Wirgin of Weisbaden Edixa Reflex-B circa 1960. The dust that some would have seen was, in fact, nearly 50 years of pitting and corrosion which showed up under the harsh light of a flash. Sorry about any confusion.

The actual image is the shutter speed dial as others did work out. "B" for bulb, "O" for exposures longer than 1/25th of a second which were controlled with a separate lever.