For all who wanna know something about the problems with large sized bulbs here my quick poor drawing. Dimensions are not geometical correct. You can see the rays which come from off axis don't reach the projection lens. It would be the same if a point light source was shifted to the outer region !
xblocker
xblocker
Attachments
xblocker
I get it now; create a point source with an elliptical reflector. I'm off to ebay to see if I can get a Newtonian telescope that can be fed the light from a MH lamp.
I get it now; create a point source with an elliptical reflector. I'm off to ebay to see if I can get a Newtonian telescope that can be fed the light from a MH lamp.
A commercial solution to "big light source" problem?
Looks like these guys have it all figured out. Don't know if they have any product for sale yet.
http://wavien.com/images/wavien_whitepaper.pdf
Looks like these guys have it all figured out. Don't know if they have any product for sale yet.
http://wavien.com/images/wavien_whitepaper.pdf
Reflectors and such: SIZE MATTERS!
Its kinda funny that attention is finally being paid to reflectors. This has been one of my concerns all along... But why re-invent the wheel? I'm sure all of you have seen the insides of OHPs by know, they are all (all the ones I've seen) based on small bulbs with small reflectors.
---->Several people have tried to drive this following point home now, but pretty much ignored: You are not going to get focused light rays from a field of light! It doesn't matter if its from a light array or a perfect elliptical reflector. The whole point is to have a small light source is to let the frensel do its job. The only way to do this is to get a small enough bulb so that you can use a small enough reflector (or ditch the reflector all together and make do with ~40% output or so). By small, this is all relative, but it has to do with the relative size of the frensel. Remember the frensel the the key to all of this, so you have to operate around its parameters!
To sum it all up:
1) find a small enough bulb to use a small reflector with. It does NOT matter much if the reflector is a perfect shape or not, as long as its small. (functionality wise, of course the % light effecency improves if shape is good..)
2) If you can't find a small bulb, just use the bulb then, don't use a large reflector!
Now then, barring any major errors with my post, holy grail now is for a cheap SMALL MH bulb....
Its kinda funny that attention is finally being paid to reflectors. This has been one of my concerns all along... But why re-invent the wheel? I'm sure all of you have seen the insides of OHPs by know, they are all (all the ones I've seen) based on small bulbs with small reflectors.
---->Several people have tried to drive this following point home now, but pretty much ignored: You are not going to get focused light rays from a field of light! It doesn't matter if its from a light array or a perfect elliptical reflector. The whole point is to have a small light source is to let the frensel do its job. The only way to do this is to get a small enough bulb so that you can use a small enough reflector (or ditch the reflector all together and make do with ~40% output or so). By small, this is all relative, but it has to do with the relative size of the frensel. Remember the frensel the the key to all of this, so you have to operate around its parameters!
To sum it all up:
1) find a small enough bulb to use a small reflector with. It does NOT matter much if the reflector is a perfect shape or not, as long as its small. (functionality wise, of course the % light effecency improves if shape is good..)
2) If you can't find a small bulb, just use the bulb then, don't use a large reflector!
Now then, barring any major errors with my post, holy grail now is for a cheap SMALL MH bulb....
Anyone consider a polarizing lense?
http://www.edmundoptics.com/IOD/DisplayProduct.cfm?Productid=1912
http://www.edmundoptics.com/IOD/DisplayProduct.cfm?Productid=1912
Ideas
Well idea #1 a reflector like said earlier get a rubber ball "About 8 inches in diameter" at the super market and spread fiber bondo on just under half of the ball. Most large citys have places where you can get stuff chrome plated. That would make a very reflective surface. now you got a nice reflector.
#2 MV and MH bulbs have 2 bulbs the arc tube and the outer protective bulb the outer bulb is way to huge the mess with so bust it! dont worry your light will still work but i sugest only running your bulb for 3/4 of its rated life because sometimes when these bulbs get old the arc tube explodes thats the reason for the outer bulb, oh yea DONT TOUCH the arc tube the oils on your fingers can cause it to shatter when it gets hot.
#3 go get a lens flat on one side convex on the other same size as the reflector that you made i sugest about 6" across place the arc tube in the middle of the reflector and convex lens the convex will help distribute the light evenly then point it through your 2 frensel lenses to your lcd.
This is how the high dollar OHP work but they use much smaller bulb,refelector,lens.
Well idea #1 a reflector like said earlier get a rubber ball "About 8 inches in diameter" at the super market and spread fiber bondo on just under half of the ball. Most large citys have places where you can get stuff chrome plated. That would make a very reflective surface. now you got a nice reflector.
#2 MV and MH bulbs have 2 bulbs the arc tube and the outer protective bulb the outer bulb is way to huge the mess with so bust it! dont worry your light will still work but i sugest only running your bulb for 3/4 of its rated life because sometimes when these bulbs get old the arc tube explodes thats the reason for the outer bulb, oh yea DONT TOUCH the arc tube the oils on your fingers can cause it to shatter when it gets hot.
#3 go get a lens flat on one side convex on the other same size as the reflector that you made i sugest about 6" across place the arc tube in the middle of the reflector and convex lens the convex will help distribute the light evenly then point it through your 2 frensel lenses to your lcd.
This is how the high dollar OHP work but they use much smaller bulb,refelector,lens.
Jam!! VGA adapter
For anyone who thought about getting one of these things from ebay to add video-in to the lcd panel, I just received mine today. I paid 35.00 for it, hooked it up today. It works with my LCD panel, a proxima ovation 810. It has a VGA loop through, so you can keep it connected to your panel and computer, and it has 3 preset color configurations. I think between these and the color controls on the panel itsaelf, finding the perfect color should not be hard. The colors looked correct out of the box on my CRT monitor, but the LCD screens is off-color until it is tweaked. It displays NTSC at 60Hz vertical refresh and PAL at 50Hz, and requires a horizontal frequency of 30-31.5kHz. I was worried it might not work with my panel, because my panel does not work with the VGA card (RADEON VE) in my computer. I have to use my notebook to run the panel, and of course my DVD drive is in my desktop.
On a side note: I used the panel with the MV light to test the JAM, and it seems I gave up too quickly on the MV. After letting it run for like 10 minutes, The light got much brighter and the bluish tint all but went away. I have not had a chance to test it in the dark yet, I work third shift and woke up late for work.
Third: Looking at this light hurts your eyes. There is a lot of UV given off by MV, my plan is to use the glass from the $9 halogen light before the panel, it is a UV filter.
I also have some ideas for reflecting the MV that i want to try, any success will be shared.
For anyone who thought about getting one of these things from ebay to add video-in to the lcd panel, I just received mine today. I paid 35.00 for it, hooked it up today. It works with my LCD panel, a proxima ovation 810. It has a VGA loop through, so you can keep it connected to your panel and computer, and it has 3 preset color configurations. I think between these and the color controls on the panel itsaelf, finding the perfect color should not be hard. The colors looked correct out of the box on my CRT monitor, but the LCD screens is off-color until it is tweaked. It displays NTSC at 60Hz vertical refresh and PAL at 50Hz, and requires a horizontal frequency of 30-31.5kHz. I was worried it might not work with my panel, because my panel does not work with the VGA card (RADEON VE) in my computer. I have to use my notebook to run the panel, and of course my DVD drive is in my desktop.
On a side note: I used the panel with the MV light to test the JAM, and it seems I gave up too quickly on the MV. After letting it run for like 10 minutes, The light got much brighter and the bluish tint all but went away. I have not had a chance to test it in the dark yet, I work third shift and woke up late for work.
Third: Looking at this light hurts your eyes. There is a lot of UV given off by MV, my plan is to use the glass from the $9 halogen light before the panel, it is a UV filter.
I also have some ideas for reflecting the MV that i want to try, any success will be shared.
REFLECTOR
hi all,
this is the easies way to make elliptical reflector,
no need complicated calculation, just draw it!
With this type of reflector, you no longer need fresnel panel to converge light!
I can't explain the theory due of my poor English language, but I hope my drawing can explain clearly.
Fender4, maybe this is the answer of your reflector problem.
reflector
BTW, I add some "false input entry warning" in my projector diagram & calculation, making it more easy to play.
lcd projector diagram & calculation
see you.
hi all,
this is the easies way to make elliptical reflector,
no need complicated calculation, just draw it!
With this type of reflector, you no longer need fresnel panel to converge light!
I can't explain the theory due of my poor English language, but I hope my drawing can explain clearly.
Fender4, maybe this is the answer of your reflector problem.
reflector
BTW, I add some "false input entry warning" in my projector diagram & calculation, making it more easy to play.
lcd projector diagram & calculation
see you.
A light source of 6 million candlepower,
75 million lumens
"Helicopter/Military Searchlight"
Supplies enough light from 5 Kilometres away to read a newspaper. An incredible 6 million candlepower. Servo controlled beam spread. 1 1/4 hours continuous use. Utilises a short arc Xenon bulb. Designed for Military search and rescue missions.
Size: 180 x 275 x 146mm
Weight: 1.45 Kg. (Searchlight) 2.45 Kg. (Battery Pack)
Power: 12v. DC
75 million lumens
"Helicopter/Military Searchlight"
Supplies enough light from 5 Kilometres away to read a newspaper. An incredible 6 million candlepower. Servo controlled beam spread. 1 1/4 hours continuous use. Utilises a short arc Xenon bulb. Designed for Military search and rescue missions.
Size: 180 x 275 x 146mm
Weight: 1.45 Kg. (Searchlight) 2.45 Kg. (Battery Pack)
Power: 12v. DC
Attachments
Geez, do you know the price of that thing?
$1,895.00 !!! damn
I also saw site where they produced 30,000 lumens using a 15W bulb (good reflector)
Here is another light source..$59.95
"Twin Bulb - 3 Million Candlepower Spotlight"
For the ultimate in handheld spotlights it is really tough to beat this unit. It is very well balanced but you need a reasonably strong arm or use the included shoulder strap. You can switch from one or two 100 watt halogen bulbs for maximum
illumination. It also has a 4 watt area light that will run for up to 15 hours. Mobile charger and power cords, plus AC charger cord included. 6 Amp/12Volt battery. Keep this device away from children.
Weight:7lbs. Size: 7-3/4" W x 12-1/4" H x 7-1/4" D.
gav...point noted..😀
$1,895.00 !!! damn
I also saw site where they produced 30,000 lumens using a 15W bulb (good reflector)
Here is another light source..$59.95
"Twin Bulb - 3 Million Candlepower Spotlight"
For the ultimate in handheld spotlights it is really tough to beat this unit. It is very well balanced but you need a reasonably strong arm or use the included shoulder strap. You can switch from one or two 100 watt halogen bulbs for maximum
illumination. It also has a 4 watt area light that will run for up to 15 hours. Mobile charger and power cords, plus AC charger cord included. 6 Amp/12Volt battery. Keep this device away from children.
Weight:7lbs. Size: 7-3/4" W x 12-1/4" H x 7-1/4" D.
gav...point noted..😀
Attachments
hello ravide
We have already discussed these handheld spotlights you are posting about a few pages back.
We have also already discussed candlepower, and how it is not significant to the brightness of a light -- but rather the intensity of the beam produced. Candlepower ratings are VERY misleading. candlepower is merely the intensity of a light at a certain point. If you take a 100W halogen bulb, and put it on a reflector, the candlepower of the narrow beam produced is much, much more intense than if you took that same exact 100W bulb, and put it in a glass sphere, and measured the intensity of the light at a certain point outside the sphere.
This Mean Spherical Candle Power (MSCP) is the important number, and, THAT number is almost NEVER given on these "2 or 3,000,000 candlepower spotlights." If you had the MSCP number of the light, then, you would be able to take it, and convert it to lumens. What you CAN'T do, is take the false 3,000,000 candlepower number and convert it to lumens. That would be 37,000,000 lumens -- and we all know that a 100W halogen will probably produce at MAXIMUM 4,000 lumens (and thats being very generous)
I've seen the 2,000,000 candlepower light made by the same company that makes that 3,000,000 one at K-Mart, and, I was actually thinking about picking it up for $34.99, since, I would at least be able to use it for testing, and, also, the reflector in it is probably really cool. Its 6" diameter, and has one 100W Quartz Halogen bulb I think (burns whiter than regular halogens)
See this PDF for candlepower reference:
http://www.caves.org.uk/led/foot1.pdf
We have already discussed these handheld spotlights you are posting about a few pages back.
We have also already discussed candlepower, and how it is not significant to the brightness of a light -- but rather the intensity of the beam produced. Candlepower ratings are VERY misleading. candlepower is merely the intensity of a light at a certain point. If you take a 100W halogen bulb, and put it on a reflector, the candlepower of the narrow beam produced is much, much more intense than if you took that same exact 100W bulb, and put it in a glass sphere, and measured the intensity of the light at a certain point outside the sphere.
This Mean Spherical Candle Power (MSCP) is the important number, and, THAT number is almost NEVER given on these "2 or 3,000,000 candlepower spotlights." If you had the MSCP number of the light, then, you would be able to take it, and convert it to lumens. What you CAN'T do, is take the false 3,000,000 candlepower number and convert it to lumens. That would be 37,000,000 lumens -- and we all know that a 100W halogen will probably produce at MAXIMUM 4,000 lumens (and thats being very generous)
I've seen the 2,000,000 candlepower light made by the same company that makes that 3,000,000 one at K-Mart, and, I was actually thinking about picking it up for $34.99, since, I would at least be able to use it for testing, and, also, the reflector in it is probably really cool. Its 6" diameter, and has one 100W Quartz Halogen bulb I think (burns whiter than regular halogens)
See this PDF for candlepower reference:
http://www.caves.org.uk/led/foot1.pdf
Hi undream,
is there any other way to measure the light output? How can one verify the light output claimed to be 3 million candlepower ?
Are these kind of spotlights a viable option for a light source?
I guess it should be a good option since the light is visible for 5 km and it has minimum dispersion
..or am i wrong?
is there any other way to measure the light output? How can one verify the light output claimed to be 3 million candlepower ?
Are these kind of spotlights a viable option for a light source?
I guess it should be a good option since the light is visible for 5 km and it has minimum dispersion
..or am i wrong?
really no way of measuring it. It does interest me a little though.
I really think it might be a more viable solution than trying to reflect a big bulky 7000lumen MV lamp with homemade reflectors. Even if it is 3000 or 3500 lumens -- It will be efficiently used light, all going to the right place. Now that I think about it more, I might go out and buy that 2mil cp spotlight at Kmart when I get back to the States (I'm on my honeymoon in Barbados right now, last port of call on our cruise, gotta love data jacks in our room, laptopers dream!)
Cya!
I really think it might be a more viable solution than trying to reflect a big bulky 7000lumen MV lamp with homemade reflectors. Even if it is 3000 or 3500 lumens -- It will be efficiently used light, all going to the right place. Now that I think about it more, I might go out and buy that 2mil cp spotlight at Kmart when I get back to the States (I'm on my honeymoon in Barbados right now, last port of call on our cruise, gotta love data jacks in our room, laptopers dream!)
Cya!
That's what i thought...but i can't locate one of these here in UK...the main thing that interests me is the reflector on those lights....should be pretty damn impresive if it can project a light path for 2 miles (at least that is what they claim)..
anyway enjoy yourself Undream...and keep us posted
cheers mate🙂
anyway enjoy yourself Undream...and keep us posted
cheers mate🙂
ENX lights?
anyone think maybe use the ENX lights that they use in overheads? Can get the 400w bulbs for cheap , they are compact, and even come with their own reflectors (parabolic?). Maybe get one of those, put a PCX lense infront of it to spread it for the fresnel?
They are all 82V though..... dont know how exactly to power them. Is there an 82V power supply or ballast for these lights?
Jay
anyone think maybe use the ENX lights that they use in overheads? Can get the 400w bulbs for cheap , they are compact, and even come with their own reflectors (parabolic?). Maybe get one of those, put a PCX lense infront of it to spread it for the fresnel?
They are all 82V though..... dont know how exactly to power them. Is there an 82V power supply or ballast for these lights?
Jay
Well, I feel Like an idiot. The answer to reflecting my MV light has been staring me in the face every time I get ready to drag myself to work. I took a couple of those big 34oz Coffee cans, cut them down the seam, and bent them into a parabola. Right now I am only using two, stacked on top of each other, making the bend in the cans spread horizontally. These things are almost like chrome on the inside, so it reflects nicely, and since it is not a mirror-like reflection, the hot spot from the MV filament is eliminated.. If you criss-cross them and fill in the corners, you could have a decent full reflector. Combined with the fresnal on the back of the lcd, it reflects light a lot better than the reflector that came with the setup. The top of the projected image was a little dim, so i cut up one of the smaller coffee cans (11.5 oz), flattened 2/3, and bent the rest appropriatly, and laid it on the bottom of the box(lcd is mounted upside down to correct for the lens). This gave the top of the image the needed light. Now I cannot wait for my new 250-watt MH setup. (thanks for that link JJanisnew!!). By the way the shipping on those MH yard lights is $30 to my address in NY, so they are hefty.
Still messing with reflectors during study breaks...not much progress, but I will post when I get some results.
Gunawan,
Thanks or the good tips on your webpage! That should come in handy.
jvisaria,
You might want to try the DYS bulbs. They are 600watts, and (I might be wrong on this) I think they run on 120v AC. Anything else would require a power supply or at least a transformer. I know they can be found cheap, so they would be great to mess with. Probably put out heaps of heat, though.
Good luck everybody.
-f4
Gunawan,
Thanks or the good tips on your webpage! That should come in handy.
jvisaria,
You might want to try the DYS bulbs. They are 600watts, and (I might be wrong on this) I think they run on 120v AC. Anything else would require a power supply or at least a transformer. I know they can be found cheap, so they would be great to mess with. Probably put out heaps of heat, though.
Good luck everybody.
-f4
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