Iwasaki EYE MT70SDW arcstream.

Looking at the arcstream of a 70w EYE Colour Arc 3500k open-rated quartz metal halide lamp through a 180mm macro lens and an ND1000 filter.

I'm not sure if this lamp needs a couple of hundred hours to stabilise but this it massively colour shifts depending on which way round it is when operating. When you run it with the sealing pip facing up then a load of condensed halide salts form at the bottom and makes the light emitted from the bottom much warmer than is emitted from the top.