Technical (geek) Bit: I encountered quite a few issues taking this image. I had walked up and down Wenceslas Square during the day, sampling the sausages (yum!), and saw the roses standing up proud from the graphical swirls of the bushes underneath. I took a quick composition shot then and knew where to come back to at night.
Here are the problems: Depth of Field, night photography (long exposure ), gentle breeze, 3 exposures (-2,0,+2).
I could not get the depth of field I wanted without stopping down to the smallest aperture and hyperfocusing. When I did that, I had really long exposures and with the breeze, the bushes and especially the roses were completely blurred out. I could have upped the ISO but for HDR, that would have created post-processing issues.
This is where the tilt-shift lenses pay for themselves. I whipped out the TS-E 24mm F3.5L II and shifted it UP to get the top of the bushes and then tilted it DOWN slightly to change the plane of sharpest focus (depth of field). This allowed me to then use a wider aperture for a relatively short exposure times to keep the ISO low and the rose bush sharp enough so that it was not all blurry.