View Full Version : Optics Gurus I am in need of help.

05-24-2015, 06:59
Here is my situation, I am in over my head on three long throw spot lights that were in battered some what working condition. Phoebus ultra arc ua120, problem is the ballast is undocumented and impossible to replace or have repaired when they quit. They quit quite often as I bought them from a company who I have used them for years. Worse off it uses a bulb with terrible life and is almost impossible to get any more as they are no longer produced. GE MARC-350/16T 350W/45V $400 price tag and <50 hours of run life.

I bought up some used HES Studio Color 575's for the excellent heat sink, reflector housing, Rock solid Ballast and ignition source and bulbs come in two kelvin varieties and have great life and decent price tag. Well I set it all up and I cant seem with tinkering get a much of a beam out of it. I played with focal length of the bulb projector and the first lens and i cannot get this 575w 6000k bulb to put out half the brightness of the factory still working light which is only 350w at 5000k.

The spot light is a three lens system the rear or relay lens is two lenses in a housing and I have played with multiple combinations here is what the optics path looks like Bulb<--|)(|-- |) ---------|) the last two move to adjust the long throw and the focus of the beam the first double lens is normally fixed. I can take some pictures and will pay anyone who is in driving distance to take a shot at getting some optic solution fixed up for this my optics assortment is small and they are all small physically due to them all being of laser nature. I am guessing the first optic will need changing or something before it to tame the light before it hits it as the front two lenses are about 6" and 10" and most likely not a good idea to try to replace. I have about 3 weeks to get these into working shape for an event I need them for. New lights in the long throw variety are way out of my budget so retro fitting these are my only viable solution, but with my limited knowledge of optics I don't stand a chance on my own.

Here is the bulb stats from the original bulb

Wattage: 350W, 350 Watt Watts
Voltage: 45V, 45 Volt Volts DC
Base: Special 2-Pin Plug
Glass: PAR24, PAR76 Dichroic Mirror, PAR-24 (8ths of an inch), PAR-76 (millimeters)
Color Temperature: 5000K
Average Life: 50 hours based on one hours use per start
Initial Lumens: 50
Working Distance: 52mm, 2.05"
Burn Position: H, Horizontal
Electrodes: Solid Tungsten
Atmosphere: Argon
Lamp Type: Quartz Halogen-High Intensity Arc Projection Lamp, Pulsed Xenon
Arc, Gemini, Marc
Socket: High Intensity Arc Lamp Connector LC-1C

New bulb in the reflector housing is a MSR575/2