Photo

                                                         Beach of the sea  illuminated by a mercurial lamp. 10 minutes after the sunset.  

Camera Rolley SL 66. Slide.

     The beach was illuminated by two streetlamps. One of them had a usual light bulb while the other one had a gas-discharge mercurial lamp. I appreciated the situation at once & told my wife that we had to take a picture of this beach at sunset the next day. She was quite astonished as she couldn’t see anything worth photographing. I started to explain that the photo’s foreground would be bright green with a red strip behind it, followed by the dark sea and, eventually, by the pink sunset sky in the background.
However it was my imagination only. Actually my eye was observing the white sand of the Azov’s seaside speckled with numerous footprints of holiday-makers & the dull glow of the fading evening light above it.
     The next day half an hour before the sunset I was busy running about the beach and looking for the local electritian. I had to persuade him to turn on the streetlamps a bit earlier than usual thus eliminating the risk of missing the moment when the sky would still preserve its saturation while the sand would no more be lit up by the sun rays reflected from the blue sky.
     The matter is that you should use your technical knowledge about colour temperature of light sources.
Mercurial lamps used in large industrial premises or in streetlamps bring a lot of trouble to photographers. They give off an unpleasant green colour when daylight film is used which, by all means, needs correction. Daylight film is intended for natural sunlight only or for electrical flashes. (5600 degrees). Therefore it can reproduce the colours of various objects precisely enough provided they are illuminated by above-listed sources of light. But if daylight film is used for photographing in the room illuminated by incandescent light bulbs, halogen lamps or candles the surroundings on the photo will turn red because colour temperature of these sources of light is much lower than that of the previously mentioned ones. (3200 degrees for halogen lamps, 2800 degrees for incandescent lamps & less for candles)