Yellow Rose Super Close-up

Give me a rose, the Canon MP-E 65mm Macro Lens and a flash and I can get lost for hours. At this super-close focus distance, the DOF (Depth of Field) becomes extremely shallow. I chose to keep the edge of a petal in focus and to allow the rest of the rose to smoothly blur into transitions of color.
 
At this focus distance, even a macro flash results in some shading. Here, I used this shading to my advantage.