2018-12-03 - The Epsilon Project - Down to Earth

[Chakat Blackspots]

When I was a kid and mercury vapour lamps were everywhere, they always seemed to have a beautiful purple tint to them. But when photographed, they always come out green. I have no idea whether that's due to a difference between our photographic processes and the way the eye works, or whether there's something slightly odd about my colour perception. I have drawn them something like how I remember them as a kid.

Ok, the reason why we see blue/purple from mercury vapor, is of course, when mercury is excited, it produces blue into ultraviolet light.  If you are referring to digital photography, the sensor doesn't understand the frequency of light it is detecting, so both UV and IR show up as green.

[Tapewolf]

Ok, the reason why we see blue/purple from mercury vapor, is of course, when mercury is excited, it produces blue into ultraviolet light.  If you are referring to digital photography, the sensor doesn't understand the frequency of light it is detecting, so both UV and IR show up as green.

Makes sense.  This was probably fujifilm, though.  With a bit of effort I could probably dig up the negatives and see exactly what stock I was shooting.  It's interesting that both RGB and photochemical cameras respond the same way to out-of-band wavelengths though.