The orange cube exercise

Summary

This video script introduces an exercise using an orange-painted cardboard cube to explore three types of color perception: object colors, illumination colors, and colors reaching our eyes. It challenges viewers to consider whether they perceive the cube's faces as differently colored due to light or as uniformly colored under varying illumination. The script delves into how our visual system interprets these colors, the concept of color constancy, and the impact of simultaneous contrast. It also touches on how artists might view scenes as arrays of light to translate into paint colors, suggesting the use of a cardboard mask to isolate light perception. The exercise serves as an introduction to a course on color, focusing on object and illumination colors, their attributes, and their significance in various fields.

Takeaways

• 🎨 The script introduces an exercise using an orange-painted cardboard cube to explore three types of color perception: object colors, illumination colors, and colors of light reaching our eyes.
• 🔍 The perceived color of an object changes based on the amount of light it receives, but we tend to perceive the object's color as uniform despite varying illumination.
• 👀 Our visual system interprets colors not just as light and dark but as objects of certain colors under specific illumination, such as 'white' light.
• 📐 The exercise challenges us to consider whether we see different colors on the cube's faces or the same color under varying light intensities.
• 🖼️ The script suggests that we perceive a uniform color through different intensities of light, akin to perceiving uniform, white, and black objects under varying illumination.
• 🌈 The colors we perceive as belonging to objects are referred to as 'object colors,' while those perceived as part of the illumination are called 'illumination colors'.
• 🗿 The script encourages observing other uniformly colored objects, like a statue, to understand if we perceive them as having different colors or as the same color under different light conditions.
• 🌟 Object color perception remains relatively constant across various viewing conditions, leading us to perceive it as an inherent property of the object.
• ⚖️ The constancy of object colors is not perfect, as demonstrated by the phenomenon of simultaneous contrast, where neighboring colors influence our perception.
• 🎨 Painters may choose to see a scene as a flat array of light patches of varying intensity and color, translating these into paint colors.
• 🖌️ The script recommends using a cardboard mask with a small hole to help see the light from different areas of the cube, divorced from the context of the cube as a whole.

Q & A

What is the main purpose of the exercise with the orange cardboard cube?

The main purpose of the exercise with the orange cardboard cube is to introduce the concept of three important kinds of colors: colors perceived as belonging to objects themselves, colors of the light falling on objects, and colors of the light reaching our eyes from objects.

How does the appearance of the cardboard cube's faces change, and what does this demonstrate?

The appearance of the cardboard cube's faces changes depending on the amount of light they receive. This demonstrates the difference between object colors, which are perceived as belonging to the objects themselves, and illumination colors, which are perceived as varying intensities of light.

What is the significance of perceiving the cube as having similarly colored faces illuminated by different amounts of light?

Perceiving the cube as having similarly colored faces illuminated by different amounts of light is significant because it shows our visual system's ability to perceive object colors consistently, even under varying illumination conditions.

What are the two patterns that we perceive superimposed on the same rectangle according to the script?

The two patterns perceived superimposed on the same rectangle are the pattern of uniformly colored objects (uniform orange, white, and black) and a pattern of light and shade, which is a pattern of illumination of varying intensity.

How does our visual system perceive an object of a certain color under illumination?

Our visual system perceives an object of a certain color under illumination by automatically presenting us with a perception of an object with a fixed, inherent property of color, illuminated by a certain color of light, typically 'white' light.

What is meant by 'object colors' and 'illumination colors' in standard scientific terminology?

In standard scientific terminology, 'object colors' refer to the colors perceived as belonging to objects themselves, and 'illumination colors' refer to the colors perceived as belonging to the light source illuminating the objects.

How does the perception of object color remain relatively constant through wide variations of viewing conditions?

The perception of object color remains relatively constant through wide variations of viewing conditions because our visual system perceives the object's intrinsic capacity to reflect various wavelengths of light, which is perceived as a seemingly fixed property of the object.

What is 'simultaneous contrast' and how does it affect the color perception of objects?

Simultaneous contrast is a phenomenon where the colors of neighboring areas impact the color we perceive an object as having. It demonstrates that our perception of object color is not entirely constant and can be influenced by the colors around it.

How can painters view a scene differently from the way we normally perceive objects and illumination?

Painters can view a scene as a flat array of patches of light of varying intensity and color, translating these colors of light reaching their eyes into colors of their paints, which is a different approach from the usual perception of objects and illumination.

What technique is suggested to help see the areas of the cube as light rather than as part of the whole cube?

The technique suggested to help see the areas of the cube as light is to look at them through a small hole in a piece of cardboard, which isolates the light from different areas of the cube from the context of the cube as a whole.

What is the ISCC/AIC Colour Literacy Project mentioned in the script, and what is its goal?

The ISCC/AIC Colour Literacy Project is an international initiative aimed at providing state-of-the-art educational resources that strengthen the bridges between the sciences, arts, design, and humanities, with a focus on color education.