Understanding light is the key to creating images in photography. The word photography come from two Greek words photos or light and graph meaning to write or draw. Therefore, photography means to draw with light. Read any book on photography and much of it will be devoted to light.
Light makes photography.
But above all know light.
Know it for all you are worth,
and you will know the key to photography.
(George Eastman 1854 – 1932) (4)
The Science of Light
Have you ever wondered why you can see light, see colour or hear the radio, watch the TV or even heat your soup in a microwave oven. This is because of a form of energy called “electromagnetic (EM) radiation”. EM is like the waves at the beach. Sometimes the waves at the beach are just a ripple, at other times they can roar in at great speed. The sea waves can be long or short. The length of the wave of EM determines whether it is seen, heard or invisible. You cannot see many of the different EM waves, but we can hear radio waves and we can see visible light waves.
When you see a rainbow, you see the different colours within visible light. The light rays are scattered across the sky and clouds. Under specific conditions the light waves are bent when passing through water droplets in the sky. This allows us to see the different light waves. Each light wave is a different length and our eyes see these waves as a different colour.
We can bend light by using a prism to demonstrate the breaking up of the light to see its many colours.
Quantity and Intensity
The quality and intensity of light is determined by the source and direction of the light. It might be produced by the sun, a reflection or an artificial light source e.g. a light globe. Depending on the direction of the light, the texture may stand out or be enhanced. Colours will be brighter or darker depending on the level of light.
You create images that change depending on the different lighting conditions. For example if you are photographing a landscape on a sunny day, it will often involve light of high intensity. However, on a cloudy day the light is diffused or spread out and therefore less of intensity, thus creating a different image.
Consider the light at midday on a bright sunny day compared to the light in the evening of the same day. When creating images on a sunny morning the light might be considered hard or harsh. Very bright days can be challenging for a photographer despite many people thinking that these days are ideal conditions. However, when it is very bright, there is less detail in the image and the difference between light and shadow is great.
When we think about contrast in photography, we are considering difference between dark and light or between light and shadow. It
also means the way light affects the colour, tones and texture of the images we are creating.
How does light affect colour?
When a wave of light hits an object, the object absorbs some of the light and reflects back the left over light. The red square in our image absorbs most of the light, but reflects back only the red light waves. Whereas the yellow square absorbs the light but reflects back the yellow light waves.
Let’s take an everyday example. When you look at a red apple the white light from the sun reaches the apple.
All the colours are absorbed, except the red. The red is the colour that we see. If it was a green apple all the colours would be absorbed except the green. (2)
A white object reflects back nearly all the light and a black object absorbs nearly all the light. You cannot see any colours in a completely darkened room because there is no light to produce colour.
All colours simply come from the different wavelengths of light which bounce off the object.The light from the sun, for example, is a white light. We can see that it’s made from all the colors in the rainbow, when the sunlight is broken up by water droplets.
Colours also change depending on intensity, quality or strength of the light source. They may appear brighter or darker depending on the light and light source. They absorb or reflect the light depending on the circumstances.
The image is the same but taken under different light conditions. The two middle images have subtle differences.
There is a marked difference between the first and the fourth image. (Click on the image to enlarge)
For more information on colour click here.
In the next section we discuss the “Golden Hour” and the “Blue Hour” to show how light affects colour.
In photography, the golden hour is shortly after sunrise or before sunset, during which the light is warmer and softer compared to light in the earlier part of the day. Consider the light on a hot summer’s day and the light at sunset later on the same day.
The golden hour is not the same in every place. For example, the golden hour in Brisbane is different from here in Adelaide. When we say the “golden hour” it does not really mean that it lasts an hour as it depends on the location.
In fact in some parts of the world the golden hour lasts for the entire, day depending on the seasons.
Because the golden hour is based on the sunrise and sunset you may need to plan when you will create your images.
Click here for a calculator the help you determine the golden hour on any given day.
Like the golden hour, the blue hour is not strictly 60 minutes. Rather it refers to the period just after the sun sets below the horizon or just before the sun rises. As you can see from the image on the left the light is a deep blue and influences the composition.
To determine the “blue hour” for your area click here.
What does this mean for Photography?
In considering our composition we should ask the following about the available light:
- Where is the light in the scene we are looking to photograph?
- Where are the shadows and what effect are they having?
- What is the source of the light? As you have seen from the pencil image, different sources of light will change the scene. Consider if you were photographing a person out in the daylight and compare this to if you were photographing them in a room under fluorescent lights.
- How would you describe the light? Harsh or soft, do we need to diffuse or add to the light?
- When we consider the light creatively we look for shapes created from the interplay between light and shadow.