[Tron]

high @ all *g*,

i�ve got an interessting problem:
my question is whats the color of shadow, when the light ist red or blue or yellow?

is it the negative color? for example if the light is red, then the shadow is green?

or ist it just the color but with a cold temperature? for example when the light is orange-red then the shadow is red-blue?

or do you have any other ideas?


thanx for your replies.


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potatoes rule the world, follow them or prepare to die!

[ May 23, 2001: Message edited by: Tron ]

[waylon]

Hi. If you look at real life, the color of the shadow is whatever color the light is that's falling on it. If you have a bright yellow sun on a clear day, the shadow will be blue, because it's primarily getting light from the sky (which is blue.) This is the most important thing to think about when figuring out your shadow color - what is the color of the light that's actually reaching it?

Now, the other way to look at it, is I think what you're getting at. A shadow will APPEAR to be the complementary color of the light source - so a red light will appear to cast green shadows, a blue light will appear to cast orange, etc. The reason for this is that your eye is so used to seeing the color of the light, the shadow looks like the complimentary color by comparison.

You can use this to your advantage in your art, and make shadows seem deeper by pushing them towards the complimentary color... but keep in mind when you're doing it that the shadow, in real life, wouldn't actually BE that color, it would just SEEM to be that color.

[Sumaleth]

(Moved to Discussion)

[Impaler]

Keep in mind that all shadows would be pitch black were it not for the light reflections. Keep in mind what color light is being reflected, keep in mind what color it's being reflected off of (a blue light on a red wall is sort of purple-ish), and keep in mind what's underneath the shadow. (the desk under your pencil's shadow still shows through)

[Frost]

quote:

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Originally posted by Kaiju:
What waylon said is pretty much on the money. Basically, warm lights cast cool shadows. Cool light cast warm shadows. As far as the complimentary colors.. it is all very very subtle. So, don't go to extremes with it.

---

That is correct, artistically speaking, but holds false in reality (sorry Kaiju). As Waylon said, it SEEMS to be, but it isn't. If you have only one light source in an entire scene, the shadow will be of that color, just darker.

As a PURIST example, if you have a room with a red and blue light, the surfaces lit by both lights will be magenta, the surface lit by red but shadowed from blue will be red, the surface lit by blue but shadowed from red will be blue, and the surface that is shadowed from both lights will be black. But note that all sirfaces take in bounce light and reflections from surrounding lit surfaces, so you never get "pure" colors, only different levels of mixtures.

[Kaiju]

What waylon said is pretty much on the money. Basically, warm lights cast cool shadows. Cool light cast warm shadows. As far as the complimentary colors.. it is all very very subtle. So, don't go to extremes with it.

[Tron]

thanx a lot everybody,

i think its not easy to watch the colors and paint them at one time, because this causes a change of the papers color ( the colored light makes me see the painted colors and the paper�s color in a wrong way ).

so i tried to make a photo of the scenarios with changing light-situations.
damn, when a got those photos i couldn�t see the complementary colors in the shadows. but saw them when shooting the photos. well, are these (optical)colors only watchable by humans? i think so, because as you said they are not comlementary, but seem to be.
i�ll keep on trying!

[waylon]

Hi. When you think about it, it makes sense that the complimentary colors only showed up when you were there, but aren't visible in the photos. It's not that there's some different wavelength of light that's coming off the shadows that humans can see but cameras can't... it's just that your eyes are adjusted to the colored light, and so the shadows seem to be the complimentary color by comparison. The camera's shutter, on the other hand, just snaps open for a fraction of a second, so it doesn't have a chance to get accustomed to the light. It just records what's there.

Let me put this another way. When you were there, everything you were seeing was being hit by the light, and so your eyes adjusted. It's like when you close your eyes and stare towards the sun for a while, all you're seeing is red through your eyelids... Then when you open your eyes and look around, everything looks blue-green by comparison. (Try it!) If you're standing under an orange streetlight at night, almost everything you're seeing is orange. But your shadow is picking up whatever ambient light there is from your surroundings, so it'll look a lot bluer by comparison, because your eyes have adjusted towards the orange light.

When you're looking at your photos, your eyes are adjusted to whatever light is in the room, which is probably much whiter than whatever the scene lighting was. And so the shadows don't look so much like the complimentary color, because your eyes aren't desensitized to the color of the light.

Ack. I didn't describe that the best, I guess. But I'm tired, and should go home. Hope I've given you some help.

Oh yeah, and as far as the paper color being wrong when you're painting in colored light... well, you call always bring a little book-light or something that won't have much effect on the scene, but that will give you closer to a white light to paint by.

[William H. Daniels]

A good example of warm ambient lighting is pictures of Mars. The sky on Mars is redish, not blue like ours. Even with yellow-white direct lighting, the shadows take on a red cast.

There's also the difference between form shadows and cast shadows to take into account. The dark side of a red sphere will still be red, because the color of the object will affect the shadow color. The shadow that is cast by the red sphere, however, may have a bluish cast, depending on the ambient light color.

Also, a form backlit by a colored light will take on the color of the light. Stand facing the sunset and look at the dark sides of objects. They all have a redish-orange look because of spillover light from the sunset.

I think the most important thing to remember is that coloring in cast shadows is /very/ subtle. If you look at a form in ambient blue light with white or yellow-white direct lighting, the shadows will not be a garish blue. They will simply have a bluish appearance. The ambient lit surfaces pick up a fraction of the original color.

[Kaiju]

quote:

---

Originally posted by Frost:
That is correct, artistically speaking, but holds false in reality (sorry Kaiju). As Waylon said, it SEEMS to be, but it isn't. If you have only one light source in an entire scene, the shadow will be of that color, just darker.

As a PURIST example, if you have a room with a red and blue light, the surfaces lit by both lights will be magenta, the surface lit by red but shadowed from blue will be red, the surface lit by blue but shadowed from red will be blue, and the surface that is shadowed from both lights will be black. But note that all sirfaces take in bounce light and reflections from surrounding lit surfaces, so you never get "pure" colors, only different levels of mixtures.

---

I thought we were talking artistically. However, I'm thinking of what colors to combine to make the shadows. If it is a warm light then you will combine the surface color with a dark cool color and versa vice. At least that is how I believe it is to work in art. I agree with the PUREST example. Keep in mind (hehe..impaler) art is an illusion of reality and this is an example of one of those illusions. Then again artistically speaking it is all up to interpretation.

[BlackPool]

Hmmm..maybe I just got defuct eyes or something because I don't ever see complementery colors in shadows or any other color there that isn't there due to a strong ambient color. Shadows from my observation are more diffused areas of either the general light color if that color is other then whittish or if whittish, then it's based off the local color of the object. Ofcourse this is oversimplified I know.

[dogfood]

Strictly from my own observation: just prior to sunset a few days ago, the orange sunlight was cascading through the spindles of the deck railing, casting light blue shadows on my wife's thigh. There was no other blue around, save the darkening sky (mostly orange and gray). It was very illuminating. The next day, around noon, the harsh sun was beating down on my mailbox, casting a shadow that was merely a darker color of the sidewalk and roadway. Once again, very illuminating, though a little less exciting somehow.