WEEK 2 - DAY 2 - Colour and Light

WEEK 2 - DAY 2 - Colour and Light

Light

Much of our knowledge about light derives from experiments that the scientist Sir Isaac Newton (1643–1727) carried out in the 17th century.

He demonstrated that daylight can be split into a series of colors. This sequence of colors—red, orange, yellow, green, blue, indigo, and violet—is known as the chromatic color sequence. Colors that are not part of this sequence, such as beige or burgundy, are known as nonchromatic colors.

CHROMATIC COLOUR SEQUENCE: ROYGBIV

Why Objects Appear  Colored

When we see an object lit by white light, its color is due to the object absorbing some colors and reflecting (or transmitting) others. For example, green foliage appears to be green because it contains pigments that absorb blue and red light and reflect only green light. It is a similar story when the light is viewed through an object, such as a photographic filter. You only see the part of the spectrum that is allowed through. For example, a blue filter blocks red and green light, and allows only the blue part of the spectrum through.

Measuring Colors

Human vision is very good at recognizing the differences between two colors seen side by side. However, it is a different story when it comes to accurately describing individual colors to someone else.

While our eyes cannot see ultraviolet or infrared radiation, these can have an effect on the image produced by both digital sensors and film. In most circumstances, it is undesirable for the image to register radiation outside of the visible spectrum.



The nature of light itself is still the subject of much speculation. Current theories explain light by giving it the properties of both waves and particles. We will deal primarily with the wave theory; this explains the aspects of light, such as wavelength and frequency, that concern us in color photography.

Light Waves

Light waves are the visible part of a much larger group of waves known as the electromagnetic spectrum, which includes X-rays and radio waves. The  range that is present in daylight is shown below. This ranges from the short-wavelength ultraviolet to the longer-wavelength infrared, with the visible portion in between.

ACTIVITY 1

STEP 1: Using the crystal and a light source take at least 3 images of the chromatic colour, i.e rainbow that you get when you sign a flashlight into the crystal.

STEP 2: Create a Google slide show titled WEEK 2 - Colour, and create your first slide with the image you took of the chroma colour light split and a description of the image. 

SUGGESTION: Access the you tube video using "mandelbrot set" as a search to show light images, you can take images of the screen as a substitution for the crystal images.