Without light there is no color. This sounds obvious, as without light we can’t see the colors around us. But that’s not the only reason. In fact, color is light. Or rather; light is color. The white mid-day sunlight is a mix of all colors. So in relation to colors, this light is the “easiest” for photography. But even though the sun is our main source of light, there are so many environments where other light sources has to be taken into account. These light sources contain various amounts of the color spectrum.
Smoke on the water, by Marius Waldal
A multitude of light sources
Depending on your environment, your surroundings are lit by different sources of light. If you’re indoor, your light source may be fluorescent light, incandescent light, candlelight, a window, or (often) a combination. Outdoor, apart from the sun, your scene may be lit by street lights, fluorescent light or even moonlight.
These various lighting conditions call for some care when photographing, as they all have their specific characteristics. I will guide you through these common light sources and offer a few tips on the way.
The difference between the eye and the camera
It seems prudent to first say a few words about how the camera sees light compared to the eye. Our eyes have an impressive ability to adjust to the available light, trying to achieve some kind of “normality”. Even light with a strong color cast will appear a lot more normal (white) than is really the case.
Not so with a camera, which will record the light as it is. This is why your camera has a white balance control that will try to simulate what your eyes do; “normalizing” the colors in the scene. For several common lighting situations, this does the trick. But some situations, like when you shoot scenes lit by street lights, call for more thought. Learn why below.
The most common light sources
Natural light
Even though natural light is as simple as being only 1 light source – the sun – it is also the most complex type of light, and by far the one with most varieties. There are so many factors that affect sunlight (clouds, haze, temperature, season, time of day, reflections to name just a few), each with their own distinct effect on color. Actually, this subject is so vast that I will dedicate another article to natural light alone. Here I will limit myself to just a few basics.
Untitled by tbg78 on Flickr
This is a great example on the warm colors of evenings. This silo is actually gray, but when hit by the late evening sun, the sunlight paints it orange.
When sunlight (which is more or less white because it includes all colors) hits the atmosphere, some of this light scatters. The short wavelengths scatter the most, and these are at the bluish end of the scale. In the morning and evening more blue light is hindered, causing the remaining light to have a warm red or orange color cast. During the day, the sunlight passes through less atmosphere causing more blue light to hit the earth, and this creates a cooler color cast (often bluish because of reflections from the blue sky).
Different types, and amounts, of clouds affect sunlight in a multitude of ways. Most surfaces reflect sunlight, in various amounts. Depending on these surfaces, the lighting conditions may vary greatly. The weather can be hot, cold, bright, dark, rainy, misty etc, which affect the light in their distinct ways. Even when the sun is gone at night, sunlight hits the earth via the moon (which does not produce its own light but merely reflects the sun).
If you add to this the various angles to the sun or reflecting sources both you and your subject may have (and often, your camera is the only factor where you have control of positioning), you may appreciate how numerous the lighting conditions of natural light are. So stay tuned for a follow-up article on the subject of natural light!
Ever wondered why the sky is blue? You may already have read the explanation in the text above: It’s because the atmosphere scatters the blue wavelengths from the sunlight, causing blue light to reflect upward. From our viewpoint on Earth, this creates the equivalent of a huge blue reflector in the sky. While this is beautiful to look at, be aware that the sky also throws a bluish color cast down on Earth, which is especially visible in shadows.
Glowing light sources
Bulbs based on heat (tungsten lamps) – incandescent light – have for a long time been (and still is) the most common source of light in our homes. We are so accustomed to the warm yellowish light created by these lamps that we perceive it as fairly white. But our camera records the yellow color cast as it is. This is sometimes desirable, as it creates a warm, cosy effect. But more often this effect is not what we want, forcing us to adjust the white balance accordingly. As this kind of light is based on heat, the color temperature in the Kelvin temperature scale is pretty low; between 2500K-2900K (not unlike sunlight at sunrise and sunset).
Even warmer is the light emissions from flames, like candlelight or a fireplace. The white balance setting for tungsten usually works well with candle-lit interiors, but as the temperature of candlelight is just below 2000K, even more adjustment may be warranted.
Fluorescent light sources
Another light source that is not uncommon in private homes and very common in office landscapes, shops, malls and other public indoor areas are fluorescent lamps. To our eyes this light looks all white, without much “automatic adjustment” by our eyes. But to a camera, this light has a green color cast. Most people will react negatively on a greenish photo, as green is often associated with sickness and decay, so a white balance correction is most often warranted.
As always, shooting in RAW will reduce the need for choosing a correct setting, as the white balance can be easily adjusted in post-processing. If you shoot in JPG, however, you will need to take into account the fluorescent lighting in your white balance settings. Be aware, though, that fluorescent light sources may wary greatly according to the effect the manufacturer is trying to simulate. The amount of green varies from almost nothing to a stark cast. A manual correction may be necessary.
Vapor discharge light sources
Vapor discharge lamps are on the rise. They are not new, but are gaining momentum over fluorescent lamps in many indoor lighting situations. Outdoor, they are the most common lamps for street lights and for floodlights (buildings, parking lots, stadiums etc). The two main types are sodium-based and mercury-based.
Sodium is most commonly used in street lighting. They have a strong yellow color cast, even to the eye.
Mercury-based lamps are not so easily distinguished, as they appear a lot whiter to the eye. On a photo, however, the color cast is quite green.
In some places where a more balanced spectrum is needed, like in a stadium where television cameras are used, a mixed (multi vapor) type is used.
What is special about this type of lamps, is that they peak strongly in a small part of the spectrum (like yellow or green), and at the same time are completely devoid of other parts (most notably blue). This is very obvious if you convert such a photo to monochrome and use the tonal sliders to adjust the photo. You will often experience that adjusting the blue (or similar) slider has now effect, as no blue light has been captured by the camera.
In some cases, the green color cast is so intense that it is very difficult to adjust it properly (mainly due to the very limited color spectrum available). In such cases, I recommend converting to monochrome; either as a black & white image, or choosing a psychologically more acceptable color than green; typically yellow (which is usually accepted by most people, due to familiarity created by the yellow color casts of evening sun).
Mini case study: Street lights
As you can see, the original (shot with daylight WB setting) has a stark yellow cast. At the far back, you can see a car approaching. These lights are also a bit yellow, but a lot whiter than the street lights.
In the second version, I’ve dragged the white balance setting down to 2500k. The street lights are still not entirely white, but looks reasonably normal. What’s also happened, though, is that the headlights on the car have now turned blue. In addition, the lights in the windows of the building all the way to the right have a green cast.
In this particular photo this setting would work ok, since both the headlights and the window lights are so small and unobtrusive. Had the car been clearly visible, we would be less inclined to accept the unnatural look.
The third version shows how these challenges can be avoided by choosing monochrome treatment. There are no important colors in the image that call for using a color version. On the contrary, as the bright yellow neon sign (which IS a yellow sign!) demands too much attention (as discussed in this article). By choosing monochrome, this bright yellow light becomes just another light.
Multiple sources in one scene
Life is usually not simple. Often, your scene contains multiple different types of light, and this may create complicated situations for photography. Compromise is often necessary, depending on how much control you have over your scene.
The first thing you should do is shooting a test frame to see the different color effects your lightsources create. I recommend using the daylight white balance setting for this.
If you can control your scene and some sources are especially troublesome, turning them off may be necessary.
If you can’t control your scene
If the main part of your scene is lit by one type and the other types only represent small parts of your scene, adjust for the main source. Small sources of light that look unnatural are usually acceptable.
If your scene includes daylight (i.e. from a window, especially if you can see through this window in the frame), your best option will probably be a white balance setting that will ensure this light looks natural. This is because people viewing your photo will have less tolerance for an unnatural appearance of daylight than any artificial light source in the scene.
Without natural light, you need to analyze the scene and decide on which are your key tones. Depending on what type of light source lights this part, adjust your white balance accordingly. Shoot another test frame and analyze the scene again. If this setting works for the key tones, what about those parts of the photo that are lit by other sources? If these now look even worse, you may need to experiment with your settings and select a white balance that creates the most acceptable blend of color casts in your photo. As already mentioned, yellow is usually preferable to green.
Conclusion
The subject of light and color is great. In this article I hope you have learned a little on how different light sources affect your photos, and how you might handle it. Of course, trial and error is key. Sometimes, like in the photo of the Brooklyn Bridge above, the color cast is desirable, as it contributes to a certain mood in a photo. Whenever you walk around in the evening, with or without your camera, train yourself on seeing the colors on different light sources around you. Happy shooting!
And don’t forget: I would love to read your thoughts or insights on this subject in the comments section!
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framedreality.com is founded by Marius Waldal, long-time photo enthusiast.