The third session of the beginning drawing class was about sighting and measuring. Both techniques involve holding up a straight reference object like a pencil and using it to capture objective information about the subject as projected onto the picture plane.
Sighting captures an absolute angle on the picture plane. You hold the pencil up so it’s parallel to the feature you want to capture, and also parallel with the picture plane. Then you move it over to the paper and transcribe the angle onto the drawing. Somehow, you’re supposed to be able to hold the pencil at the same angle while moving it to the paper. I found it difficult to make sightings accurate enough to be useful.
Measuring captures a distance, as projected onto the picture plane. You choose a convenient feature of the subject to serve as your reference distance unit. Then, holding the pencil at a constant arm’s length and parallel to the picture plane, you mark that distance with a finger on the side of the pencil. You can then use that as a sort of ruler to count out relative distances elsewhere on the picture plane. In particular, you can measure how many distance units your entire subject spans, horizontally and vertically. With this information, you can first choose a portrait or landscape orientation of the paper, and then compute how large your reference unit should be on the paper in order to fit.
Presbyopia doesn’t make this any easier. I wear eyeglasses with progressive lenses. That means I have to tilt my head to focus at different distances. But when I tilt my head, it screws up the line of sight past the pencil to the subject. To make a measurement this way, I have to choose a compromise focus distance somewhere between arm’s length and the distance to the subject, and just accept that both the pencil and the subject will be a bit blurry.
Because you’re actually measuring and not just eyeballing it, it’s easier to avoid fooling yourself with mistaken assumptions about what the subject ought to look like. And, because you always hold the pencil parallel to the picture plane, you are measuring distances as projected onto the picture plane, not actual distances in space. That means you automatically get foreshortening and perspective for free, to whatever extent your measurements and sightings are accurate.
Our test subjects for measuring and sighting were stacks of three boxes. How very static.
You can see I got the scale about right, but the centering is off. We colored in the top surfaces to help evaluate how well we had reproduced the shapes: not all that well. The extra line on top of the middle box shows where its far edge ought to have been, relative to the top box.
All this measuring and sighting is very time-consuming, especially when you’re new at it. Unusually, I was a little faster at this than some of the other students, so I had time to start a second drawing.
The homework assignment was to do the same thing again: draw a stack of three boxes using measuring and sighting. Fill up the picture plane. Center the biggest box. Shade the top surfaces. Don’t erase the construction lines.
Homework 3. Grade: A. Pia’s comment: Excellent!
I didn’t really intend for the top corner of the top box to kiss the edge of the paper like that. Tolerance buildup. Lesson learned: allow more margin for error.
This is the first time I had to draw straight lines (not counting the blind drawing). These aren’t even freehand lines, they are drawn first in vine charcoal and corrected as necessary, then traced over with charcoal pencil. And the lines are still somewhat wobbly.
The last segment of the class was devoted to a video presentation on one-point and two-point perspective. It treated them as radical innovations discovered by great Renaissance artists. Pia and the video both emphasized that perspective is just one way of representing depth. I can’t deny that other traditions have used other conventions to show depth, but I can still argue that perspective isn’t just another convention. Perspective is how the world actually works. The proof is in every photograph ever taken. I find it difficult to believe that people before the Renaissance couldn’t see that their art wasn’t realistically drawn, or that talented artists were unable to reproduce what was before their eyes.