Thames Festival Finale Fireworks
The display was presented by Pains Fireworks.
A delay in the start of the display from the scheduled time was attributed by the crowds to incompetence by "Bumbling Boris" Johnson - the London Mayor - part of the British patrician "limited liability" ruling class. "I'm in charge, but if anything goes wrong, somebody else will be sacked..."
Like the extreme audio dynamic range of Taiko or Samba drumming, it is not really possible to record the visual brilliance of fireworks with a camera. You have to experience firework displays live, in person. These images were taken at the slowest sensor speed (ISO 100), maximum aperture (to minimise diffraction "glare" effects) and with a variety of exposure times ranging from about 0.5 to 2 seconds. The intense light caused some "bleaching" of the paths of the lights, and so the colours have been enriched if Photoshop. (In retrospect I might have used a slightly smaller aperture.)Additionally, the river and land areas have been selectively lightened in Photoshop. Fortuitously, a gentle breeze caused the smoke to drift eastwards, away from my vantage point on Waterloo Bridge, so the view of the fireworks was relatively unobstructed by smoke.
Fireworks date from at least the 7th century in China. The colours are believed to have been conventional incandescent "black body" bonfire colours: red, orange, yellow and white. (It is theoretically possible to produce pale blue just by heating, but this requires impracticably high temperatures. It is not possible to heat something to "green hot" or "purple hot".) It is believed that from about 1830 in Italy metal salts were introduced to produce a wider, richer hued, spectrum of colours by chemical luminescence. This approach can be problematic, as it can be difficult to create stable, practical, chemical compositions. It has been suggested that some shades of green are still difficult to achieve.
Firework Colours [The chemistry of Fireworks by Reema Gondhia, Imperial College]
History of fireworks [Pyro Universe]