Boston Public Garden.  Nikon D300, Home-Brew Rodenstock Heligon 70mm with Nikon f/1.8 focusing helicoid from a salvaged 50mm pancake lens.

This was very tricky.  I didn’t have a tripod with me, and I had to get extremely close to this tiny flower to focus.  As you can see, there is some camera movement evident, but overall I think it turned out well.  The blue-green background is the plant on which this flower was growing.  The DOF is so shallow, that the background is blurred into oblivion.