wich bulb? HQI-TS 250W+spherical or HQI-T 150W+par30?

[Rox]

Originally posted by charlie10
I read that the "30" in "par30" refers to size,

parX is not the size, X means the angle of the rays output.
A par60 is twice the par30. Thinking a par reflector would give you paralell light is wrong (it would be par0) but the number is very important.

[Guy Grotke]

OSRAM makes some lovely 250 Watt and 400 Watt MH lamps in their own dichroic elliptical reflectors. Look at their HTI series.

Only problems are that they run for less than 1000 hours, and are pretty expensive. Originally, they made them for medical instruments with fiberoptic lightguides.

If somebody made an aluminum elliptical reflector that would fit a $65 US 10000+ hour lamp, then that would be very competitive with designs that use spherical reflectors and pre-condensor lenses.

[ace3000_1]

If somebody made an aluminum elliptical reflector that would fit a $65 US 10000+ hour lamp, then that would be very competitive with designs that use spherical reflectors and pre-condensor lenses.

They are made for that size of bulb, buy one, they are fairly cheap, from stage places.

Trev

[Me2!]

Do you mean the Altman Shakespeare or something else?

[charlie10]

I googled for "Par30 eighths" and found the following helpful bulb reference.

http://www.servicelighting.com/catal...candescent.cfm

According to that reference, the "30" refers to diameter not angle. Might not be the only measurement system, I don't have the experience to know...

After finding out about the bulb lumen distribution, I'm very curious again about ellipsoidal reflectors.

Tried to look up stage fixtures. Searching ebay for "leko" turns up some options in the $100-200 range, that's for the whole fixture. Seems like a reflector should be cheaper though.

[Rox]

on the link you posted, there are some pictures with more than one par number (par 30, 38, 60). It could be that they use it to mean the diameter of the reflector aperture but i have never seen it before. I can buy a 50mm refelctor dicroic alogens from par12, par24, par36, par42, par 60... all of them looking very similar but the only difference is the light angle at the output.

[ace3000_1]

Regarding me2's first drawing of the elliptical reflector, he is part right. Look up "Etendue".

Etendue is a measure of the area of the light distrubutation, convolved with the solid angle of the light.

Trev

[ace3000_1]

And this is why im going to DMD in a week or 2

Trev