|DRAWING SKETCHING COURSE: Light and Shadow|
This is an online drawing course free of charge.
„Light and shade“ is an own chapter, and there are good reasons to arrange it behind “difficulties”.
Shades on objects are not easy to see. Without light we wouldn’t see anything. In the retina are two types of light-sensitive receptors, the rod and cone cells. One type is used for "bright - darkness" seeing, the other is used for the perception of colors. The “bright-dark” cells are more sensitive than the other ones, therefore we can see quite good in weak light but have difficulties to recognize colours. “During the night all cats are grey” is a German saying, meaning that a difference is not important in this moment or situation. This saying refers to the phenomenon of the more sensitive “bright-dark” cells - you can see the cat but you can’t tell the colour.
So it should be easy, to see differences in the brightness of objects, but it’s not. Shades are difficult to discern. All our “seeing-process” is optimised to give us a good and solid orientation in a quick changing environment. Shades often are only disturbing without giving relevant information.
To give an example, in “every days life perception” it is much more important to recognize the face of Franz than to notice, that the right side of his face is shaded. Shadows are helping to model surfaces (the more deeply lying parts of a surface are darker and an special structure of the contrasts gives information about the material), on the other hand shadows are disturbing or even preventing the perception of forms and objects. Therefore we have a tendency to ignore shades when ever they don’t transport special information.
Unconsciously we lighten up the shaded parts and we equalize the brightness of the whole of object. Because of these corrections we “see” the right side of Franzen’s face as bright as the left, without even knowing, that they are lightened in a different way. Only if our interest changes from the question “who is this” to e.g. “at what time was the photo of Franz taken” we notice the shading as a source of information.
To perceive shadows you can use the “trick” to close your eyes nearly. You will see the motive through a tiny gap, it seems to be dark and blurred. The quantity of light breaking in the eye is so small, that the dark parts of the motive vanish and you can only see the brighter areas. In this way the contrasts are becoming stronger and you will see shadings, which where not perceptible before.
A technical trick, based on the same effect of reducing the quantity of light and rising the contrasts this way is looking at a motive through a “black mirror”. A black mirror is a plate of glass with a blackened back side. In former times the back side was blackened with the soot of a candle, today you would use black varnish.
“Black mirrors” also occur "naturally". When being inside a lightened room and outside it is dark, you can watch i.e. yourself or the room in the glass of the windows. The windows are “black mirrors”, reflecting less light than a normal (silver) one. Therefore the contrasts are strengthened and it becomes easier to perceive the shadings of the reflected objects.
The photo was taken during the day in front of the window of a shopping mall. As the room was lightened the ceiling of it is still visible through the window. On the photo it seems to be a kind of background of the reflection.
The photo isn’t optimal, but nevertheless the contrast in the reflected face are stronger than in the original one. Iit is easier to see the shadings in the reflected one. The effect is much stronger if the back side of the “black mirror” is really black and the motive is lightened brightly.