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The Dynamics of Photographic Lighting
Interesting view on shadows
Mar 27, 2022 21:49:54   #
Steve DeMott Loc: St. Louis, Missouri (Oakville area)
 
During some research on portrait lighting I found a interesting article about shadows.

"A light source doesn't create a shadow!
Light sources create light!

When you commonly say that light hits an object and casts a shadow, you have to understand that light doesn't reach the area behind the opaque object - the area we call the shadow.

The brightness behind the object remains the same if you switch off the lamp in front of it. Seeing a shadow is just a question of contrast.

If you want to build a world without any shadows, then you have two solutions:

Switch off all light sources.
Switch on many light sources everywhere!"

The question is: If there isn't light in front of a solid object, is there a shadow behind the object?

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Mar 27, 2022 21:57:25   #
srt101fan
 
Steve DeMott wrote:
During some research on portrait lighting I found a interesting article about shadows.

"A light source doesn't create a shadow!
Light sources create light!

When you commonly say that light hits an object and casts a shadow, you have to understand that light doesn't reach the area behind the opaque object - the area we call the shadow.

The brightness behind the object remains the same if you switch off the lamp in front of it. Seeing a shadow is just a question of contrast.

If you want to build a world without any shadows, then you have two solutions:

Switch off all light sources.
Switch on many light sources everywhere!"

The question is: If there isn't light in front of a solid object, is there a shadow behind the object?
During some research on portrait lighting I found ... (show quote)


Interesting! Your question sounds like a Zen koan....

(Can't wait to see Ed Shapiro's comment!)

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Mar 28, 2022 22:02:49   #
E.L.. Shapiro Loc: Ottawa, Ontario Canada
 
Whoever wrote that theory is probably not talking about the DYNAMICS of light but the SEMANTICS of light or whatever. My theory is too simple and it is not of my invention or discovery. "Where there is light there is shadow". I can ad "it all depends on where you are standing so you can see it"

In nature, at least here on earth, we only have one SUN so the light on a sunny day only comes in one direction at a time. I suppose that's how we are used to seeing things. On a cloudy overcast, the sunlight is diffused but we only have one sky.

You can create a SHADOWLESS image if the light is a ZERO degree to the lens or kida lighting comes out of ring light or if you overly fill in directional lighting so the shadows are overpowered but that is more of a special effect. If you somehow moved the ring light vertical, even just a few inches above the lens, in a portrait a small SHADOW would form under the chin and nose- it's called vertical modelling.

Under normal circumstances, if the light strikes any subject from an off-camer axes position, whatever gets in the way of that beam of lig, a tree, building, mountain, fire hydrant, cat, or a protuberance, like a nose on someone's face, is gonna cast shows.

Problem was, back in my school days, I was too busy studying stuff like optics, darkroom chemistry, lighting, etc., but I sort of neglected English so I don't know if the beam of light CASTS the shadow or whatever gets in its way. All I know for sure is the shadows are always there and it ain't too hard to find them. The trick is to get them in the rigt place on the face!

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Apr 1, 2022 06:33:19   #
Rongnongno Loc: FL
 
 


(Download)

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May 1, 2022 05:15:45   #
R.G. Loc: Scotland
 
Steve DeMott wrote:
.....light doesn't reach the area behind the opaque object - the area we call the shadow....


This just seems like a meaningless and not very inspiring play on words. The situation where you have no light reaching the shadow area will occur only if there is absolutely no ambient light - a situation that is going to arise very rarely (unless you're in outer space or on the moon).
He also wrote:
Seeing a shadow is just a question of contrast.

It's the light - and the lack of that light - which gives you that contrast. No light, no contrast. To be more specific (which is more than the person giving us these quotes can claim), it's directional light which gives us shadows. With omnidirectional (i.e. ambient) light, there is no back and front.
He also wrote:
If there isn't light in front of a solid object, is there a shadow behind the object?

For a start, if there isn't any light in front of an opaque object, you won't see that object. And depending on how you choose to define "shadow", in that situation it's either all shadow or no shadow.

So what's the big take-away from this? Light can be either directional or omnidirectional and it's directional light which gives us the contrast that we refer to as "shadow".

I get the impression that there probably is an inspiring idea behind the quotes, but the quotes on their own don't reveal what the inspiring idea is. Perhaps if the OP described what his take on the subject is it might point to some useful ideas.

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May 1, 2022 08:06:54   #
R.G. Loc: Scotland
 
R.G. wrote:
....To be more specific (which is more than the person giving us these quotes can claim)....


I realise this comment is a bit ambiguous. I'm referring to the person that wrote the original article, not the person that posted this thread (who I know and respect as a fellow UHHer). If that article is supposed to point us to a more enlightened way of thinking about shadows, it's missing the mark - at least with me.

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