"Sighting" is a means of measuring and estimating using your pencil, a thumb, an index card--anything you can hold up at arm's length and "measure" with. You must extend your arm fully when sighting so that the pencil will always appear to be the same size in your field of vision. Then you can use your pencil to compare height to width, as in the illustration of the doors above, or you can compare the size of any two objects. Call the pencil length a unit of one. If the doors are one unit high, then we can estimate that they are almost two units wide. One cannot transfer the sighting measurements directly to the paper. That would mean letting the length of the pencil dictate the size of the drawing. Sighting will give you a means of estimating more accurately than you can by just looking. If something appears to be twice as wide as it is high, draw it twice as wide as it is high in your drawing.
One can also use a pencil or a straight edge to estimate angles more accurately but holding the pencil up as a horizontal or vertical reference as in the lower, left corner of the illustration above. Estimating angles accurately becomes very important when using two-point perspective as the vanishing points are often too far off the paper to be useful.
No comments:
Post a Comment