Row 1: The spectrum of the light source - to set this, push the mouse button and drag it across the graph (you may need to try this a few times). The response of the three cone types is represented in the bar graph to the right, and a small disk shows what color the light is.

Row 2: The reflectance spectrum of the object (how much of each incoming wavelength it reflects) - set this the same way you set the light source spectrum. The bar graph on the right shows what the response of the cones would be to that object if it was illuminated by white light, and the disk shows what the color of the object would be if it was illuminated by white light (but you may not have set the light source to be white light - an equal mixture of all wavelengths.)

Row 3. The resulting spectrum of light that hits your eyes after being reflected off of the object - The graph shows the resulting spectrum of reflected light, the bar graph shows the response of the three cone types, and the disk on the right shows what the color the object would be under the light from the source that you set.

Try setting the reflectance spectrum of the object (middle row), then change the spectrum of the light source (top row) to see the effect on the apparent color of the object (bottom row.)


TWO MATERIALS - This is organized in the same way as the RGB Insufficiency demonstration, except that there are two objects instead of just one. First Row: Light source, Second Row: Reflectance spectra of the two objects, Third Row: Light spectra that reach your eyes from the two objects, Fourth Row: Bar graphs showing the responses of the three cone types to the objects and disks representing the apparent colors of the objects.

Try making one object with mostly long wavelengths and the other with mostly short wavelengths. Now try making the light source white (an equal mixture of all wavelengths),then predominantly long wavelength, then predominantly short wavelength. Notice waht happens to the brightness and color of the two objects.


METAMERS - This demonstration works in essentially the same way as the other two demonstrations. The graphs represent the reflectance spectra of two different objects. To set the reflectances, push the mouse button and drag it across a graph (you may need to try this a few times.) The bar graphs below represent the responses of the three cone types, and the colored disks represent the apparent colors of the objects. This demonstration assumes a white-light source.

Try to create two different spectra that produce the same color of object.