Physics/Science of Light (PART 12)

Physics/Science of Light

(How you could implement it + create dramatic compelling art scenes)

Tyndall Scattering

Tyndall scattering is another type of scattering that occurs in nature. Similar to Rayleigh scattering, 'in this type of scattering the blues get scattered more and the reds are allowed to pass through or get entirely blocked out.

Predominately, what happens in this scattering is when white light strikes a surface and causes it to scatter a lot of blue.(diagram of white light coming in and blue being scattered)

This occurs when buoyant particles come in contact with compact particles in a medium. You'll notice this type of interaction when you look at skim milk, it has a fairly blue cast along the edges. The same type of interaction occurs when flour comes into contact with water; it forms a subtle blue cast near the edges. This is the workings of Tyndall scattering. You'll notice this phenomenon also taking place with the exhaust from cars, you can you slightly tell the smoke has a blue tinge to it. Smoke and clouds have a very different appearance from one another, and the chief point of differentiation depends on the Tyndall scattering. The colours that tint the smoke is dependent on the source that created it. If you've ever witnessed a forest fire, you'll notice a strange cast to the sky forming and this is mainly due to Tyndall scattering.

Using Atmosphere for Expression

If we were to change the serene cheery sky in this picture to an overcast sky with a large ominous cloud drifting along it would greatly shift the mood of the scene.

Cloud shape and colour can be used to highlight the emotion and composition of your image.

This is a Hudson river valley painter; the interesting interaction with the glowing white from the cloud converging through the dark foreground clouds causes a very strong emotional effect.

The de-saturated, stormy clouds in this picture convey a gloomy atmosphere.

Various moods can be conveyed through the diverse types of sky and cloud formations. Every one of the sky atmospheres can create different effects to your scene therefore preliminary planning and a strong sense of direction is integral. Arbitrary decision making is not an appropriate tool in creating highly impactful scenes. Every aspect of the scene should be cohesive and involving the presence of thought process and reasoning. For example if you're fan of big puffy cheery clouds and want to place them in a gloomy scene, those clouds properly wouldn't be the right fit for the tone in your scene.

Beams of light passing through atmosphere are a great mood and composition tool.You'll often come across clouds that have beams of light radiating from behind them which can create a divine tone to a scene.

This effect also can be seen with dust particles, the light is shining from behind them and causing them to appear shiny. We don't have a total understanding if they have properties that cause them to sparkle or whether it's the contribution of quantum effects that make them appear as if they're shiny. However, it does have something to do with the Fresnel effect. (make fresnel into link and link them to the fresnel section)

Adding fog always adds mood.Fogs covering only the ground or low-lying clouds add mystery and mood.

Generally speaking, when there's a great deal of particles that's been thrown into the air (ie. splashing water, sparks, fire), it can add a lot of energy into the scene however if this tool is used incorrectly it can be very distracting.Visible particles in the air add both energy and mood.