[click on image to see a larger one]
Double hexaptych (top to bottom) of Visual light; emitted UV 320-390nm, 310-350nm, 290-340nm, 280-315nm, 304-322nm. Right side is morphological gradient filtering of left side:
This reveals, that the broadband UV image shows a much broader, but less detailed gas flame, the images shot with narrow(er) filters however, shows a much more detailed flame image and is useful to judge how efficient the gas combustion process is, 313nm being the emission peak wavelength of the OH radical.
I have previously written about that HERE.
Stay tuned, more will follow on that fascinating subject...