Reflection is when light bounces off a smooth or polished surface. Reflected light is caused when an incident ray (light from a source) bounces off of a smooth surface with equal properties. The reflected ray will mimic both the speed and angle of the incident ray, the clarity of the reflection will depend entirely on the surface material or texture.
When incident light bounces off of a smooth surface, the reflected light travels at the same speed and angle as the incident light. An example of a good reflection is that of a mirror or the surface of water. The reflected ray will reflect more accurately depending on the smoothness or material properties of a surface. With mirrors particularly the surface is completely smooth and polished, making the reflected light directly bounce off the surface at a clean speed and angle, replicating that of the incident ray perfectly. That is how we see clear reflections in glass mirrors or other highly polished surfaces. The properties of water are also good for clear reflections however the texture or unevenness of the surface can distort the reflected image. For example ripples or small waves that interrupt the incident light will alter how the reflected light reacts. When a light source reflects off a rougher surface such as rippled water the laws of light don't change, however the reflection from the surface appears distorted. This is because there is no longer one angle being reflected as the incident light is bouncing off of all the uneven surfaces. This creates multiple reflected rays which will distort the reflection.
Refraction:
The speed and angle of light can change when it passes through a material or object, but the laws of light are still obeyed. When light travels through an object that is transparent such as water or glass, the direction of the light changes as it passes through the surface, bending it's direction and altering the way we see things. A good example is when you place your hand underwater, the light direction is bent distorting the image of your hand under the surface. The same happens with a straw in a glass of water also. The direction of the straw alters slightly once it comes in contact with the water (from air to water) this is a visual representation of how light is refracted within those sorts of objects/materials/surfaces.
Diffused Light:
Diffused light acts in similar way to how light is reflected off of a rougher surface. Incident rays bounce off of multiple surfaces creating many reflected rays. Depending on the property of the object will depend on how we see that information. For example because of the molecules in water, we see reflections clearer although it is distorted. This is because of the properties in water that reflect light in a more complete way. However, although all light is reflected or bounced in some way, Diffusion is a representation of light that has been partially absorbed and then scattered in multiple directions. The type of surface and its properties will change the amount of light that is absorbed and scattered. Alterations in colour and the type of reflected source light can create Specular Diffusion, which is a lot brighter and illuminates more vividly. Standard diffusion is a regular occurrence with light, how a room is illuminated is primarily through the source light being bounced off all of the surfaces in that room. How certain objects are illuminated depends on the amount of diffusion. The closer an object is to a light source, the more light is absorb, broken and then scattered, making the luminance of the object greater. As the light source is distanced from a surface, the diffusion lessens as there isn't as much light to be absorbed and scattered. Diffused light also illuminates other surfaces around it depending on the intensity of the light source and it's material properties. This is an example of 'Bounced' light.
Bounced Light:
Bounced light is when a surface reflects a light source and scatters information to other objects. A room can be entirely illuminated by one light source, but it isn't the light itself that makes the room more visible. It is because of surrounding objects or surfaces reflecting the light source off each other that makes that area illuminated. Depending on the properties of the objects or surfaces in that room, will depend on how much light is being reflected or 'Bounced'. For example a room entirely made of marble, is more likely to be brightly illuminated that a room made entirely of wood. This is because the surface structure and material of marble reflects light cleaner, making the reflected light information similar to that of the incident light (light source).
Subsurface Scattering:
Subsurface Scattering is when an object absorbs light and scatters the information within its structure. This varies entirely on the properties and densities of the object. An example of Subsurface Scattering is within a leaf. Leaves absorb light and scatter that information within itself, illuminating the inside. This type of light can alter depending on the properties of an object, an example of an object with a higher density is our ears. Ears absorb light and that is how we can see the red or 'blood' within them, sometimes even veins. This is because our ears are absorbing the light and scattering it around our ear structure. However it is not as clear as that of a leaf and that is because our ears have different properties which allow less light to be absorbed.
For me, understanding the science of light is crucial for when I come to lighting my own environment next year. It is not so much knowing what different types of light exist, but how and why they occur, focusing on materials and specific objects that affect it. When I build my own Subway station, I will need to consider how my two variants Clean/Eroded will be portrayed specifically using lighting methods. Utilizing the materials and textures of a surface and how particular methods of lighting will alter the surrounding. Understand the mechanics of light and lighting is very important for me to portray the two different styles in the future.
No comments:
Post a Comment