Sight size/relative size

[Michele Rushworth]

I was taught, and in turn I teach my students, to draw using relative size. It's hard enough sometimes to set up the model, lighting and fifteen students in a studio without having to restrict everyone to working "sight size".

Working only sight size also limits the size of canvas you can use. Working with relative size means more math and ratios (yuck!) but gives you much more flexibility as to your position in terms of distance from the model and the size of your finished image.

For those of you not familiar with the term, "sight size" means you create the image on your canvas the same size as you see it. For example, you might use a pencil held at arms length for measuring. A feature on the model may appear to be as long as the eraser and ferrule of the pencil. You then make it as long as the ferrule and eraser on the canvas you are working on.

[Michael Georges]

Michele:

Can you give more details on relative sizing and how it works?

[Michele Rushworth]

Let me see if I can put it into words...

It's all about ratios. Whenever I start a drawing or painting from life I put little lines as "landmarks" on the canvas. If I'm doing a head and shoulders portrait, I would first decide how tall I want the head on the canvas. That has nothing to do with measuring the model but is purely based on the composition I want in the painting. It can be much larger or much smaller than the dimensions the model actually takes up in my field of view. (Painting the model the actual size he or she takes up in my field of view would be "sight-size" drawing.)

Now the measuring starts. I first want to know how wide the face is compared to the height I've established. I measure the height of the live model's head by holding my pencil at arm's length. I visually line up the top of the pencil at the top of the model's head and move my thumb down the pencil 'til it's at the bottom of the chin. (Close one eye when you do this -- it's much easier!)

Then I hold my pencil horizontally and compare the width of the face with the height I've measured, with my thumb still in the same spot on the pencil. Let's say I find that the width of the actual model's head is two-thirds of its height. That ratio of two-thirds is the key.

On my canvas I then measure a width dimension that is two thirds of the length of the height marks that I've established. (You can use a ruler or any stick that is a useful length.) If the vertical head dimension I want on the canvas is 12 inches tall, I'd mark the outer edges of the head width at 8 inches, which is two-thirds of 12.
(Hence the math.)

This measuring process repeats over and over 'til you're confident that you have all the landmarks you need to get the likeness. You can measure from the outside in (head dimensions first) or from the inside out (using one of the features of the face to compare everything else to, for example).

The better you get at drawing the more this measuring process becomes automatic and you don't need the pencil held at arm's length any more to do your measuring. At some point in your development you'll be able to just mentally note that the model's mouth is one-and-a-half times the width of the nose, for example.

Hope that helps!

[Steven Sweeney]

The sight-size method isn't quite that restrictive with respect to canvas size. I've worked in the life room of a studio with a dozen other artists, all working sight-size on large bulky easels, and found myself executing a 48" pastel figure study while the artist next to me worked on a 15" pencil drawing. We were both working sight-size. The difference was, in part, where we'd set up our easels (though they were actually in pretty much the same relative position from the model), but as significantly, where we each stood in relation to the easel when we took our measurements off the model. (I stood farther back.) The mechanics are easy to demonstrate, difficult to describe. There was nonetheless considerable effort made to do so in another thread, beginning at this page.

In a studio setting, sight-size is particularly useful for purpose of critiques, because the instructor can stand in the same place that the student stood to view the model, and the instructor will see exactly the same thing the student saw (or, more often, should have seen). There's very little wiggle room for quibbling over accuracy -- the drawing or painting either looks exactly like the model or subject, or it doesn't. (This does not deter some students from trying to squeeze extra quibble into the wiggle, rarely a successful effort and usually the mark of a beginner.)

It really pays, though, to learn the relative sizing method as well. I found myself in a portrait workshop never having worked in any but the sight-size method, and because of the nature of the studio space and the huge number of participants, I couldn't proceed that way. Relative measuring was a wheel long since invented, but I'd never ridden on that bike before, so I wasted precious workshop time having to reinvent relative sizing for myself.

By the way, Peggy Baumgaertner's video presentation contains a great deal of discussion and demonstration of working through relative measurements.