color shifts with different ballasts

[sowellj]

I asked this over in the equipment forum but was unable to get an anser so I thought I would try here. I have a quick question on color shifts associated with different ballasts. For example, I have read that hqi ballasts run radium bulbs w/more of a white color when compared to electronic ballasts, which run a bit more blue. No first hand experience, just what I have read. However, when you look at Sanjay's sight, there is no wavelength shift (i.e., color shift) with the same bulb on the different ballasts. The intensity is different, but no x axis shift. The spectra are essentially superimposable (on the wavelength axis). Thoughts?Thanks in advance for your input on this.

 

[dots]

Manufacturing inconsistencies, power connections, and fluctuating incoming power, heat. The colors from the bulbs changes as they age, increasing in resistance. The ballasts can fluctuate to try to compensate for these inconsistencies as they try to draw the same current. It should be noted our "ANSI" ballasts are not a perfect match for the European bulbs and don't preform at thier optimal place.