Exercise: Drawing with the Sight-Size Method

Ben Rathbone describes how to use the sight-size method to construct a realistic drawing of a cast. Here are the materials needed:

• Long ruler or T-square
• String
• Divider (can also use any long straight object like a pencil or brush)
• Plumb-line (can be created a by tying a large hex-nut to a piece of string) 
• Easel or table
• Drawing support
• Drawing materials (such as, pencil, pen, pastel, or paint)

Here are the basic steps:

1. Set-up the drawing reference (in this case a cast) and support (paper). The reference and the support need to be positioned at the viewer's eye level. Be sure that you have enough space on the paper to fit the reference as you see it. The support should be mounted as straight and perpendicular to the floor as possible. If desired, mount the plumb-line in front and in the middle of the reference.
2. Stand directly in front of the support to have a clear view of the reference. Take several steps back away from the reference and support. Position yourself so that you can clearly view the reference and support without moving your head. This is your "vantage point". From here that you will be able to look at the cast and drawing, and have both appear to be the same size.
3. Establish the initial reference lines to aid the basic construction of the drawing. To do this stand at the vantage point and fully extend both arms pulling the string into a straight horizontal line. Keeping the line horizontal, raise the string until it touches the very top of the reference image. Make a mental note of where the string intersects the edge of the support. Then mark this point on the support, close to the edge. Do this again and again to identify the location of key elements from the reference.
   
   



4. Take the ruler and place it horizontally on the support. Draw a horizontal line across the support through each mark. Then draw a single vertical line that corresponds to the plumb-line through the center of the reference.
5. Begin placing basic lines on the drawing to establish the big shapes associate with the reference.

Note: To take a specific measurement from the reference and move it to the drawing on the support, use the divider (or its replacement). To do this, fully extend the arm with the divider in hand and capture the measure (if using a a long straight object for this purpose place your thumb on the object to capture the length). Then with the arm still extended move the divider so it is visually over the support.

To view the complete exercise click here.