16" long arc lamp the size of my head

[AYT93]

My brother found this while helping clear out a storage space on the campus of Pratt Institute. I dont think its vintage or rare, but it certainly large. I believe its light source is an arc of electricity. Probably mean on the eyes up close when its on. I also wonder how much internal pressure its under.

Sylvania Metalarc M/MS is the model number







I found the little one in this picture a few years ago in an old spotlight and i thought it was big. It looks tiny next to this guy.



I figured i would share the find with you guys, what do you think?

 

[Les]

Yep, that looks like a metal halide lamp, probably from a stadium light ranging in the 1500watt area. The outer glass envelope isn't under any pressure, but the inner capsule may be slightly pressurized. Nothing like a xenon lamp, though! Cool lamp, and if it's any good it could be worth a few bucks.

The smaller lamp is an incandescent; probably similar in use & output to today's BTN, BTL or BTH (500-1000w) and commonly used in fresnels. The lamp may also have been used in radial ellipsoidals, but it's hard to tell if the neck is long enough. If the lamp came from a film studio, all bets are off as to what fixture it came out of -- lamps like that were used in all kinds of projectors, studio instruments, etc back in the day.

Definitely neat stuff though! Looking closer at that Metal Halide lamp, it doesn't look like it has any use on it. Usually after extensive use, the inner capsule will get black on the ends. Could be close to a $100 (retail) lamp when all said and done.

 

[derekleffew]

The Metal Halide Lamp - How it works and history

 

[JD]

Looks like an M1000 BT56 lamp. Just about the most common metal halide lamp. They run about $24 and are in very wide spread use. Both the 1500 and the 1000 use the BT56 envelope style, the 1500 is far more expensive.
Those portable generator/lighting rigs used for event lighting most often use the M1000, so if there is one of those around campus, then you probably found their long-lost spare!