MH bulb with Enclosed Luminaires - What do you think?

[ywh]

Rolm

why you didnn't deal with bulbs that are (~12mm) in diameter?
HQI bulb is made in osram,like this :
http://photos.gznet.com/photos/1013684/1013684-5CIqI$PG5ilv194fZsCLICV11SsbBI.JPG
http://photos.gznet.com/photos/10136...7k7eqho2NQzj61$ZNRH7bG.JPG

This is 250w osram:http://photos.gznet.com/photos/10136...jRoQMJQe2qazsk!RZmrALtw6kK.JPG
my firend using it :
http://photos.gznet.com/photos/10136...jKEHnAh5wc9fiw$$wjvEaFP2m.jpg
http://photos.gznet.com/photos/1013684/1013684-m$hSAv7V!pkm7nvEz1IqQlfmlgdA8Q.jpg



He got a 3M 1720 PROJECTOR ,and change the lamp.
http://photos.gznet.com/photos/10136...kJcK53sZkb.JPG
http://photos.gznet.com/photos/10136...w9zaEr7EVj.JPG

[Rolm]

ywh,

I decided not to deal with the HQI bulbs for 2 reasons:

(1) price. My bulb is about $20, whereas a comparable (400w) HQI is rare; the only one I found was ~$250.

(2) precision. If I deal with a larger bulb, I don't have to be as precise with making the reflector. You and your friend have the advantage of working with a premade system, whereas I am making everything myself.

Reason (2) is probably why you get such excellent results with a lower wattage bulb. You have a premanufactured bulb holder/reflector/lens that is very precisely made. There is little chance that I'm going to be able to make a precise 2" (50mm) spherical reflector in my home workshop. However, I have been able to make a 12"x14" (30cm X 35cm) rectangular reflector that can focus the light into a 1/2" (12mm) band.

As noted, I have since abandoned the concept of a "rectangular" reflector because it simply doesn't reflect enough of the available light. However, I am still going to try to find a way to use the $20 bulb.

I have a question, perhaps I have missed the answer in some of your other postings: I looked up "3M 1720", and according to all info it uses an ENX bulb. So where did you come up with the HQI bulb holder/reflector/lens setup? I would be VERY interested to find this out...

[rusty42]

this looks helpful.. http://www.hellolights.com/methalparref.html

[Wally]

Hey Rusty, I've got one of those. It's close but no cigar. Not much better than a coffee can.

[ywh]

Rolm

once again for that picture

HQI bulb is made in osram,like this :
[IMG]


http://photos.gznet.com/photos/1013...s7k7eqho2NQzj61$ZNRH7bG.JPG[/IMG] [IMG]

This is 250w osram,you can get it everywhere.
http://photos.gznet.com/photos/1013...bjRoQMJQe2qazsk!RZmrALtw6kK.JPG[/IMG]

my firend using it sram,240w,US$:40,very longer live,more than 10000H,it is evry cheap,and the 3M 1720 PROJECTOR ,US$:200


You 're going to be able to make a precise 2" (50mm) spherical reflector in your home workshop. but the reflector will to be rust in heat light

[Rolm]

ywh,

Ok, my research shows that the 3M 1720 uses an ENX bulb like this:
<img src="http://64.95.118.51/images/opti/d1/09/dfe350ca9976b6606d64ea91e64e659c1-resized200.jpg"</img>

But you are using this assembly to replace the ENX assembly:
<img src="http://photos.gznet.com/photos/1013684/1013684-gMlbjRoQMJQe2qazsk!RZmrALtw6kK.JPG"</img>

Where did you get this <b>entire assembly</b>? Not just the bulb, but the <b>whole thing</b>: lamp holder, bracketry, reflector, lens, the entire assembly? Is this the assembly that came with the 3m 1720, and if so did you just add the HQI lamp holder and make a reflector? If so, how did you make the reflector?

The reason I seem so confused is that this assembly appears to be very different from the standard ENX bulb holder, and therefore the <b>entire assembly</b> would be required to replace and ENX lamp with your 150/250W HQI bulbs.

I currently have a 3M OHP that uses the ENX bulb, and my bulb assembly doesn't look anything like this; mine is about 1/4 the size of that one, and doesn't use any lenses at all.

[ywh]

3M 1720 uses an ENX bulb like that but has not reflector


My friend get thiat entire assembly at 3M,He give it a new bulb, a lamp holder,the bracketry, reflector, lens came with the 3m 1720, he buy the new bulb, the new lamp holder ,only,

[Rolm]

OK, I hope my understanding of you is correct:

All that your friend added to the 3M 1720 was a bulb-holder, the bulb, and the reflector. Other than that, the entire assembly pictured was already in the 1720.

In other words, if I wanted to do the same thing, all I would need is:

(1) 3M 1720
<img src="http://www.unitedvisual.com/jpeg/MM1720.jpg">

(2) an HQI bulb
<a href="http://store.yahoo.com/lamps-now/1510hqidoube.html">
<img width=250 src="http://store2.yimg.com/I/lamps-now_1717_1043712">
</a>

(3) HQI bulb holder
<a href="http://www.hellolights.com/25lamholwitb1.html">
<img width =250 src="http://store2.yimg.com/I/lamps-now_1719_94164">
</a>
(4) home-made ~2" reflector like this:
<img src="http://catalog.sciencekit.com/ProductImageLib/30/30538-75g.eps.jpg">

I would <b>NOT</b> have to buy any parts from some other OHP to make it work, right?

If you can verify this, then I will probably start buying some of these things. I just managed to mangle some of the parts I took from my other OHP, so I'm looking to buy anyways.

[ywh]

no !
3m 1720:the bracketry, reflector, lens came
My friend bought the new bulb, the new lamp holder,
your 3m 1720 is not Chinese 3m 1720 !why ?Chinese 3m 1720 is:
http://www.3m.com/intl/cn/office/dem...uct_m1720.html







250W HQI bulbs is right for 100" screen.
if 150W £¬dont more than 70"screen,My friend using 250W HQI bulbs
but ,250W is very expensive at HELLOLIGHTS.US$:40 in China

[Rolm]

Hm, I suspect you are right, and the Chinese version of the 1720 is different than the western one.

I suspect that your friend's 1720 originally used an EHJ bulb. Am I correct?

OHPs that use the EHJ-type bulbs are probably the ones that are capable of being easily upgraded to a Xenon or MH HQI bulb, because (I am pretty sure) that they all use the apparatus pictured earlier in this thread, with the seperate reflector and lens.

As noted, the western version of the 1720 uses an ENX/FXL style bulb, and therefore has no lens and the reflector is built into the bulb. If an OHP uses an ENX/FXL-style bulb, it is definitely NOT a candidate for this modification, or at least not as easily.

In any event, I've trashed my OHP at this point (I broke the thermal glass that is bonded to the fresnel), so I'm in the market for another OHP. I will try to buy one that uses an EHJ bulb. If, as I hope, that means that it comes with this apparatus, I will try to do the same mod you have done.

Thank you, ywh, for your patience in answering my questions.