Light : The Science of it All
Light. Learn to understand it, learn to see it and the better you’ll be able to manipulate it. After all, the whole science behind photography is based on the principles of light. Stick it out through these next three days and things will get a lot more interesting. Before you can learn to manipulate light (or if you’re a curious person like me,) it’s good to understand the “how” and “why” behind it.
So, welcome to the science of light.
(I know this is the boring part, just stick with me…)
Light and Color Science:
The human eye is only sensitive to the visible spectrum of the electromagnetic spectrum. White light contains all colors. We learned this when Newton split white light with a prism.
Additive Primaries – Red, Green, Blue
When you add equal parts of the additive primaries together (Red, Green, and Blue), you create white light. RGB is the color method used in today’s digital world. Mixing just two of the additive primaries will result with one of the subtractive primaries.
Subtractive Primaries – Cyan, Magenta, Yellow
The subtractive primaries absorb their compliments (RGB) and subtract them from white light. CMYK is the color model for printing (K referring to Black). When subtractive primaries are mixed, they subtract brightness from white, resulting in Black.
Each additive color has a subtractive color that is its compliment.
Red – Cyan
Green – Magenta
Blue – Yellow
Before you can learn to modify and use light, you need to understand how it works! The first things to be conscious of are the qualities of light which include direction, contrast, color, brightness, diffused, and specular.
Direction is where the light is coming from. This controls the relationship between light and shadow. Direction can also be understood as the position or placement of the light.
Contrast is the relationship between light and shade.
Color is the color temperature or actual color of the light source. (We’ll get into this in a minute.)
Brightness is the intensity of the light.
Diffused light is a softer light typically produced by a larger light source.
Specular light, in short, is light from a source that is not modified. Most of you guys will refer to this as “harsh” or “hard” light.
How can you tell if something is diffused or specular? Look where the shadow meets the lighted areas. If the transition is gradual, it is diffused. If the transition is knife edge its specular. Aka – Does the shadow end very abruptly? Think of high noon light and how the shadows cast by the sun are very crisp. This is specular light.
The size of a light source (as relative to your subject) will greatly effect the type of light produced. A small source will produce hard light, hard edges and harder shadows. A large light source will produce a shadowless or softer light with softer shadows.
Distance also effects your light. A light close to your subject will create a softer light, whereas the same light when placed farther away will create a harder light. Think of the sun! It’s far away, appears quite small but produces an extremely harsh light/shade relationship unless there are clouds to diffuse the light. When the sky is overcast, it acts as a giant soft box for the sun.
We’ll dive a little further into distance and light tomorrow.
Until then –
Feature image & image 1: AT
Image 2, 3, 4 & 5: AT
Image 6: 150m.com