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jfrancis
05-21-2009, 06:36 AM
http://www.digitalartform.com/assets/depth-of-light.jpg

Depth of Light
(http://www.digitalartform.com/archives/2009/05/depth_of_light.html)
If the light has falloff, especially inverse square falloff (http://www.digitalartform.com/archives/2009/05/violations_of_t.html), then close lights look richer and less flat than distant ones.

phix314
05-21-2009, 08:32 AM
....?

And?

mister3d
05-21-2009, 03:55 PM
This is called "light perspective", and shows that the farther away the light source, the less difference in illumination of different parts, in this case the man and the wall.

jfrancis
05-21-2009, 05:21 PM
This is called "light perspective", and shows that the farther away the light source, the less difference in illumination of different parts, in this case the man and the wall.

Light Perspective is probably a better term for it. I always heard it called Depth of Light. I'm surprised neither term turns up much on Google.

jfrancis
05-21-2009, 05:22 PM
....?

And?

Lots of photographers emphasize richness and falloff by bringing the lights in as close as they can without seeing them in frame.

Lots of Maya lighters I've seen put the lights far away, don't give much thought to distance, only direction, and even disable falloff entirely.

mister3d
05-21-2009, 06:43 PM
Light Perspective is probably a better term for it. I always heard it called Depth of Light. I'm surprised neither term turns up much on Google.

It's about the inverse-square falloff, if to be more scientific. We can invent any amount of ridiculous and confusing names, like "the blessing of Light Distance" or "Kingly falloff". Well who cares, the main thing you understand how light behaves and how to use it.

jfrancis
05-21-2009, 08:58 PM
http://www.digitalartform.com/assets/Inverse-Square-Law.jpg

It's about the inverse-square falloff, if to be more scientific. We can invent any amount of ridiculous and confusing names, like "the blessing of Light Distance" or "Kingly falloff". Well who cares, the main thing you understand how light behaves and how to use it.

Actually it's not a behavior of light. It's a behavior of things expanding in a spherical manner.

Violations of the Inverse Square Law (http://www.digitalartform.com/archives/2009/05/violations_of_t.html)

mister3d
05-21-2009, 10:42 PM
"Things" include light, just those things include many other things. But you are right, it's good to look at this from a more universal outlook.

RagingBull
05-21-2009, 10:44 PM
....?

And?


Tis a bit rude man, it's definitely useful for beginners and a reminder for oldies too :)

mister3d
05-21-2009, 10:51 PM
Tis a bit rude man, it's definitely useful for beginners and a reminder for oldies too :)

Where is it rude? Not at all, just he asked for some explanations. Can you really explain now how to use this in working with lighting? Just one example?

jfrancis
05-21-2009, 11:48 PM
"Things" include light, just those things include many other things. But you are right, it's good to look at this from a more universal outlook.

My point is that if light does not expand spherically then it will not fall off as the inverse square of the distance it travels. Light does not inherently fall off according to the inverse square law.

mister3d
05-22-2009, 12:02 AM
My point is that if light does not expand spherically then it will not fall off as the inverse square of the distance it travels. Light does not inherently fall off according to the inverse square law.

Hmmm... actually yeah... light itself does not decrease in its intensity, it just becomes less dense. From another point, we still can say that it's light behaviour, as it decreases its density according to the sperical distribution concept. Isn't it?

jfrancis
05-22-2009, 12:25 AM
It is light's behavior as long as it is not reflected from the focus of a parabolic mirror, or shined through a collimating lens, or measured near a large softbox, or a long glowing tube, or the inside surface of a sphere, or organized into a laser beam, or internally reflected down the walls of a fiber optic cable, or...

Carina
06-05-2009, 11:02 AM
It is light's behavior as long as it is not reflected from the focus of a parabolic mirror, or shined through a collimating lens, or measured near a large softbox, or a long glowing tube, or the inside surface of a sphere, or organized into a laser beam, or internally reflected down the walls of a fiber optic cable, or...

Technically the behaviour of light doesn't change in these circumstances, it's the environment that changes. :)

phix314
06-05-2009, 10:01 PM
Tis a bit rude man, it's definitely useful for beginners and a reminder for oldies too :)

Sorry mate, I just didn't understand it's standalone nature ;) usually theres something accompanying it, like a question or declaration of knowledge.

earwax69
06-09-2009, 01:39 PM
Thanks... Im one of those who usualy left their lights on "no falloff". I've just learned something thanks a lot! Though I have to say for my defence I am not a texturer or lighter and tend to use Global Illumination anyway.

Your post is very welcome!

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