For Still Life Painting last Thursday, I chose to paint a scene that wasn't officially part of the setup. This onion was leftover and was laying on top of extra fabric at the base of one of the stools we use to set the plants and vases on.
As I looked at the scene, I noticed a couple of interesting compositional points (through my viewfinder made of masking tape...)
1. The shadow shapes all form triangles pointing to the onion (squint until the picture becomes simple dark and light shapes...then notice what they are doing)
2. The saturation and contrast are intense near the onion (I could have pushed this a lot more, desaturating the BG a little more...like that stool...)
3. The lines of the fabric form a sharp angle at the onion, which (according to Will) draw the eye in and stop it. In opposition, the lines formed by the vase and the shadow shapes are all curving, which move the eye past them swiftly. (Again, that stool is battling for attention due to the sharp angles of its legs, but oh well...)
4. The elements, entry and exit points, are mostly placed along the most pleasing proportions (Will says they are: 1/3-2/3. 60-40, 50-50, and 80-20)
All in all, I was thinking, "How can I compose this picture so that the viewer knows exactly where to look?"