Measuring Proportions and Angles

Your eyes are easily fooled about size and angle. Measuring gives you a reliable way to check proportions while drawing from observation. These techniques have been used by artists for centuries, and they only require your pencil and your arm.

The pencil method (sight measuring)

1. Stretch your arm fully and lock your elbow. The distance between your eye and the pencil must stay the same for every measurement, or comparisons won't work.
2. Close one eye. With two eyes open you see two slightly different images.
3. Align the pencil tip with one end of the part you want to measure and slide your thumb to the other end.
4. Compare that length with other parts of the subject. For example: "the bottle is 3 times as tall as its neck is wide."

You choose one unit of measure (like the height of a head or the width of a cup) and express everything else in that unit.

Measuring angles

Hold the pencil at arm's length, vertical or horizontal (like a plumb line or a level). Compare the angle of an edge in your subject with the pencil. Is it tilted 20° from vertical? 45°? Then transfer that angle to your paper, comparing it with the edges of the page.

You can also "freeze" an angle by tilting the pencil to match an edge, then bringing it down to your paper, keeping the same angle.

Plumb lines and alignments

Imagine vertical and horizontal lines through key points of your subject. What lines up with what? In a portrait, the corner of the eye might line up vertically with the edge of the nostril. In a still life, the top of the cup might align horizontally with the middle of the bottle. These alignments are powerful checks.

Sight-size

In the sight-size method, you place your drawing next to your subject and step back until both look the same size. You then compare them side by side, from the same spot, and correct the drawing until it matches. It's very accurate and is still taught in classical ateliers.

The grid method

To transfer a photo accurately, draw a grid over the photo and a matching grid on your paper. Then copy one cell at a time. It's a great way to study a complex image and to enlarge drawings. The Reference Studio can overlay a grid on any photo: