400W Diazo Metal Halide Lamp

This was my first ever HID lamp, and it sparked my interest in lighting. Got it for cheap at an electronics surplus store, and I had no idea that it wasn't a typical lamp until I powered it on and it was purple. Long story short I was not very knowledgeable back then and did some things to it that I shouldn't have. Now the electrodes are a little sputtered, and sometimes the lamp starts to cycle.

I believe this lamp contains halides of indium and gallium, the indium being the blue portion of the warmup and then gallium adding purple to the mix once it evaporates. Unsuprisingly when this lamp first strikes it is the typical mercury teal color.

I was going to get a close up shot of the arc with some polarizing filters, but when I turned it on again to try to do that the lamp would no longer warm up past the indium blue stage without cycling off. Oh well. Maybe I could have messed around with the CWA capacitor to get it to be stable but that will have to be for another time. I am open to giving this lamp away for a trade but haven't worked that out yet.

Being for use with diazo printing, this lamp emits some sort of UV wavelengths. I don't know exactly what they are or if they are harmful but I certainly wasn't looking right at it. Judging by the blackened pinch and flare seal this envelope is almost certainly leaded glass, so I would guess that it blocks most of the super duper harmful short wave stuff, though I don't know for sure.

It was not in its original box and the etch is practically non-existent, so I don't know who made it. It is also not marked with a burning position so I'm just guessing here really. Pretty sure it's not base-up only or base-down only as those usually have different refractory coatings. I haven't seen a lot of these lamps so I figured I would share. An admittedly cruddier picture of this lamp lit is my profile picture across many sites.