Canon EOS 5D, Canon 180 mm macro lens, extension tubes, tripod. Manual focus, manual exposure (0.8 seconds at f/5.6), ISO 100.
I was once again poaching flowers from a coworker's desk. This time I spent my lunch break photographing this dahlia (behind some small blue-purple flowers I have not identified) sitting on my desk. This image was made with the dahlia backlit by indirect sunlight through a north window. There were also fluorescent lights above, making color balance a challenge. My solution was to convert the RAW file twice--once for the natural light and once for the artificial, then blending the two with a layer mask.