This is basically a photography lesson about light. Using Cycles you need to understand how work with concepts that work in real life film, and where cycles lacks in recreating real life light.
In this tutorial, I'll go over the basics of lighting a scene, emotions, and temperatures of light. I'll describe the proper way to light a scene and how to get the most from your images and animation to work with the emotion you want to create.
After the break, will be the video, and a lengthy few paragraphs about light and how it works...
This is not intended to teach you the details of using emitters and modeling, it's just how to work with lights in a scene and make a well lit scene, even dark scenes, with well lit subjects.
According to Wikipedia:
Visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has a wavelength in the range of about 380 nanometres to about 740 nm – between the invisible infrared, with longer wavelengths and the invisible ultraviolet, with shorter wavelengths.
Primary properties of visible light are intensity, propagation direction, frequency or wavelength spectrum, and polarisation, while its speed in a vacuum, 299,792,458 meters per second, is one of the fundamental constants of nature.
Visible light is emitted and absorbed in tiny "packets" called photons, and exhibits properties of both waves and particles
In cycles, light is attempted to be accurate by using Light Path Expressions. As defined here:
I won't go into the details, but understand that the way it works, is to trace a random spot on the screen (generated by the seed, and a randomizer) point it directly at the scene, and follow how many bounces it takes till it hits a light source. That ray is then multiplied with the other rays for that same pixel and generates a two dimensional image like a photograph.
To make it simple, it's reversing the path of photons of real light to generate the image.
The Major Differences
Cycles "reverse photons" don't carry anything more than a few parameters of light; Intensity, Direction, and Color (frequency). The wavelength, polarization, and speed do not exist to cycles.
Because of these missing parameters, we lose some things about real light; dispersion by refraction. Or, for example, how a prism creates a rainbow from a white light source.
We also lose information about falloff of light intensity by wavelength, thus red light will travel as far as blue light in a scene, producing less accurate lighting. Imagine a street scene, from a helicopter, at night you would barely make out green and yellow lights from stop lights, but red normally blankets these scenes. Red can travel farther than other colors, due to its wavelength and lack of dispersion through air. If you were to recreate this scene in cycles, with the same origin emitter intensities, you would see just as much green as you would red, which is inaccurate.
So when we create a scene, in cycles, we should verify with reference photos to assure accuracy of a scene, if we are trying to be accurate.
Of course, if your scene is to be purely fictional, then you make it as you like...
Physics behind us, let get into some concepts of lighting:
I assume you've seen the preface to this tutorial about professional lighting of an indoors scene. Taking note of the setup and surroundings. If you haven't, I highly recommend you check it out.
Here's what I'll be going over in the video:
- 3 Point Lighting
- Soft and Hard light
- Soft light, large, farther source
- Hard light, small, closer source
- Diffusion Bouncing
- Shadows and silhouettes
- Light Falloff (further from a light source the darker it gets)
- Textures and Direction; Front light removes depth, side light emphasizes depth.
- I forgot to mention this in the video. How sad! Just know that light can emphasize textures and bump maps, and make it look like it has more depth. BUT don't rely on light to do it all, your material may need to have some darkness.
- Colors can emphasize temperature.
- It can also emphasize emotion.
- Warning lights
- Emergency lights
- Peaceful and Holy
- Evil or Sinister
- Download the Modified Blend File
- The original from Blendswap.com is at the bottom of this page.
How to Light Your Scene
- What is your subject?
- What is the emotion/feelings you want to convey?
- What is your surroundings?
- What is the temperature you want to describe?
Here's the still renders shown in the video:
|3 Point Lighting Example
|Red Lighting (Emotion: Evil)
|Yellow Lighting (Emotion: Warning)
|Blue Light (Emotion: Natural)
|Red Light (Emotion: Disaster)
|Bright Lights (Emotion: Comforting)
|Bright Lights With Gloss Floor (Emotion: Clean, Pure)
|Bright Lights With Diffuse Floor (Emotion: Warm)
|Three Point Light - Natural
|Three Point Light - Dark
|Three Point Light - Warm
I used a blend file from blendswap.com in the video:
Thanks to mcavady for providing this scene to the community.