The purpose of this exercise was to study the effect of the subject’s location on the illusion. I sketched a titmouse in each of the four quadrants of an 8×10 page and was underwhelmed.
I used graphite for the first sketch. Since I wasn’t in the mood to draw, but I was in the mood to experiment, I used some bamboo pens to sketch the other three birds. I was surprised at how well a sharp piece of bamboo works as a pen and at how poorly I handled it.