|DRAWING SKETCHING COURSE: drawing and sketching three dimensional objects|
This is an online drawing course free of charge.
When a draughtsmans draws “naturally” (in German we say „after nature“) he is making a two dimensional projection of a 3 dimensional object. That is difficult, not only for beginners.
For this reason Duerer e.g. designed a "projection machine" and many painters used optical aids such as lenses and hollow mirrors, the "Camera Obscura", the "Camera Lucida" (e.g. Ingres) or since 1850 the Photography, which was used by nearly all painters since then.
Most humans see three-dimensional. Exceptions are e.g. people being blind on one eye or persons being walleyed. Three-dimensional seeing is the result of a complex process, in which the brain analyses the different pictures being supplied by the eyes.
In addition empirical values are consulted like the knowledge about sizes of special objects in certain distances or the experience, that objects being covered by others are lying behind the covering ones.
Above all the eyes supply two different pictures of a viewed object, specially when it’s less than 10 meters away. The pictures of the eyes differ the more the object is closer.
Look at a cigarette box, being 20 centimetres in front of your nose, the small sides parallel to a plane through your face. You will see the front side of the box and both sides.
Now you close your eyes alternating. You’ll state, that you can see the front and the right side, when looking with the right eye, and that you can’t see the left side.When closing the right eye and looking with the left, it will be the other way round.
Now, what will you draw? A box with front , left and right side? Before the Renaissance that would have been ok, nobody would have been disturbed by a "wrong" picture.
Now you set up the box in two meters distance, you repeat the procedure, and you see that the effect is substantially weaker.
Therefore the tip: Hold distance to your motif, when drawing and sketching!
The (upper) right eye sees the front and the right side of the square, but nothing from the lower (left) side. The lower left eye however sees the lower left side and the front of the square. The observer sees altogether thus 3 sides of the box, completely against all "rules" of the perspective.