Reflected light and how it impacts your photos.
Tags: Smugmug, Light, Photography Tips, Tips, Reflected Light

Without light, photography doesn’t exist. And knowing how light works and interacts with your subject — and with your camera — will make you a better photographer.

When it comes to light, there are two types you should be familiar with: incident light and reflected light. In this post, we’ll take a look at reflected light.

Reflected light is light that’s reflected off a subject. No matter what direction the light is coming from, it will be affected by what it’s bouncing off. The subject will determine which type of light will be reflected. Keep in mind that reflection of light isn’t the same as refraction.

The difference between reflection and refraction.

When light strikes a medium and bounces back, that’s reflection. Any object you can see is visible because of reflected light, even if you don’t think of the object as “reflective” like a mirror. We’ll get to the specific types of reflected light in a moment. But first, reflection is commonly confused with refraction, which is when light passes through a medium and changes direction and speed.

A good example is when you use a refraction ball or shoot through a water droplet. The subject or landscape on the other side is inverted and skewed by the shape of the refracting object. Light passing through a prism or a camera lens is another example of refraction.

Now that you know the difference between the two, let’s jump into the reflection of light and how it applies to photography.

Types of reflected light.

The reflection of light can be broken into two categories: diffuse reflection and specular reflection. Diffuse reflection is light that hits a surface and is reflected in many different directions. Almost all light you see on a daily basis is diffusely reflected.

Specular reflection is light that hits a smooth surface and is reflected at the same angle. An example of specular reflection in photography is taking a picture of a reflection in a still body of water. In the photo above, the water is creating a specular reflection of light, and the forests and mountains are creating diffuse reflections of light.

Specular reflection follows specific rules known as the laws of reflection.

The laws of reflection.

When light hits a smooth surface like a mirror, it always behaves in the same way.

Law #1: The incident ray, the reflected ray, and the normal line (the line which divides the incident and reflected rays into two equal angles) all lie in the same plane.

Law #2: The angle of reflection equals the angle of incidence. Think of bouncing a ball off a wall. The angle that it bounces back at is determined by the angle thrown at the wall.

Law #3: The reflected ray and the incident ray are on opposite sides of the normal.

Reflection of light in photography.

Knowing how light reflects off different subjects will allow you to overcome potential problems like hot spots or red eyes. Hot spots are areas in an image that are much lighter and brighter, and they’re caused by specular reflection.

A shiny nose or forehead, glasses, windows, or other highly reflective surfaces can cause these spots. Using the law of reflection, we know that moving the light source or camera to a different angle will help eliminate these spots. The same goes for red eyes.

Light is the most important element in photography, and the better you understand how it works, the better your photos will be. By mastering the reflection of light, you’ll be able to take better shots and avoid common issues like red eyes, hot spots, and blown-out exposures.