Forrest: Dichoric Bulbs
Hey Forrest,
I'm in the UK too, I found The Dichoric bulps in Maplin, you should check it out, they have a 75watt bulp, with a 13 degree beam, which might make it easier for you to focus the beam if you're using a small LCD
Also you might need to filter out some UV from the bulp, not sure though.
Hope your project goes well, I'd be interested to see how you do.
James
Hey Forrest,
I'm in the UK too, I found The Dichoric bulps in Maplin, you should check it out, they have a 75watt bulp, with a 13 degree beam, which might make it easier for you to focus the beam if you're using a small LCD
Also you might need to filter out some UV from the bulp, not sure though.
Hope your project goes well, I'd be interested to see how you do.
James
Hows the Playstation lcd?
http://www.ebgames.com/ebx/categories/products/product.asp?pf_id=203708
Just wondering if this is any good to use for videogames and tv/dvd etc...?.
Also anyone use this on already?
how easy is it to take it apart to use our own light source?
Thanks!
If i dont get that one im getting this one on ebay,
http://cgi.ebay.com/aw-cgi/eBayISAP...&showTutorial=0&ed=1014429946&indexURL=0&rd=1
http://www.ebgames.com/ebx/categories/products/product.asp?pf_id=203708
Just wondering if this is any good to use for videogames and tv/dvd etc...?.
Also anyone use this on already?
how easy is it to take it apart to use our own light source?
Thanks!
If i dont get that one im getting this one on ebay,
http://cgi.ebay.com/aw-cgi/eBayISAP...&showTutorial=0&ed=1014429946&indexURL=0&rd=1
Correction
Just letting everyone know that I also read a page today on the rad5 that claimed a 35ms response time. So- I'm not sure what the deal is. Bottom line: if you're going to buy a monitor, check out the different models and see what you like best. I saw a very nice samsung today that had a much better black than my KDS(bummer) for only $70 CDN more. I dunno.
I've been doing some experimenting with my low-res screen tonight since I'm scared to take apart my kds until I've gotten an ohp. Some pretty good results were acheived, but still nowhere near bright enough. My bulb claimed it was 11,000 lumens, but I'm not getting even 750 lumens out of the LCD. 🙁 One thing the bulb does have is heat. I was using a couple of page magnifier fresnels to concentrate the light, but decided that just moving the light closer to the LCD worked better(unfortunately after I melted a fresnel..).
Waiting for a osram catalog from a friend of mine- I need a new lightsource.
Just letting everyone know that I also read a page today on the rad5 that claimed a 35ms response time. So- I'm not sure what the deal is. Bottom line: if you're going to buy a monitor, check out the different models and see what you like best. I saw a very nice samsung today that had a much better black than my KDS(bummer) for only $70 CDN more. I dunno.
I've been doing some experimenting with my low-res screen tonight since I'm scared to take apart my kds until I've gotten an ohp. Some pretty good results were acheived, but still nowhere near bright enough. My bulb claimed it was 11,000 lumens, but I'm not getting even 750 lumens out of the LCD. 🙁 One thing the bulb does have is heat. I was using a couple of page magnifier fresnels to concentrate the light, but decided that just moving the light closer to the LCD worked better(unfortunately after I melted a fresnel..).
Waiting for a osram catalog from a friend of mine- I need a new lightsource.
LCD response time
I was looking at the response time of some lcd and they had a response time for the turn-on and the turn-off of the pixles so maybe that's the diff.
I was looking at the response time of some lcd and they had a response time for the turn-on and the turn-off of the pixles so maybe that's the diff.
Hows the playstation lcd and panel colors....
Hows the Playstation lcd?
http://www.ebgames.com/ebx/categori...sp?pf_id=203708
Just wondering if this is any good to use for videogames and tv/dvd etc...?.
Also anyone use this on already?
how easy is it to take it apart to use our own light source?
Thanks!
If i dont get that one im getting this one on ebay,
http://cgi.ebay.com/aw-cgi/eBayISAP...indexURL=0&rd=1
2nd) I dont know a thing about panels i need to know what color is the minimum we should buy. Like should it be 16.7million colors 1.4? I never see anythat are 16.7 million colors where are these good ones?
Thanks!
Hows the Playstation lcd?
http://www.ebgames.com/ebx/categori...sp?pf_id=203708
Just wondering if this is any good to use for videogames and tv/dvd etc...?.
Also anyone use this on already?
how easy is it to take it apart to use our own light source?
Thanks!
If i dont get that one im getting this one on ebay,
http://cgi.ebay.com/aw-cgi/eBayISAP...indexURL=0&rd=1
2nd) I dont know a thing about panels i need to know what color is the minimum we should buy. Like should it be 16.7million colors 1.4? I never see anythat are 16.7 million colors where are these good ones?
Thanks!
Some LCD light info
This page makes me wonder if there are some parts we may be missing. It claims light bulbs put out unpolarized light but that it needs proper polarization to shine through a LCD panel. The guy has some great design ideas and a Google search for "quarter-wave retarder" and "reflective polarizer" yeild plenty of sources for both parts and more reading. It could help greatly reduce the lumens needed to light up a LCD projector. Back to the old drawing board....
http://www.nasatech.com/Briefs/June01/NPO20824.html
This page makes me wonder if there are some parts we may be missing. It claims light bulbs put out unpolarized light but that it needs proper polarization to shine through a LCD panel. The guy has some great design ideas and a Google search for "quarter-wave retarder" and "reflective polarizer" yeild plenty of sources for both parts and more reading. It could help greatly reduce the lumens needed to light up a LCD projector. Back to the old drawing board....
http://www.nasatech.com/Briefs/June01/NPO20824.html
hi to all folks !
i have an excellent sharp xv-55 lcd proyector working great
but i notice that the lens & mirrors internally are dirty creating
more conrtasted effect on the image than usual.
i tried to dismendlit but its almost because it is a sealed plastic tunnel with the lcds / filters & mirrosr.
if anyone knows how to clean lens i will appreciate the info !
thanks
richt😕
i have an excellent sharp xv-55 lcd proyector working great
but i notice that the lens & mirrors internally are dirty creating
more conrtasted effect on the image than usual.
i tried to dismendlit but its almost because it is a sealed plastic tunnel with the lcds / filters & mirrosr.
if anyone knows how to clean lens i will appreciate the info !
thanks
richt😕
Hello people.
I'm going to give a rest to the diy-projector for now. I just spent $250 more on the Medium OHP cause the bulb actually wasn't busted, it was some starter chip or whatever. Well I have an spare bulb now anyway. The thing is quite cool, bright enough and my wall isn't big enough to fit the whole image in to it, I'll need to use another wall but for that I need projection screen which decent ones are like $800 around here so **** me. I saw some cheap ones too but I don't know if they are any good. I wonder how projection screen can be so expensive. More on prices: 15" Viewsonic costs $500 around here. Cheapest small LCD I could find (with low-res) was like $200. I was thinking of buying small LCD and making diy-thing from that but I don't think i'm going to do it for now.
I'm actually wondering now, how much does cost cheapest commercial projector in US or anywhere? Here it is like $3500. I happily enough happen to live in the one of the expensivest countries in the world.
I'll get happy with the ohp for now, I will be with you people in here anyway, if anyone gives a **** anyway🙂
I'm going to give a rest to the diy-projector for now. I just spent $250 more on the Medium OHP cause the bulb actually wasn't busted, it was some starter chip or whatever. Well I have an spare bulb now anyway. The thing is quite cool, bright enough and my wall isn't big enough to fit the whole image in to it, I'll need to use another wall but for that I need projection screen which decent ones are like $800 around here so **** me. I saw some cheap ones too but I don't know if they are any good. I wonder how projection screen can be so expensive. More on prices: 15" Viewsonic costs $500 around here. Cheapest small LCD I could find (with low-res) was like $200. I was thinking of buying small LCD and making diy-thing from that but I don't think i'm going to do it for now.
I'm actually wondering now, how much does cost cheapest commercial projector in US or anywhere? Here it is like $3500. I happily enough happen to live in the one of the expensivest countries in the world.
I'll get happy with the ohp for now, I will be with you people in here anyway, if anyone gives a **** anyway🙂
LEDs and such
hey guys, i mean i read a lot of the postings on this thread but not everything... but i saw that you all said that white leds are not bright enough. so i wondered if anyone ever thought about actually building three projectors, where one of them is just for one color. like have a led array, a mono lcd, a red (green/blue) filter and a prjection lens (plus the usual like fresnels/cold mirror blah blah). this way you get three times as much leds in the thing and thus more brightness... of course the alignment of the picture on the wall is something that is hard to automate, even tho it should be able to calculate the angles from the focus of the projector lenses, somehow. well, its just an idea, if anyone accidently stumbles upon some good ideas cause of this, inform me 🙂
Winti
hey guys, i mean i read a lot of the postings on this thread but not everything... but i saw that you all said that white leds are not bright enough. so i wondered if anyone ever thought about actually building three projectors, where one of them is just for one color. like have a led array, a mono lcd, a red (green/blue) filter and a prjection lens (plus the usual like fresnels/cold mirror blah blah). this way you get three times as much leds in the thing and thus more brightness... of course the alignment of the picture on the wall is something that is hard to automate, even tho it should be able to calculate the angles from the focus of the projector lenses, somehow. well, its just an idea, if anyone accidently stumbles upon some good ideas cause of this, inform me 🙂
Winti
Re: LEDs and such
The LED idea has been concluded that it is not feasible at this point.
1) too much work to do to hook up so many LEDs.
2) not bright enough until you spend $1200+ worth of LEDs.
3) brightness among LEDs are not uniform.
The point of going w/ LED route is to have cold and long lasting light source. I really think LOA is the way to go.
Wintifax said:
The LED idea has been concluded that it is not feasible at this point.
1) too much work to do to hook up so many LEDs.
2) not bright enough until you spend $1200+ worth of LEDs.
3) brightness among LEDs are not uniform.
The point of going w/ LED route is to have cold and long lasting light source. I really think LOA is the way to go.
Greetings from Scotland
Hello everyone,
Been away for a while, have got myself up to date with the forum and see some interesting stuff, Vince and Bitch taking a rest for instance.
Anyways, to Forrest and Jamesdlow, I got the dichroic bulbs from Maplin too, but found them to be pretty hot, but then I'm not used to the heat from a normal (not dichroic) halogen I suppose so I couldn't tell the difference.
Whereabouts in the UK are you guys? I'm in Scotland too Forrest. It's good to get some ideas on where to source parts outwith the US.
Cheers,
Chris.
Hello everyone,
Been away for a while, have got myself up to date with the forum and see some interesting stuff, Vince and Bitch taking a rest for instance.
Anyways, to Forrest and Jamesdlow, I got the dichroic bulbs from Maplin too, but found them to be pretty hot, but then I'm not used to the heat from a normal (not dichroic) halogen I suppose so I couldn't tell the difference.
Whereabouts in the UK are you guys? I'm in Scotland too Forrest. It's good to get some ideas on where to source parts outwith the US.
Cheers,
Chris.
Re: Some LCD light info
I wondered about this. Does anyone know any more about the need for polarizers etc. for TFT displays? When I pulled mine apart originally there were several thin sheets of translucent plastic between the glass LCD panel and the big plastic light pipe for the CFL backlight. At least one was just a fine diffuser, but I thought that one or more of them could be a polarising sheet. However the best performance I got out of the LCD in the projector is with NONE of these sheets in place. All they seem to do is cut down the brightness. I have to assume whatever necessary polarizers are actually integral to the glass panel and can't be removed.
On another note, I have been doing a bit of ray tracing work to get a better understanding of the optics involved, and I have to conclude that the closer to a point light source you have, the better contrast ratio you will achieve. With a wide source like a LOA light, you will get multiple light paths through the same pixel area on the LCD going through the projection lens and hitting the projection screen. This won't cut down the brightness, but it will wash out the image. I want to look a bit more into HID lighting for vehicles, I think they might get cheaper with time. I spotted a set of 100W 'HID' globes in a car dealer as a retrofit kit for older cars with H4 headlights. They were very cheap, and I asked the guy what else you needed to use them, presumeably starters and ballasts etc. and he said none. He said they were (and this is word for word, make of it what you will), "they are half way between true HID lights and halogen". That doesn't really make sense to me, but I want to look into it a bit more. They were 100W super white bulbs, packet of 2 for AUD$40, about US$20. Of course no specs on the box about lumen output or anything.
djimmah said:
I wondered about this. Does anyone know any more about the need for polarizers etc. for TFT displays? When I pulled mine apart originally there were several thin sheets of translucent plastic between the glass LCD panel and the big plastic light pipe for the CFL backlight. At least one was just a fine diffuser, but I thought that one or more of them could be a polarising sheet. However the best performance I got out of the LCD in the projector is with NONE of these sheets in place. All they seem to do is cut down the brightness. I have to assume whatever necessary polarizers are actually integral to the glass panel and can't be removed.
On another note, I have been doing a bit of ray tracing work to get a better understanding of the optics involved, and I have to conclude that the closer to a point light source you have, the better contrast ratio you will achieve. With a wide source like a LOA light, you will get multiple light paths through the same pixel area on the LCD going through the projection lens and hitting the projection screen. This won't cut down the brightness, but it will wash out the image. I want to look a bit more into HID lighting for vehicles, I think they might get cheaper with time. I spotted a set of 100W 'HID' globes in a car dealer as a retrofit kit for older cars with H4 headlights. They were very cheap, and I asked the guy what else you needed to use them, presumeably starters and ballasts etc. and he said none. He said they were (and this is word for word, make of it what you will), "they are half way between true HID lights and halogen". That doesn't really make sense to me, but I want to look into it a bit more. They were 100W super white bulbs, packet of 2 for AUD$40, about US$20. Of course no specs on the box about lumen output or anything.
I found some good info. If it hasn't been posted yet check it out
http://www.audiovisualizers.com/madlab/lcd_proj.htm
THESE ARE ALL PEOPLE WHO SUCCESFULY BUILT THEIR OWN PROJECTORS.
http://www.audiovisualizers.com/madlab/lcd_proj.htm
THESE ARE ALL PEOPLE WHO SUCCESFULY BUILT THEIR OWN PROJECTORS.
Polarized light
Muzzman,
I have two sheets from my laptop display too, and they appear to refract light differently when aligned the same. so I think that they are polarizing reflectors. They are too flimsy too be useful due to needing a perfectly flat surface to reflect back to a mirror behind the lightsource. I'm scared to use a piece of glass to mount them as I don't know if this would refract the light improperly. I found several links off Google that said the same thing as the articl I posted, so it's not just a theroy. The reason they seem to reduce your light when you use them is because they only allow light that is polarized correctly to pass thru. You need to direct the deflected light back to the reflector of your light source to be used again. The purpose of the wave retarder is to shift the polarity of the deflected light so that it passes thru the polarized screen on the second try (or third or fourth, etc). It also seems that the lcd panel is reflecting unpolarized light instead of letting it pass. If you can get all your light properly polarized it should all pass and increase the brightness alot.
Whew! too many big words for us two finger typists....
Muzzman,
I have two sheets from my laptop display too, and they appear to refract light differently when aligned the same. so I think that they are polarizing reflectors. They are too flimsy too be useful due to needing a perfectly flat surface to reflect back to a mirror behind the lightsource. I'm scared to use a piece of glass to mount them as I don't know if this would refract the light improperly. I found several links off Google that said the same thing as the articl I posted, so it's not just a theroy. The reason they seem to reduce your light when you use them is because they only allow light that is polarized correctly to pass thru. You need to direct the deflected light back to the reflector of your light source to be used again. The purpose of the wave retarder is to shift the polarity of the deflected light so that it passes thru the polarized screen on the second try (or third or fourth, etc). It also seems that the lcd panel is reflecting unpolarized light instead of letting it pass. If you can get all your light properly polarized it should all pass and increase the brightness alot.
Whew! too many big words for us two finger typists....
Thanks djimmah, I will dig out the sheets I have and do a few experiments. Would certainly be pretty cool if we didn't have to use 10000+ lumen sources...
btw all, I have finally posted some pictures of my current setup and a few result photos of the screen at http://www.free2air.com.au/~mjcox
The photos of the image on the screen are really dissappointing, I had terrible trouble getting any recognisable photos at all from the borrowed digital camera I was using. Only after stuffing around with the white balance and exposure settings on the camera did I get anything, and the photos really don't do the results of the projector justice - they seem to be fuzzier than reality.
btw all, I have finally posted some pictures of my current setup and a few result photos of the screen at http://www.free2air.com.au/~mjcox
The photos of the image on the screen are really dissappointing, I had terrible trouble getting any recognisable photos at all from the borrowed digital camera I was using. Only after stuffing around with the white balance and exposure settings on the camera did I get anything, and the photos really don't do the results of the projector justice - they seem to be fuzzier than reality.
Small projector
Howdy, folks. I've been lurking here for a little while and have been very impressed with what I've seen.
I want to build a very small-scale projector for a very specialized application. This would be for my arcade cabinet... what I want to do is rig a rear-projection system in the marquee area so it would display the actual marquee of the game being played.
The dimensions of the marquee are about 26" wide by 8" high, so as you can see, I have no need for a powerful system able to display a ten-foot picture like others are building here. Space is a constraint... the area for mounting the projection system is not so big. Cost is also a primary concern.
I have a 2.5" LCD TV that I'm thinking of dismantling for the project... it supports composite video in, so I could use a second video card with TV out in my arcade cabinet's computer to drive it. The resolution might be insufficient, though.
Can anyone offer any advice for how I would build such a thing? The tight space constraints will also, I should think, present focusing difficulties... as the entire system will be sealed, it will be very difficult to adjust the focal length after it's installed, meaning 1) I need a way to prototype the system and get the focus just right before installing, and 2) it needs to be very sturdy, so jars to the cabinet will not disrupt the focus.
General consensus here seems to be that LEDs do not provide a practical or cost-effective lighting system for a normal projector... but how about for a scaled-down project such as mine? What exactly is an LOA and would that be a better lighting solution? Do I need lenses both in front of and behind the LCD, or will a single lens suffice? Any ideas for a good mounting for the lens? And where's a good source for Fresnel lenses, anyway? Again, cost is a constraint, and I don't want to buy an overhead projector just for the lens. An overhead projector lens would probably be too big, anyway.
What about the projection surface? I was thinking paper-coated Lexan, or possibly Lexan with a light coat of white paint... should that work?
Thanks in advance for any advice anyone can offer.
Howdy, folks. I've been lurking here for a little while and have been very impressed with what I've seen.
I want to build a very small-scale projector for a very specialized application. This would be for my arcade cabinet... what I want to do is rig a rear-projection system in the marquee area so it would display the actual marquee of the game being played.
The dimensions of the marquee are about 26" wide by 8" high, so as you can see, I have no need for a powerful system able to display a ten-foot picture like others are building here. Space is a constraint... the area for mounting the projection system is not so big. Cost is also a primary concern.
I have a 2.5" LCD TV that I'm thinking of dismantling for the project... it supports composite video in, so I could use a second video card with TV out in my arcade cabinet's computer to drive it. The resolution might be insufficient, though.
Can anyone offer any advice for how I would build such a thing? The tight space constraints will also, I should think, present focusing difficulties... as the entire system will be sealed, it will be very difficult to adjust the focal length after it's installed, meaning 1) I need a way to prototype the system and get the focus just right before installing, and 2) it needs to be very sturdy, so jars to the cabinet will not disrupt the focus.
General consensus here seems to be that LEDs do not provide a practical or cost-effective lighting system for a normal projector... but how about for a scaled-down project such as mine? What exactly is an LOA and would that be a better lighting solution? Do I need lenses both in front of and behind the LCD, or will a single lens suffice? Any ideas for a good mounting for the lens? And where's a good source for Fresnel lenses, anyway? Again, cost is a constraint, and I don't want to buy an overhead projector just for the lens. An overhead projector lens would probably be too big, anyway.
What about the projection surface? I was thinking paper-coated Lexan, or possibly Lexan with a light coat of white paint... should that work?
Thanks in advance for any advice anyone can offer.
MuzzMan
I'm probably just being dense, but what are you using the Composite to RGB splitter circuit for in your design?
Thanx
😀
I'm probably just being dense, but what are you using the Composite to RGB splitter circuit for in your design?
Thanx
😀
RGB out
Just in case this inspires anyone, the Playstation 2 has RGB output on it as well as composite video.
If anybody has any information on RGB signals I would be really grateful if they could send it my way; do they need a separate sync signal to work? What sorts of voltages are they and what do the waveforms look like? 😕
Believe it or not, this stuff is harder to find on the net than I thought. Or maybe I'm just being blonde 🙄
Someone help me pleeease!!!
Just in case this inspires anyone, the Playstation 2 has RGB output on it as well as composite video.
If anybody has any information on RGB signals I would be really grateful if they could send it my way; do they need a separate sync signal to work? What sorts of voltages are they and what do the waveforms look like? 😕
Believe it or not, this stuff is harder to find on the net than I thought. Or maybe I'm just being blonde 🙄
Someone help me pleeease!!!
I just got Lucky!!!!
I was in a server clustering class today and when I got out, sitting in a trash pile, were 2 Sharp- SharpVision projectors w/ a sticker marked "trash". I grabbed both of them, but another guy I work w/ asked me what they were and I told him and I asked if he wanted one so I gave the dude one. They are the same. I don't know if it works, but we'll see. I suspect they are 640x480 resolution. I will at least have one around to gut if it doesn't work.
Vince 😀 😀
I was in a server clustering class today and when I got out, sitting in a trash pile, were 2 Sharp- SharpVision projectors w/ a sticker marked "trash". I grabbed both of them, but another guy I work w/ asked me what they were and I told him and I asked if he wanted one so I gave the dude one. They are the same. I don't know if it works, but we'll see. I suspect they are 640x480 resolution. I will at least have one around to gut if it doesn't work.
Vince 😀 😀
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