That is an interesting comparison, Rich.

More interesting is how they run , my original lamp, (in the middle), takes literally 20 odd seconds to run up!, the new one takes about a minute! The disintegration of the electrodes in the old lamp must make a slightly hotter arc?, also, as the electrod tips wear down it obviously moves the arc core lower down to the halide dose? On run up these have a vivid blue period, the white gently comes in after with the new lamps, with the old you can actually see the white burst in within about 4 seconds! , I'll have to set another set of 150 gear up and do them side by side?

Would be interesting to get these on a power meter and see what they are doing electrically.