Light- Science and Magic
A guide to better understanding light in photography
How to Learn Lighting
Lighting is the language of photography. Patterns of light convey information. In photography, determining and utilizing light is both art and technology. Here are three important principles that pertain to light:
- The most important is the effective SIZE of the light source; it determines shadows and types of reflection.
- Three types of reflections are possible from ANY surface; it also determines why a surface looks the way it does.
- Some reflections occur from specific ANGLES; determining where the light should and should not be.
Following these principles can allow you to understand light and how to capture it. Ultimately, successful photography relies on the skill of the photographer, not the camera. A photographer should take time plan. Planning is essential in taking a good photograph. Also, learning a digital editing program can also help anyone become a successful photographer.
The Raw Material of Photography
Photography is the manipulation of light.
What is light? Light is a type of energy called electromagnetic radiation, also known as photons. As it travels it changes in strength. Half the time it is negatively charged, and the other half is positively charged; which in turn, cancels itself equaling a charge of zero. All photons travel through space at the same speed, but their electromagnetic fields can fluctuate faster than others. This change we see presented as COLOR. For example, red light has less energy than blue light. This rate in fluctuation is called frequency; we measure it in hertz (the amount the light that can travel pass a point in a second).
Being able to describe light is the first means to controlling it. As photographers we are primarily concerned with the brightness, color, and contrast of light. Brightness, color, and contrast are the most important qualities of photography.
BRIGHTNESS: The most important thing to the photographer is the brightness or luminosity. At the primary level: if the light is not bright enough, we cannot get a photograph. Luminosity can affect camera noise (grain) as well as the sharpness or saturation of color. Dimmer light is required when trying to capture more effects of the color or contrast.
COLOR: Most pictures are made with white light. White itself comes in a range of colors; the right mixture of red, green, and blue will have a white outcome. The human eye perceives this combination to be colorless. Our digital camera however, can detect these colors by using the color temperature scale which measures the temperature of a color. This measurement unit is a degree of Kelvin, or K for short. A light with a high color temperature is seen as a cool color (such as blue). And likewise, a light with a low color temperature is seen as a warm color (such as red). Digital cameras have a color balance or white balance option that allows you to control the temperature of these colors; for example, Daylight is 5500 K and Tungsten is 3200–3400 K.
CONTRAST: High contrast photographs have light rays that strike at the same angle. Low contrast photographs have multiple light rays striking the subject at different angles. A clear sunny day would exhume high contrast. Hard shadows can help us identify high contrast. A shadow with sharply defined edges is called a hard shadow. Most small light sources are considered hard, and vice versa. Shadows are part of the scene where light doesn’t strike, highlights are part of the scene where light does strike. Lighting is the relationship between the light, the subject, and the viewer.
The subject of the photograph can transmit, absorb, or reflect photons of light:
- Transmitted light is light that passes through the subject; clear glass and clear air are good examples. A subject that only transmits light cannot be seen; they are transparent. But when the light is bent by a subject or in other terms ‘refracted’ it can be seen, like around the curvature of a clear bottle.
- Direct transmission is when light passes in a predicable path. Diffuse transmission is when light rays scatter at random in an unpredictable path. Materials that diffuse light are translucent. They absorb and reflect some of the light.
- Solid subjects absorb light. Although the light is invisible after being absorbed, the absorbed energy still exists in the form of heat. Absorption also effects color and light frequencies, as well as black and white tones.
- Reflection is light bouncing off a subject. Reflection makes vision possible. We do not see objects, we see light.
The Management of Reflection and the Family of Angles
There are three types of reflections: diffuse reflection, direct reflection, or glare. Different surfaces can cause different reflections. Here are further details about the three different reflections:
- Diffuse Reflections are the brightest, because the light is reflected equally in on directions on the surface as it strikes. As a light gets near a subject, the diffuse reflections and shadows cause by hard light increase.
- Direct reflections are also called specular reflections. When the photographer is positioned at the same angle as the reflected light then the subject is the same brightness as the light source. Brightly polished metal, water, or glass produce almost produce perfect direct reflection. From different positions, light hits us at different angles. This collection of angles is called the family of angles. The family of angles produce direct reflection. It also helps us determine where we should place our lights, if any
- Polarized Direct Reflection is dimmer. We see it as a glare. A lake, painted
metal, glossy wood, or plastic can cause this effect.
