This was awesome, thank you Marshall. I tried using my triangles during the Isometic Optical Illusion homework assignment and was struggling in a dramatic fashion (many huffs and puffs). This was a very helpful illustration that I will practice a bunch!

Finally finished this assignment. For whatever reason, isometry was not clicking in my brain. I first started by trying to make my own optical illusion, but quickly decided to transition to a study of Sandro del Prete, named 'The Crusader of the lattice fence'. I did a much simplified version, and that direction alone helped make things click. It was fun to work through the puzzle, and definitely gave me a greater appreciation for this art form and style. I learned: My pace of drawing a straight line is improving in consistency How to effectively use my triangles to keep lines parallel What I need to continue to improve: Continued proficiency with tools Shading Hand pressure control This assignment was really fun once I broke through that first barrier! Happy to get out of my comfort zone for a while, and definitely will practice again.

When doing these line exercises, I found myself in situations where I could not keep my pinky in contact with the paper due to getting close to the right edge of the page (I am a righty and really enjoy the feeling of keeping my pinky on contact with the paper). Is it ever appropriate to rotate your canvas so you can keep contact with the page? Of course, these are just lines with no consequence other than improving muscle memory, but that made me question if I should rotate my sketchbook at all, or if I am creating a bad habit. I know there are truly no hard and fast rules, but wanted an/some opinion(s)!

This is great and reminds me of the lessons Peter teaches in his 'Dynamic Bible'. One of the best gifts I ever have received was that book. Thanks Mom!

Do we know if he was consciously using perspective here rather than working very accurately from observation? Ok I realise that water is a moving target, so to speak, but if you look at it closely for long enough you can get an idea of how it arranges in space over time. Much of the skill then is distilling the essence of these dynamics into a representation that makes sense to the observer. Obviously, you have presented this as part of a perspective course and I don't doubt your analysis, but the purpose of perspective is to accurately represent the 3D world on a 2D surface. So I assume that it is possible that an artist sufficiently skilled in accurate observation could produce perspective views without relying on formal perspective techniques.