2 seconds exposure, cable release, at f9 and ISO 800
The glowing object in foreground is one of the stranger things in my collection of strange things. It's a lump of slag from a vat of "Vaseline glass", which is colored pale yellow by the addition of uranium oxide. This sample has quite a bit of uranium and is emitting a lot of beta particles, as the antique Geiger counter -- a Civil Defense relic -- behind it shows. The green glow is fluorescence due to a small ultraviolet light placed just in front of it. The overexposure of the nearer parts of the glass is deliberate -- I wanted to capture the Geiger counter illuminated only by the fluorescence.