I went back to my benches today. I made some progress, but I'm still not satisfied with the benches themselves, and I'm not sure if there's enough contrast between light and dark. The foreground is mostly in shadow, except for some light hitting the ground between the benches; but there is bright light behind the tree. I may try making it brighter. Unfortunately, this is a lousy photo; the actual painting is brighter.
Just for grins, I applied some filters to add saturation. This image is lighter than the actual painting. My photograph needs work! I need to invest in better lighting -- and I need to find my camera tripod!