One of the hardest drawing skills for me is visualizing the picture plane. And as I struggle to write this, is apparently also difficult for me to describe. Essentially, the picture plane is the imaginary surface on which your object is projected. It is what links the 3D object to the 1D drawing. It is how the flattened image should look.
If you can visualize the picture plane properly, then your drawings have the proper perspective. They look like they are representations of a 3D object. If you cannot visualize the picture plane, then your drawing looks like a bad Escher print. Something is clearly wrong with the world.
Drawing from photographs is easier because the image is already flattened out. The turtle I drew previously was from a photo, so I could focus on just reproducing what I saw instead of trying to puzzle out how to represent a round object on a flat piece of paper.
In Drawing on the Right Side of the Brain, you are encouraged to use a literal picture plane- a small acrylic window that you trace your scene on with dry erase. Once you see how the object should look flattened, then you can draw it yourself on paper. This makes a huge difference.
Below are two drawings of the same stool done at different times. One drawing uses the picture plane heavily and the other one doesn’t.
In fact, the no picture plane drawing was so horrible that I stopped drawing for 4 months because I was completely discouraged. This is certainly something I need to work on. I need to balance the fun of being able to draw something recognizable (working from a photo or the acrylic picture plane) with harder and less fun sessions where I try to visualize the picture plane in my mind. (Hmm, I cannot actually visualize, so this might be part of the problem. I’ll post more about that someday.) The fun sessions are less likely to improve my skills, while the harder sessions, while likely to lead to improvement might be too discouraging.