect.

If you don’t have any reflectors on hand, you can always use a mirror. They work perfectly fine. The only issue is their heaviness. Reflectors are nice because they fold up, don’t shatter, and they give you a nice diffused white light (mirrors simply reflect all light). This is the poor man’s toolkit until you finally buckle and buy a few accessories.

As you can see, both direct and indirect light have their place in the world of photography. One is not better than the other. They simply have different purposes. If you are trying to emphasize texture and shadows, go with direct light. For everything else, use indirect light.

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