Why is the shadow from a light the oppisite coluor of that light?

Answer 1

Here's why.

First, understand the concept of 'white point.' Look at your computer monitor (in the area to the left of the text). It looks white, correct? Now look at a piece of paper ... it also looks white. But now take the piece of paper and hold it up next to your monitor. (Ignore the brightness difference.) Now you see that your monitor looks bluish, or that the paper looks yellowish (the color of the light in the room).

In other words, your eye decides what is white by the predominant white field in your visual field.

Now, if you shine a yellow light on a white wall, you would think the wall looks yellow. However, if that is the *only* light shining on that wall, your eye adapts to that yellowness, making it the white point.

Now stand in front of that light, or hold an object up, so that you see a shadow on the wall. So now all the wall looks yellowish relative to the shadow, or you can say the shadow looks blue (the opposite of yellow) relative to the rest of the wall.

The same happens if you illuminate the wall with reddish light ... shadows look greenish relative to the reddish surroundings.

Answer 2

You are quite right, a shadow does not necessarily appear black. The best example I have ever seen was snowy street lit by orange sodium light. The shadows were all an intense blue - they did not look dark at all.

The reason has to do with the way colour perception works. You will have been taught that we see "red, green and blue" light and the amount of these gives us the colour. Almost every aspect of this statement is wrong.

Firstly, the colour receptors in the eye are sensitive to light in three different ranges of wavelengths, but these do not coincide with red, green and blue. But more importantly, it is blisndingly obvious that we do no see a particular colour because of the intensity of red, green and blue light coming from it.

How can I know this, you say. Well, a light bulb gives out around 90% of its energy at the red end of the spectrum. So in a room with the lights on at night a piece of paper looks deep red, right? Wrong!

And energy from the sun peaks in the green. So the same paper on a bright day looks slightly green, right? Wrong.

The brain is actually very sophisticated in the way it works out what colour something is, and does a very good job of achieving colour constancy effectively by comparing areas of a visual field.

But what this leads to is the fact that the brain does not simply "see" an absence of light as black. If there is no good foreground reference to establish what "white" is then it see the colour negative of the foreground.

Its a good job it works this way, or our sense of vision would be next to useless. Can you imagine the colour of everything changing in every direction you looked as the light conditions changed. Even a cloud going overhead would change the colour of everything.

Answer 3

Its tied to the way color breaks up in a spectrum.
White is a mixture of all the colors and when light passes through a prism, a rainbow is reflected.
I am assuming that the shadow is part of the prism of light therfore the shadow has the opposite part of the light in the object..so the shadow would throw a opposite prismatic color.
Artists such as Mattisse used outlining in the opposite spectrum color to the object and that created a different type of shadow..

I am looking at it through the eyes of the artist...hope this helps...

Answer 4

Because the absence of light is darkness .. and darkness is black ... by the way ... if you tried a red color ... it's shadow won't be the opposite :D

Answer 5

I matched printing ink colors it was necessary standardize the room with grey walls and 5000deg kelvin degree light to avoided off color matches.

Answer 6

It is not, a shadow is just the absence of light,

Answer 7

You are right but it is too complicated to describe here. Try looking on the net for UMBRA and PENUMBRA and this will explain everything.

Jules. lecturer. Australia.

Answer 8

when we see shadow of building becouse all colour of lights block in here. so thats why we see black place in here.

Answer 9

there're no opposite 'colors'.......