The Picture Plane
This is a very simple but very important concept. Imagine the Picture Plane as a sheet of glass between you and what you're drawing. It makes no difference how far away you imagine it is. Now close one eye and imagine everything you see is squashed flat onto the back of the glass, like a picture on a TV screen. This translates all the perspective and foreshortening you can see into flat two-dimensional shapes that can be copied onto your paper. This must be done with one eye closed because each eye will see these shapes in different positions. We'll come to perspective in a minute but, for now, just remember that the 'Horizon Line' runs across the picture plane at eye level, or to put it another way, your eye level is called the 'Horizon Line' – meaning you're looking down on anything below it and you're looking up at anything above it. It's important to imagine the picture plane in open space so that your drawing board does not 'puncture' it. They are not the same thing and should not be confused with each other. Nothing can occupy the same space as the picture plane, otherwise you would see a cross-section of the object in your drawing!
Once you can see everything on this imaginary 'surface' you do not need to think about perspective and foreshortening. All shapes on the picture plane are flat. It takes some practice to see foreseen objects as flat shapes (and it always helps to close one eye), but once it clicks you'll find drawing everything a lot easier.
A good way to get used to the concept of a picture plane in portrait drawing is to stand or sit in front of a mirror and draw yourself or anything else you can see, with a wax pencil (Stabilo make a nice range called 'Aquarellable' ), and with one eye closed, straight onto the mirror. Try to choose subjects that are turned at awkward angles and foreshortened. Another way of achieving the same effect is to stand inside a window and trace the objects outside straight onto the window pane, again making sure you keep one eye closed. This is supposedly what Hans Holbein (the famous portrait painter in the court of Henry Vlll) used to do before transferring his drawings onto paper. Yet another way of practicing this is to balance a sheet of glass on the outstretched fingers of one hand and to trace around it's contour with the other.
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