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Old 20th January, 2005, 02:29 AM
Chernobyl's Avatar
Chernobyl Chernobyl is offline
Projector Wizard
Join Date: November 2004
Location: UK
Posts: 594

I've found the right bulb type to use!

its a Metal Halide HQI-ST type (aka HQI TS) 250W or 400W.
The 250W are around 20,000 Lumens, the 400W about 35,000 Lumens !!!
(The original 400W projector bulb is 13,000 Lumens)

Its is a compact double ended Metal Halide bulb that will mount fine at the focal point of the current bulb without cutting the case open.
The colour temp varies, I have found some in the 5000K to 6000K range though.
Some have built in UV filters too like one made by Osram, but boy are these hard to track down. I dont even have a part number for it yet!

Using different Ballasts (electrics) and/or Dichroic reflectors, the colour can be varied quite a bit. Some Dichroic reflectors shift the bulbs colour temp all by themselves!

The bulbs are usually operating somewhere near 50% of their max brightness by the time they die and some do colourshift a bit too. There are bulbs around that are resistant to colour shift, not sure if they make them in this type though.
I think a 400W bulb might be best to keep the brightness up.

The heat produced is much less, as more energy is converted into light, so a cheaper triplet lense 250W OHP may be able to take one of the 400W bulbs!

I'll be making some phone calls tomorrow to see where they can be found in the UK.

Oh yes, they are damned cheap.
10,000 hours plus, 250W around £20, 400W around £40.

not sure of the electrics price, but a combined bulb with electrics can be found for about £60-£70.
2.9m DIY home made LCD PC projector !
Venice 3000+ (1.8GHz) @ 2.7GHz, 1.4V
Stock air cooler
X1800XT clocked to PE
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