Another cold elliptical reflector source

[TaskMaster]

Those do look nice. Can I ask what that SoLux bulb was you used with it? Now yours is all with the 7" Lilliput, correct? Would you still think such a light engine is sufficient for a 15" setup?

[ace3000_1]

Can I ask what that SoLux bulb was you used with it?

Heya buddy none, that was just an artical cut out in my other thread to show a eficientcy rating of having the lamp mounted sideways compared to vertical. I got that from the solux site.

I use a CDM-T metal halide lamp.

Now yours is all with the 7" Lilliput, correct?

It sure is buddy

Would you still think such a light engine is sufficient for a 15" setup?

Maybe, it depends on what specs you can get in the ellipsidal range, you realy have to have a frensel thats going to match the angles of the reflector otherwise you will get a hot spot.

There is a small formula to go by. Its 6x9.

6 = focal of the reflector
9 = the width of the lens

So for an example, if we had a 6inch focal on the ellipsidal, we could iluminate a 9inch wide frensel. I got this from a stage lighting site, i normally just draw the focals out on paper and work it out that way. You can be sure to see in reality what you are after then.

To me that calculation is abit rough and debatable as i could use a shorter focal reflector on my setup, but i would just have a beam thats too wide so then we would waste light and need a condenser. With a beam thats too wide you will get added distortions too, as the beams dont match the frensels focal lines, or rings.

If you go along those lines no problem.

Trev

[18wheeler]

I haven't heard from the manufacturer. But got a quote from a retailer in beijing. they have:

Model: HB1220-T080
D = 80mm
d = 22mm
H = 35mm
F1 = 15mm
F2 = 120mm

temp: -40 ~ + 420C
life: 1000hr

The price is 230 Yuan ( or about $30). Not cheap but not too expensive. let's see if we can get better price from the manufacturer.

[18wheeler]

well, here is the ellipsoidal reflector Ace was talking about:

edmund optics reflector

about doubled price at $61.

Trev: did you hear from your source yet? does your reflector also have a lifespan?

[TaskMaster]

Does the retailer do mail order or have a web site?

[chooch]

With a H=35mm for the hb optical reflector... its seems a lot of light would be wasted because it's so shallow. The Edmund one should capture much more light than the 80mm HB optical one. If the Edmund reflector was 15-20mm smaller in diameter and with slightly shorter f2, I think it would be perfect.

Also, just so you know, PTI:

http://www.pti-nj.com/obb_1a.html

They offer their reflector as replacement parts. The f/1 reflector may be a worthwhile candidate if it's affordable. Only draw back is the reflector is billet aluminium then coated and not a cold reflector. I guess we could just use a cold mirror to solve that problem. I sent them an email a month ago and never got a reply.

Gordon

[TaskMaster]

I just called them and the cheapest of the three they stock is ~$695.00 (which was the f/4.5).

[ace3000_1]

Trev: did you hear from your source yet? does your reflector also have a lifespan?

Nagh not yet mate. Ill see what i can do tomorrow.

I dont know if mines got a life either, it probally has, ill try to find out tomorrow. I remember back in the day ( you might too infact) that cold mirror has a life span aswell, can you remember what it roughly was? Im sure it was a fair while.

To be honest i dont think it makes that much of a diff, (within reason), as ive got a cold parabollic reflector here thats had over 4krs in it and its still fine. The original was a 2k hr lamp, the guy got it redone with a new lamp (cheaper alternative) and ran another 2k hrs through it. He only sold the lamp because the projectors lcds screwed up, otherwise he said he would have gotten the lamp redone again. That reflector is rated at 2k hrs.

Even if we have to replace the reflector say after 10k hrs as its on its last leggs we are still winning, even if we had to buy a reflector at 5k hrs. Just think, most of us now throw our bulbs away at half life due to them being dim, with this setup im nearly 100% sure we could use the bulb for its whole life, (well, atleast 75% ) so we can save there on bulbs too. My bulb isnt new btw, im curiuos to see just how bright it realy is on a new one lol.

Trev

[18wheeler]

Originally posted by chooch
With a H=35mm for the hb optical reflector... its seems a lot of light would be wasted because it's so shallow. The Edmund one should capture much more light than the 80mm HB optical one. If the Edmund reflector was 15-20mm smaller in diameter and with slightly shorter f2, I think it would be perfect.
Gordon

Actually it is not that bad.

[TaskMaster]

Do you know the size of the hole to accept the bulb on the chinese unit?