Dear Theo,

In my last letter you will have found a little sketch of that perspective frame I mentioned. I just came back from the blacksmith, who made iron points for the sticks and iron corners for the frame. It consists of two long stakes; the frame can be attached to them either way with strong wooden sticks.

So on the shore or in the meadows or in the fields one can look through it like a window. The vertical lines and the horizontal line of the frame and the diagonal lines and the intersection or else the division in squares, certainly give a few pointers which help one make a solid drawing and which indicate the main lines and proportion ... of why and how the perspective causes an apparent change of direction in the lines and change of size in the planes and in the whole mass. Long and continuous practice with it enables one to draw quick as lightning.

### From The Complete Letters of Vincent van Gogh

Perspective is a set of rules to explain how to draw objects in space and make adjustments for the difference between what the eye sees and the mind knows, or thinks it knows. For example, the mind knows that a cube has six equal sides, but when a cube is seen in space, the sides seen at an angle seem to diminish as they recede.

Perspective has always been a challenge to artists, and many, like van Gogh, made elaborate contraptions to help them see and draw things in space. Perspective can seem a challenge for you, too, but you can use it as a tool to help you improve your drawing.

In this chapter, we'll bring perspective into clear focus and simplify it so even an "idiot" can understand. In fact, there's nothing terribly complicated about perspective; it's just a matter of recording on the page what the eye is really seeing.