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Author Topic: Shadows  (Read 965 times)

artistforsaleorrent

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on: March 03, 2015, 08:33:44 AM
Shadows and Light

A shadow, in theory, is the absence of light, but in reality, there is light in shadow as well. Elementary science students are taught early that light always travels in a straight line from it’s source, called a light ray, be it the sun or a light bulb. What an artist must recognize is that shadows receive their light indirectly, as the rays from the primary source (the sun or bulb) ricochet off surfaces and bounce behind objects that block the direct rays, or more often than not, come in from a secondary, somewhat weaker light source which is either less intense or farther away from the primary source. The exception obviously being the sun as the primary because no matter how far away the sun is, something like 93 million miles, artificial light pales in comparison. Once passing by the object being illuminated, rays of light will bounce off objects near and behind that object sort of like how billiard balls will bounce off a cushion. If this did not occur, all shadows would be necessarily be total black. Even on the moon, I’m told, there are shadows although they are extremely hard to distinguish as being less than total black, the reason being that the moon’s surface isn’t that reflective as, say, a white wall.

For me, the most important aspect of any drawing or painting, again, THE MOST IMPORTANT aspect, is to determine the light source and it’s direction. Is it in front of the object casting the shadow, behind it, off to the right side, slightly above and to the left of the object? No matter where it comes from, it must be indicated first before I draw my first line in pencil. Often, I’ll very lightly draw a circle, easily erasable, to remind me at all times where my light is coming from. When using a photograph as the source of my composition, I still draw that circle even though the shadows are plain to see in the photo. It’s just something I do.

There are “cast”, “body” shadows, and “middle-tone” shadows, which also are on the actual object. Cast shadows are the shadows cast on objects or surfaces other than those that are actually blocking the direct light, and body shadows are the shadows actually on those objects that are in the light, on the surfaces where the light cannot reach, the dark side. Middle-tone shadows are the areas on the lighted side that are far enough away from the angle of incidence of the primary source’s light rays, which to our eyes appears that the color of the object is least altered by the light. For the purposes of this discussion, it really isn’t necessary to think of them as three separate things. I just want you to be aware that shadows are not simply one thing or another, or that they are painted or drawn the same way in every instance.

Now, getting back to actual shadows, all are darkest in the zone just beyond the features (often referred to as the “planes” a geometric term) illuminated by the primary light source. This is the shadow accent or the “core” shadow of the body shadow. This is where the light rays cannot reach, and where some of the secondary light source’s ray are blocked from that area. Less light means more dark. Think of it this way. It’s raining outside, you are under your umbrella, which rests on your shoulder at an angle. Your head stays dry because it is closest to the umbrella, Your midsection may get a bit wet, and for sure your shoes will get very wet. If you substitute dry for darkest, and very wet for lightest, you can see my point in reference to shadow accent or core shadow (the terms are interchangeable).

Confused? Am I giving you too much technical jargon?
How about this:




You’ll notice I used light blue to depict the light rays which will help in constructing the actual cast shadow. I do this religiously, based on years of experience learning to draw from a mother who was an architect and because it makes it so much easier to draw or paint a shadow accurately. You should try it. First, decide upon the direction of your light source and draw a small circle or something to indicate it. Secondly, take out a ruler or straight edge, and draw a simple solid rectangle somewhere. Thirdly, use that ruler, and lightly draw straight lines from the light source well past as many points of the surface of that rectangle as you need to outline the cast shadow and it will be obvious to you what the shape of the cast shadow should be. Core shadows and middle-tones are constructed similarly, but I figure it’s important for you to first be able to develop the cast shadow, and to get confident that your shadows look realistic.


Never be afraid to fail, because after all, "fail" actually stands for "the first attempt in learning". Robert


Happychappy

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Reply #1 on: March 03, 2015, 11:27:15 AM
Wow! Thanks for sharing your knowledge which I know we will all appreciate. Loved your diagram too and  :welcome:  to the Paint Basket family.     




Patricia
Patricia
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jillh

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Reply #2 on: March 03, 2015, 08:21:01 PM
Very interesting!  Thank you very much for sharing your knowledge with us.  I too welcome you to PB.
Jill
"What is easy to do is also easy not to do.  That's the difference between success and failure, between daydreams and ambitions"


artistforsaleorrent

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Reply #3 on: March 04, 2015, 04:30:38 AM
While I wanted you to first understand the makeup of a shadow in broad terms, a friend reminded me that the actual construction of a specific shadow varies depending upon the angle of the light source and of course the horizon and vanishing points of your painting's composition.

Again, I really don't want to get too technical, forcing the member to dust off your old solid geometry book. However, for those inclined to be accurate in all shadow respects, I urge you to try to read this treatise:  http://www.handprint.com/HP/WCL/perspect6.html  which is one of the most accurate and detailed instruction I have found to date. And while you might be overwhelmed by terms like "(1) the shadow vanishing point svp and (2) the light vanishing point lvp. Both points lie in the light plane vanishing line (lpvl)." or "The surface plane is horizontal; the spvl is the horizon line. The vertical shadow vanishing point (svp vertical) is at the intersection of the horizon line with a vertical line through lvp."

Yet, to be totally frank, had I not learned these terms as a youngster, and that through years uncounted I constructed my shadows geometrically, I undoubtedly would be challenged to have the patience or to actually remember them while approaching my seventieth year. But, that said, the article has enough visual aids to get each and every point across, and I highly recommend this article as a starting point for those of you who have trouble creating shadows, even while painting or drawing portraits, landscapes and especially a still life.

Let me know what you think.
Never be afraid to fail, because after all, "fail" actually stands for "the first attempt in learning". Robert


mea hamo pena

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Reply #4 on: March 04, 2015, 08:06:40 AM
Thank you, artist...

Wow, you have a wealth of experience.  I will study the shadow information you sent as shadows are one of my weaknesses.

aloha

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nolan

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Reply #5 on: March 04, 2015, 01:18:49 PM
very interesting and some great info,  :thankyou:


cyril

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Reply #6 on: April 20, 2015, 09:21:33 PM
thank you for this  info... i have book marked this info.


 

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