Above is an illustration of an easy, non mathematical way to find the power spots on a rectangle. This may not be perfect mathematically, but it is close enough for making paintings. However I can put my finger on the powerspot at a glance. But maybe I learned that once and forgot, possibly everybody can, I dunno. Either way, here is the pool hall geometry way to get there. Draw a line from corner to corner, both ways diagonally across the rectangle regardless of its proportions, then mark the point half way between the center and the corner of each quarter of the lines. And there they are, leering at you, powerspots.
I am announcing another workshop. Seems like I am doing a lot of those. People call me up. This one will be "Seascape Painting for the non amphibian". This will be held at the Rockport Art Association, in Rockport, Massachusetts on Sept 10-12. Weather permitting, I will teach both inside and outside.and show you how knowing the anatomy of a wave creates the means to craft its appearance. This is an RAA schedule event so talk to them if you want to be there. Their phone number is 612 546 6604.
In the comments some one asked me to show the powerspots operating in one of the paintings from last night, so here that is.There are the four power points in this Bouguereau. Each of them is in an important place in the design. The stern of our heroine is place right on the lower right point. Which is where Bougoureau placed it so we would be sure not to miss this attractive young woman. Over on the left power point the nymphs foot comes in and intersects the line right there. Because their is downward weight implied in the leg, she "stands" on the power point. That gives plenty of emphasis there.
The upper left point is the nymphs face, looking down into the action. Her gaze directs us or returns us down to the laddered stack of arms at the middle of the canvas where the pale flesh of the nymphs contrasts with the deeper more ruddy skin tone of the Satyr.
There is some kind of a passing reference to satyr in mythology that says they are afraid of water, that's why these naughty woodland sophomores I trying to throw him in the pond. It was a typical convention in classical painting to portray men as being russet colored and women as being pale. Society's taste for tanned woman came much later. That's why you see those paintings of Victorian ladies out with their umbrellas, they weren't avoiding the rain, they wanted to keep their complexions as pale as they could. Being tan was for people who had to work under the sun. Incidentally, when I see a contemporary painting with a woman in a long dress and a parasol, I think 'heightened cheese content'.
A number of readers have e-mailed me questions. I love that, but I can't answer them all immediately. I will work in the answers to your questions when I am in a transition from one series of posts on a subject, to another.