Bringing the 1.5 Rectangle
Into the Golden Section System of Design
Because the 1.5 rectangle (a square and a half) isn't a golden section rectangle, to harness it and bring it into the golden section system of design, you have to use the armature of the rectangle as well as overlap two root 4 Dynamic Symmetry rectangles. In the painting below by Dot Bunn, notice how she uses the armature of the 1.5 rectangle as well as the overlapped root 4 Dynamic Symmetry rectangles for her design. To learn more about overlapping root rectangles, I recommend purchasing Myron Barnstones’ lessons 7 and 10 of his drawing DVD series.
Photographers that shoot the 1.5 format (35mm/digital sensor) should only concern themselves with the basic armature of the rectangle for their compositions. Because the photographer doesn't have control over their designs like the artist that draws and paints, overlapping two root 4 Dynamic Symmetry rectangles in a 1.5 frame is too complicated of a technique to apply while photographing intuitively. To learn more, see the article Dynamic Symmetry for Photographers.
Below is a diagram demonstrating how artists that draw and paint design in a 1.5 rectangle. Notice in the last image that it's two overlapped root 4 Dynamic Symmetry rectangles.