This was taken at a candle-lit walk in Uppsala, Sweden. 1000 candles are set out in the forest, and visitors are encouraged to bring lanterns with them for the walk.
The first challenge was finding a viewpoint that included the old mill and many of the candles as possible, and then a subject that wasn't wearing black. This young lady was perfect. Then I needed to set up the tripod on the stairs and get the subject in the right place. Background exposure was easy to judge (3s @f6.7, ISO 800), but getting the right amount of fill flash to freeze the subject and balance her exposure took a couple of rounds of trial and error. All this had to be done very quickly, as the stairs were the only access to the walk, so I was very lucky that the perfect model was also one of the first to arrive.
Post processing was some minimal dodging and burning and a vignette.
Nikon D800 + Nikkor 14-24mm + SB800 flash