Claus Thiim captured this beautiful image of fireworks showing both in-focus and out-of-focus burst of light. The trick is to capture most of the photograph while focused on the fireworks, and then throw the lens out of focus shortly before the shutter closes.
On a slightly related note, check out this crazy video of an entire fireworks display released in just one minute (something went wrong).
Next time you’re attend a fireworks display, try shooting your photographs or video out of focus. This video by Danny Cooke is a pretty beautiful look at what you can achieve by doing this. What’s more, if you focus on the spectators in the foreground, it looks like they’re watching bokeh fireworks as well!