Studying Light in Photography

Written by: Jeff

We’ve recently started publishing articles concerning light and how to control it. Most beginners would think that studying light is reserved for professionals but this definitely isn’t the case. Light is the most important topic in photography because, simply put, if there’s no light then there’s no photo.

In this article we will discuss the four main aspects of light that you, as a photographer, need to understand.

Quantity

Among all the aspects of light, quantity is the easiest to control and manipulate. In fact, most of the controls found on your camera is designed for this function. The quantity or amount of light is controlled by your camera’s ISO, shutter speed and aperture. If there’s too much light then you get overexposure and too little will leave you with underexposure.

The photo below illustrates deliberate overexposure or what is called high-key. It shows how a photo would look if large amounts of light is allowed to hit the camera sensor.

CC Photo by ribena wrath
Color/Temperature

Different types of light have different colors. We don’t notice these difference so much because the human eye is designed in such a way that it will automatically negate slight color changes in light. Cameras, sad to say, are not as evolved and are susceptible to all sorts of color casts.

The color or temperature of light is measured in degree Kelvin (K) in a scale which runs from 2500K to 10000K. Light which has a higher Kelvin temperature (5000K and up) has a blue color cast to it. It is also described as being cool. Lower temperatures (2700K or below) have a yellow/red cast to it and is said to be warm.

CC Photo by Ferran Nogues. The photo shows how warm or yellow the light from a tungsten bulb is.
This is where white balance comes in. Simply stated, white balance, is simply removing all color casts caused by different color temperatures. By setting the right white balance on your camera, you will be sure that whatever is white in your shot will remain white even if the lighting is not.

Direction

Light can be either directional or non-directional. Since we can’t see light directly, the only way for us to know whether it’s directional or not is by looking at the shadows. If you find that the shadows in your photo is leading towards the left then you can assume that the light source was coming from the right. You can also say that it is directional. Non-directional light is the exact opposite since you will not be able to tell where the light is coming from. Non-directional light is also said to be flat since the absence of shadows will diminish the subject’s texture and form.

CC Photo by preciouskhyatt. Photo shows directional light coming from the upper right hand side of the frame
There are two ways for you to control direction. The first is physically moving the light source to make the light fall somewhere else. The second is by using a reflector which redirects light.

Quality

The quality of light refers to how hard or soft the light is. Again, we need to look at the subject’s shadow to see the quality of light. Light is said to be hard if the edges of the shadow is clearly defined. On the other hand, soft or diffused light creates shadows that have soft edges.

CC Photo by ottovelo. The portrait was lit with very hard light. You can see that the shadows on the subject’s face is clearly defined.
Controlling the quality of light is probably the most difficult of all. If you have direct control of your light, like if you’re using studio lights, then attaching a snoot or grid will make light harder. Attaching diffusers like softboxes will soften light.

Related Reading:
Some Lighting Tips for Beginners
How to Get Soft Diffused Light From Your Flash
Flash 101: On-Camera Flash
Flash 101: Off-Camera Flash
Light Modifiers 101

Related posts:

1. How to Make a Light Box and Macro Studio for Under $20
2. Some Lighting Tips for Beginners
3. Painting with light!
4. Photography in the News: Groundhogs
5. How to Get Soft Diffused Light from Your Flash

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