The application of the Golden Section in Adobe Photoshop is quite easy to set up, and provides an invaluable template for composing image composition.

The Golden Section is a fundamental ratio of composition defined by the proportions 1.61803 to 1. It was defined in classical times and informed the proportions of amongst other things the Parthenon in Athens and Notre Dame Cathedral, Paris. It is still very much used and can be found in lots of modern designs.

I have made a Golden Section mask in Photoshop so I can slide the main image layer containing artwork, photograph etc around to fit the intersections and boxes within boxes. To maximise the photograph frame area I used the frame width as the starting point and then worked out the height and put a guide in. It was quite easy then to put in diagonals made at 1600% zoom for precision that mark the intersection points of the other boxes that diminish in size following the Golden Section Spiral. I only did 3 iterations. There is a wonderful book Geometry of Design by Kimberly Elam; Princeton Architectural Press, ISBN 1-56898-249-6 that sets it all out and explains everything very concisely and elegantly. The book then goes on to deconstruct design classics in geometry terms using tracing paper overlays with grids marked out showing the symetry. The book is geek heaven and I thoroughly recommend it.