I found this auction on ebay, its for a 1000w metal halide bulb/ballast and reflector. I dont think the reflector is any good, but it may do until I can fabricate my own.
Here is the link to the auction:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2529436147&category=26219&rd=1
His ebay ID is lytman, for when this auction is deleted.
He will sell these MH kits for $80 each, with $47 shipping to Canada. Shipping to USA will obviously be alot cheaper.
Send him an email, he will sell one to you.
What do you guys think? Should I buy?
Here is the link to the auction:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2529436147&category=26219&rd=1
His ebay ID is lytman, for when this auction is deleted.
He will sell these MH kits for $80 each, with $47 shipping to Canada. Shipping to USA will obviously be alot cheaper.
Send him an email, he will sell one to you.
What do you guys think? Should I buy?
Um for what it is that would be a good deal. However, you would have to run a seperate circut to poerate that by itself, and its still not a point light source, so in short good deal but not for our purposes. Now, if you wanted to start a side buisness growing pot im sure that would be quite sunny. LOL JK " there is no hope with dope" LOL just had to say that.
In larger metal halide bulbs the arc gap is about two inches across. Even when you have a proper reflector the smallest focal point you are going to get is about a two inch diameter. All the reflector does is take most of the light available and concentrate it into one spot, about the size of the original arc gap. I actually used a huge reflector and 400W MH bulb (the large vareity) in my first design. It worked well but the projector was just to big overall. I think 400W provides plenty of brightness but your lcd's contrast is more important in my opinion.
was that phrased in a question? produce enough light for 16' ............................16 foot image you mean? No sad to say,wish but it wouldnt.
How's about these guys, I don't care about size, just quality of final image, it could be as large as a beer fridge for all I care 🙂
http://www.auroralighting.ca/lighting.html Canadian Dollars too yay.
http://www.auroralighting.ca/lighting.html Canadian Dollars too yay.
Me too.
I too have been seeking a solution to build a very high output homebrew projector. My goal was a 10' wide rear projected screen (I wanted to build a portable "tent" to take to computer shows to run videos on).
You can see my notes here: <BR>
http://wiki.757.org/doku.php?id=projects:lcd_overhead_projector
<BR>
I'm in the same boat that I don't care about size, and I don't care about power draw. My laser system eats 3 phase / 208vac @ 30 amps per leg and can still trip the breaker.
One lamp:
HMI 2500W/GS $299.00
6000
500 hours
240000 lumens
Arc Length: 14mm
The thing I'm running into is the ballasts for these wierd bulbs are hard to come by.
I too have been seeking a solution to build a very high output homebrew projector. My goal was a 10' wide rear projected screen (I wanted to build a portable "tent" to take to computer shows to run videos on).
You can see my notes here: <BR>
http://wiki.757.org/doku.php?id=projects:lcd_overhead_projector
<BR>
I'm in the same boat that I don't care about size, and I don't care about power draw. My laser system eats 3 phase / 208vac @ 30 amps per leg and can still trip the breaker.
One lamp:
HMI 2500W/GS $299.00
6000
500 hours
240000 lumens
Arc Length: 14mm
The thing I'm running into is the ballasts for these wierd bulbs are hard to come by.
A rear projector has significant picture problems at this time, due to the screen material.
Could you consider a ceiling-mounted front projector?
That 2.5kw bulb is overkill, IMO, especially noting that it's going to cost you probably a dollar an hour to run the thing, along with replacing it every <500 hours and cleanup when it bursts.
Could you consider a ceiling-mounted front projector?
That 2.5kw bulb is overkill, IMO, especially noting that it's going to cost you probably a dollar an hour to run the thing, along with replacing it every <500 hours and cleanup when it bursts.
Hmmm
Well I found real rear projection screen material via eBay. It's about $230 for enough to do a 10' (or was it 12') wide 16:9 ratio display.
For that application rear projection is best. However, it would be awesome to be able to do outdoor movies... invite friends over and what not. Except the bugs that the light source will attract 🙂
There is a 1500 watt version of the bulb as well, so that is an option if 2500 is way over the top.
My issues are:
#1, the ballast. Can I use the same type of ballast that is used to drive long arc 1500 watt MH lamps that are used for say, warehouse lighting? If not, the only ballasts are those from the photography world
#2, cooling. The LCD panel is going to be absorbing a ton of heat. Would it even be possible to cool a LCD panel? I figure a hot/cold mirror would definitly be used. The entire thing would be cooled by several high rpm blowers like those used on small frame argon lasers.
The output from the 400 watt projectors looks really nice, so I'm guessing 1500 would probably be enough.
My other train of thougt was to take a commercial DLP projector, and modify it to feed the light from a 1500 or 2500 watt bulb into it. These units are going to have good cooling already, so by forcing 30 times more air thru the thing, would that keep the optics cool enough?
Well I found real rear projection screen material via eBay. It's about $230 for enough to do a 10' (or was it 12') wide 16:9 ratio display.
For that application rear projection is best. However, it would be awesome to be able to do outdoor movies... invite friends over and what not. Except the bugs that the light source will attract 🙂
There is a 1500 watt version of the bulb as well, so that is an option if 2500 is way over the top.
My issues are:
#1, the ballast. Can I use the same type of ballast that is used to drive long arc 1500 watt MH lamps that are used for say, warehouse lighting? If not, the only ballasts are those from the photography world
#2, cooling. The LCD panel is going to be absorbing a ton of heat. Would it even be possible to cool a LCD panel? I figure a hot/cold mirror would definitly be used. The entire thing would be cooled by several high rpm blowers like those used on small frame argon lasers.
The output from the 400 watt projectors looks really nice, so I'm guessing 1500 would probably be enough.
My other train of thougt was to take a commercial DLP projector, and modify it to feed the light from a 1500 or 2500 watt bulb into it. These units are going to have good cooling already, so by forcing 30 times more air thru the thing, would that keep the optics cool enough?
My use
I should comment that my intended use for the rear projection setup is more trade shows / parties / outdoor type of use, not for an indoor home theater. I own a CRT projector, and am looking at building a 400 watt HID LCD projector for my office so I can leave computer data up on the wall without worrying about bulb life 🙂
I had the idea of using steel pipe and handrail couplings to build a semi portable "tent" that has the screen ont he front, and is covered on the other sides. A first surface mirror setup could be used to reduce the throw distance needed. Imagine a really large rear projection set.
I should comment that my intended use for the rear projection setup is more trade shows / parties / outdoor type of use, not for an indoor home theater. I own a CRT projector, and am looking at building a 400 watt HID LCD projector for my office so I can leave computer data up on the wall without worrying about bulb life 🙂
I had the idea of using steel pipe and handrail couplings to build a semi portable "tent" that has the screen ont he front, and is covered on the other sides. A first surface mirror setup could be used to reduce the throw distance needed. Imagine a really large rear projection set.
Idea: If you're unconcerned about size, you could use a large-arc bulb at half the focal length of a very large fresnel (1m pavement-burners you can buy at alltronics for ~$50-$100), and at the other end, after the rays have crossed, use a smaller fresnel to collimate it.
This would make the effective arc length that the lcd sees much less, at the expense of making your projector VERY big (At this point, we're talking a dresser-sized vertical setup with a mirror at the top).
Also, you could bend a precondensor fresnel slightly to correct for the fact that you're projecting a line instead of a point.
This would make the effective arc length that the lcd sees much less, at the expense of making your projector VERY big (At this point, we're talking a dresser-sized vertical setup with a mirror at the top).
Also, you could bend a precondensor fresnel slightly to correct for the fact that you're projecting a line instead of a point.
If the arc length is 2" long, when you use a fresnel that's 50" wide to project onto a 12" wide collector fresnel/LCD, you bring the effective arc length down to a little under 1/2".
You could also try some kind of very-close-to-the-bulb thick precondensor to bend the light enough that it crosses, which I THINK would be a pointsource - am I correct here?
You could also try some kind of very-close-to-the-bulb thick precondensor to bend the light enough that it crosses, which I THINK would be a pointsource - am I correct here?
That $300 2500 watt bulb had an arc length of 14mm ... that is a short arc lamp, correct?
Would there be problems (outside of all the heat issues) with using that bulb in a setup similiar to the normal 15" diag LCD / fresnel lens set?
12' wide/9' tall ? (4:3) using 1200 watt to 2500 watt light source. Should be very bright as well... 14mm arc length, 1500/2500 watt bulb?
There is a 1200 watt version of the lamp, used in followspots and such. Cheaper, at about $130 for 750 hours. 100vac, 1200 watt, 90CRI Haven't found the arc length of the bulb (HMI 1200W/GS)
Would there be problems (outside of all the heat issues) with using that bulb in a setup similiar to the normal 15" diag LCD / fresnel lens set?
12' wide/9' tall ? (4:3) using 1200 watt to 2500 watt light source. Should be very bright as well... 14mm arc length, 1500/2500 watt bulb?
There is a 1200 watt version of the lamp, used in followspots and such. Cheaper, at about $130 for 750 hours. 100vac, 1200 watt, 90CRI Haven't found the arc length of the bulb (HMI 1200W/GS)
In theory, yes...
I'm just sort of dismissing short-arc bulbs for my personal use because of the high UV output, the amount of focused forced air cooling needed, the replacement annoyance, and the short life/large cost.
I would judge 1.5kw to be more than adequate for a 12 ft screen, btw, especially if you use a short-arc bulb.
It's equivalent luminance(assuming equal lumens/watt) as using a 400 watt MH bulb on a 75" screen, which is just above the point where the screen becomes uncomfortably bright for some people.
I'm just sort of dismissing short-arc bulbs for my personal use because of the high UV output, the amount of focused forced air cooling needed, the replacement annoyance, and the short life/large cost.
I would judge 1.5kw to be more than adequate for a 12 ft screen, btw, especially if you use a short-arc bulb.
It's equivalent luminance(assuming equal lumens/watt) as using a 400 watt MH bulb on a 75" screen, which is just above the point where the screen becomes uncomfortably bright for some people.
Hmmm
Okay the 1200 watt version is more affordable (I edited my earlier post with more information). Brings the cost down to something like 33 cents per hour. I looked up a professional 10,000 lumens DLP unit and the replacement bulb is 3,300 euros... for 1000 hours! The projector is insanely expensive on the used market even.
So if I dump the UV/IR using a cold mirror (or hot mirrror), will that greatly reduce the issue of the LCD turning black from heat? The 1200 watt bulb info was talking about how unfortunately you still have to have some sort of fan to cool it. Doesn't sound like it is going to be that hard to cool. The harder part will be finding a ballast setup.
It would be awesome to be able to project 20' wide. For greater throw distance, does the triplett lens just have to come farther away from the output fresnel? I had anticipated using a design like the ones with the drawer slides, only perhaps using electric screwdriver guts and a threaded rod to add some motorization to the setup.
Okay the 1200 watt version is more affordable (I edited my earlier post with more information). Brings the cost down to something like 33 cents per hour. I looked up a professional 10,000 lumens DLP unit and the replacement bulb is 3,300 euros... for 1000 hours! The projector is insanely expensive on the used market even.
So if I dump the UV/IR using a cold mirror (or hot mirrror), will that greatly reduce the issue of the LCD turning black from heat? The 1200 watt bulb info was talking about how unfortunately you still have to have some sort of fan to cool it. Doesn't sound like it is going to be that hard to cool. The harder part will be finding a ballast setup.
It would be awesome to be able to project 20' wide. For greater throw distance, does the triplett lens just have to come farther away from the output fresnel? I had anticipated using a design like the ones with the drawer slides, only perhaps using electric screwdriver guts and a threaded rod to add some motorization to the setup.
For greater distances, you just need to move the physical projector back or forward. AFAICT that there's a point(a distance away from the fresnel) that the triplet is focused, and you need a varifocal triplet to have even a small amount of headroom with zooming.
I highly recommend that you check out the Lumenlab forums(You buy their guide / subscribe) - big repository of information on a workable design.
Have you thought about a reflector yet?
You DEFINITELY need some cooling in anything with a tenth that wattage, and hopefully you'd make it out of aluminum + steel. I'm thinking that for 1kw plus, a decent centrifugal blower is going to be required, with good air movement over the LCD as well as the bulb assembly and the mirror (If the mirror will even take that much heat). One of the things that scared me about the small arc bulbs was that their spec sheets generally REQUIRE a few ft/second of forced air cooling, and delivering that consistantly focused on the bulb is difficult.
edit: Reflector that MIGHT fit a BT56 bulb: 4.2quart Norpro: http://www.life-ease.com/gripbowls.html
I highly recommend that you check out the Lumenlab forums(You buy their guide / subscribe) - big repository of information on a workable design.
Have you thought about a reflector yet?
You DEFINITELY need some cooling in anything with a tenth that wattage, and hopefully you'd make it out of aluminum + steel. I'm thinking that for 1kw plus, a decent centrifugal blower is going to be required, with good air movement over the LCD as well as the bulb assembly and the mirror (If the mirror will even take that much heat). One of the things that scared me about the small arc bulbs was that their spec sheets generally REQUIRE a few ft/second of forced air cooling, and delivering that consistantly focused on the bulb is difficult.
edit: Reflector that MIGHT fit a BT56 bulb: 4.2quart Norpro: http://www.life-ease.com/gripbowls.html
Word of caution, my cheap (doallar store ladle) discoloured after a short period of time with my 500 watt halogen. May not be that big a problem as a 400 watt HQI likely has a much lower heat output.
Hmm
Okay, the reason i mentioned focus is I would figure the farther away from the screen the projector is, the more room for adjustment needed for the focus.
My next issue is this... Ballast for the lamp. I found this multitap magnetic ballast that delivers 1500 watts:
http://www.businesslights.com/product_info.php?cPath=31_244&products_id=55
Then there is the bulb:
http://www.bulbconnection.com/ViewItem/bcrw/itmid/429/oc/HMI 1200W/GS/item.html
The ballast is targeted towards a commercial MH lamp (think warehouse lights). I can't find a definitive answer on the proper ballast for use with the HQI lamp.
If those two will work together, then the only issue to really solve is one of heat.
I could probably use 4000cfm AC fans and a blower for the lamp house.
It HAS to be metal, there is a risk if the bulb pops that fragments could ignite material around it. I will probably try to make a lamphouse in the box, with aluminum pipe going to blower to suck off the hot air.
Okay, the reason i mentioned focus is I would figure the farther away from the screen the projector is, the more room for adjustment needed for the focus.
My next issue is this... Ballast for the lamp. I found this multitap magnetic ballast that delivers 1500 watts:
http://www.businesslights.com/product_info.php?cPath=31_244&products_id=55
Then there is the bulb:
http://www.bulbconnection.com/ViewItem/bcrw/itmid/429/oc/HMI 1200W/GS/item.html
The ballast is targeted towards a commercial MH lamp (think warehouse lights). I can't find a definitive answer on the proper ballast for use with the HQI lamp.
If those two will work together, then the only issue to really solve is one of heat.
I could probably use 4000cfm AC fans and a blower for the lamp house.
It HAS to be metal, there is a risk if the bulb pops that fragments could ignite material around it. I will probably try to make a lamphouse in the box, with aluminum pipe going to blower to suck off the hot air.
I'm thinking something quieter - a ~1 sone 100cfm (which nonetheless has a much, much higher capacity for moving air against pressure than a casefan) inline ventillation duct blower.
Maybe a reflector would be too hard to put together for this - matching the placement of <5mm areas you can't see in three dimensional space is going to be... difficult.
Biggun', the spoon discolored or the bulb? I linked a bowl that should be a solid steel hemisphere with a diameter of ~25cm.
Re the ballast, I'll look into it, but I doubt that a short arc lamp can be run off a ballast intended for a long arc lamp - the voltages just don't work out the same way over different distances.
Maybe a reflector would be too hard to put together for this - matching the placement of <5mm areas you can't see in three dimensional space is going to be... difficult.
Biggun', the spoon discolored or the bulb? I linked a bowl that should be a solid steel hemisphere with a diameter of ~25cm.
Re the ballast, I'll look into it, but I doubt that a short arc lamp can be run off a ballast intended for a long arc lamp - the voltages just don't work out the same way over different distances.
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