My latest drawing for the challenge done in three separate sittings over three days this weekend in pastel.
First sitting establishing just the light and shadow side of the form using just two values (from the five value system I use and teach).
The second sitting going to five values, adding halftones to the light side of the form and establishing the lightest planes, using three values for the light, then working on the turning edge and reflected lights, using the two remaining values for the shadow side.
The third and final sitting, this morning, for just half an hour, with a fresh eye, punching up the darks and softening and hardening edges.
The reference for this pastel drawing was a cast I saw years ago in the cast room at The Philadelphia School of Art. An amazing place.