Palette shadow illusion (13th of November 2011)
Press play in the window above to start streaming from YouTube. The video I made for this post is an optical illusion. It illustrates the fact that the construction of "mental map" of a three-dimensional nature of the object requires many types of visual information that we are rarely aware of while we process the world around us. Here are some more important ones:
- Perspective; perspective "shortening" of the more distant parts of the object
- Illumination; the character of light on different parts of the object
- Shadows; where are the shadows and what is the nature of their geometry, what casts shadow and where?
The illusion in the video "functions" because
- the representation of the object is in orthographic and not perspective projection
- the object does not cast shadows (on itself)
- the light source is in a special position, and
- the object geometry / palette is special, i.e. it consists of spherical bulges / depressions in a plane.
Good drawings and good paintings will take to their advantage all the elements which we (mostly completely unconsciously) process in order to create a sort of "illusion" of a three-dimensional nature of the objects they represent. That is why a painter must understand well how the mind processes the visual, because the good painting is always a result of "cheating" the mechanisms which interpret the visual information. I am (still) an unskilled drawer (the one who draws) and my drawings are not the best illustration of this grand story, but anyhow, in this post I will illustrate this idea with my drawings of hands, feet, and one knee. Some of these drawings are more than a year old.
A good drawing must feature, besides correct geometry, a faithful representation of the relation between lighter and darker parts of the object / drawing. From this relation between the light and the shadow, our mind / brain judges about the three-dimensional nature of the (represented) object.
I have a tough time getting a smooth, continuous transitions between the tones of dark and light. The academics do it fantastically,
so that I avoid watching the works of good students of good academies because they can be demotivationally too good.
The smooth transitions are particularly effective since the generate an illusion of softness and they characterize the "roundness" of
a part of the object. Is this part of the object more like a cylinder or a sphere or is it some interesting combination of the
two geometries? What are its curvatures?
The subject of this post is a part of the story about painting in general. For its upgrade, I recommend the reading of the articles in Wikipedia about >> grisaille painting and about >> chiaroscuro "modeling" of light. Very instructional, and there you will also find examples of "modeling of light and shadow" which are much better than the ones I present here.
In the end, another hand in a strong perspective (below).
to an old dead tree
get word to April
to rescue me
Tom Waits, November
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Last updated on 13th of November 2011.