lol, gmshroll
hey soje, good to have you here.
with the LED's, the main two problems at the moment with them are; you have to hook up alot at the moment to get enough brightness, and also how the LED's actrually produce the white light, and the way they are doing it now does not produce an even colour spectrum, it just looks white to the human eye, but when you shine it through an LCD panel this is evident as some colours are not produced properly. When LED's are making alot more light and the light is even throughout the colour spectrum I think it will be very worthwhile to look into.
I have a Q. for you... the LCD's used in the projectors, I know the majority use a 3 LCD configuration with Red, Blue, Green. But libht loss throught the LCD... do you guys have the same problems as the guys in this forum? they are speaking of 90% light loss through the LCD panel, or do you have special ones that are made with projection in mind? Also DLP projectors... seing they reflect the light... is there much light loss from them? I imagine not.
thanks for any questions answered...
Reguards, Andrew
hey soje, good to have you here.
with the LED's, the main two problems at the moment with them are; you have to hook up alot at the moment to get enough brightness, and also how the LED's actrually produce the white light, and the way they are doing it now does not produce an even colour spectrum, it just looks white to the human eye, but when you shine it through an LCD panel this is evident as some colours are not produced properly. When LED's are making alot more light and the light is even throughout the colour spectrum I think it will be very worthwhile to look into.
I have a Q. for you... the LCD's used in the projectors, I know the majority use a 3 LCD configuration with Red, Blue, Green. But libht loss throught the LCD... do you guys have the same problems as the guys in this forum? they are speaking of 90% light loss through the LCD panel, or do you have special ones that are made with projection in mind? Also DLP projectors... seing they reflect the light... is there much light loss from them? I imagine not.
thanks for any questions answered...
Reguards, Andrew
Just what we need, an expert. Can you tell us what area you work in?
The LED idea is still on my wish list. But I think it will be a couple of years til they are strong enough and more effecient to run as a source of light for projectors.
I have a cluster of 48 with 5600 miro candals each or 5.6 mC each. It's bright, but looses force through the LCD.
The guys have a bunch of different ideas and they are starting to come together.
Vince
The LED idea is still on my wish list. But I think it will be a couple of years til they are strong enough and more effecient to run as a source of light for projectors.
I have a cluster of 48 with 5600 miro candals each or 5.6 mC each. It's bright, but looses force through the LCD.
The guys have a bunch of different ideas and they are starting to come together.
Vince
To All,
Ok I understand now that there are many curious people out there.
As I wrote in my first post, I decide what to answere. I you don't get an answere, you take a hint. OK.
Sorry Graham.
Andrew,
Yes you loose a lot of light. Not shur about the %. It varies with the resolution and the size of the panels.
In ex. 1.3" xga has a better throughput than 0.7" xga
So far there are 3 panels in use 1 for each color; red, green and blue.
Dividing the light into three different directions and let it go throug different colorglasses absorbs much light. And the engine itself does too.
Also new LCD technique makes it easier to make panels brighter.
Yes the panels are specially made for projectors and/or projection.
Imagine a panel that are 0.7" and has XGA (1024 x 768) resolution. You need a lot of light.
DLP's reflect the light, thats right. DLP projectors have much of the same light-treatments ( sorry no better word for it, I come from Norway) as LCD does, the difference is the light-wheel in DLP's and the color-glasses and LCD's in LCD-projectors.
Sorry, have to go. Will answere more later on.
Regards, Sondre
Ok I understand now that there are many curious people out there.
As I wrote in my first post, I decide what to answere. I you don't get an answere, you take a hint. OK.
Sorry Graham.
Andrew,
Yes you loose a lot of light. Not shur about the %. It varies with the resolution and the size of the panels.
In ex. 1.3" xga has a better throughput than 0.7" xga
So far there are 3 panels in use 1 for each color; red, green and blue.
Dividing the light into three different directions and let it go throug different colorglasses absorbs much light. And the engine itself does too.
Also new LCD technique makes it easier to make panels brighter.
Yes the panels are specially made for projectors and/or projection.
Imagine a panel that are 0.7" and has XGA (1024 x 768) resolution. You need a lot of light.
DLP's reflect the light, thats right. DLP projectors have much of the same light-treatments ( sorry no better word for it, I come from Norway) as LCD does, the difference is the light-wheel in DLP's and the color-glasses and LCD's in LCD-projectors.
Sorry, have to go. Will answere more later on.
Regards, Sondre
Has anyone seen one of these? I'd like to try an opaque projection scheme with it.
http://www.idg.net/idgns/2000/04/25/SamsungDevelopsReflectiveLCDForCell.shtml
http://www.idg.net/idgns/2000/04/25/SamsungDevelopsReflectiveLCDForCell.shtml
Hello again to all of you!
Vince, my area is electronics(development). I haven't been long in this game, so I'm hardly an expert. YET. Been here for five months, still learning but allready learned a lot. Trying to learn some of the optics too.
Iokost, this seem to be something to come. Reflective LCD's. The size of this particular LCD isn't what you would want in a projector. 720x240 pixels gives 3:1. Widescreen is 16:9 or 1.777....:1, and superwide is 2.35:1. You need a lot of scaling forcing you not to use a alot of the panels. In practice this will give you a grey frame on the side of the picture. But if there is a LCD with 16:9 or 2.35:1 we are talking business.
But as Vince are constantly thinking about, invention. We shouldn't be surprised if the widescreen get's wider in the years to come. I guess this is an invitation for George Lucas.
Flagre, du trenger ikke skrive på engelsk til meg.
In english for everyone that don't understand norwegian: Flagre, you don't have to write in english to me. Where do you go to school Flagre? And what area of interest?
I apologize to anyone that hoped I was an expert, wich I'm not.
Sondre
Vince, my area is electronics(development). I haven't been long in this game, so I'm hardly an expert. YET. Been here for five months, still learning but allready learned a lot. Trying to learn some of the optics too.
Iokost, this seem to be something to come. Reflective LCD's. The size of this particular LCD isn't what you would want in a projector. 720x240 pixels gives 3:1. Widescreen is 16:9 or 1.777....:1, and superwide is 2.35:1. You need a lot of scaling forcing you not to use a alot of the panels. In practice this will give you a grey frame on the side of the picture. But if there is a LCD with 16:9 or 2.35:1 we are talking business.
But as Vince are constantly thinking about, invention. We shouldn't be surprised if the widescreen get's wider in the years to come. I guess this is an invitation for George Lucas.
Flagre, du trenger ikke skrive på engelsk til meg.
In english for everyone that don't understand norwegian: Flagre, you don't have to write in english to me.
Where do you go to school Flagre? And what area of interest?I apologize to anyone that hoped I was an expert, wich I'm not.
Sondre
Forrest,
Dichrotic reflectors- do you need to know what they are or where to get them?
They absorb all light except one color, the color that is reflected. COuld be a mirror or a lense, I believe.
www.edmundoptics.com sells them.
soje, ok, at least you are in the business...
Vince
Dichrotic reflectors- do you need to know what they are or where to get them?
They absorb all light except one color, the color that is reflected. COuld be a mirror or a lense, I believe.
www.edmundoptics.com sells them.
soje, ok, at least you are in the business...
Vince
Rear Projection Folded Optics
I have found a front surface mirror at a local glass shop. It is 22" X 32" for $35.00 not to bad a price. This should be big enough to fold the optics in HALF giving me a 60" rear projection TV that is no more than 2 feet deep.
The rear projection screen I have is 48X36, it is what they call black strip screen, meaning it has black stripes between the vertical lenticular lines(lenses) on the front surface of the screen.
This is to abnsorb the ambient light within the viewing room. It also enhances the dark contrast.
Has anyone been able to use a high gain front projection screen?
IMHO I think that a high gain screen is the key to the whole system. This is apparent in the fact that I am only useing 1 LOA light, 6 inches behind the lcd screen. The screen eliminates all the hot spots. And drastically improves the the dark contrast
thanks
I have found a front surface mirror at a local glass shop. It is 22" X 32" for $35.00 not to bad a price. This should be big enough to fold the optics in HALF giving me a 60" rear projection TV that is no more than 2 feet deep.
The rear projection screen I have is 48X36, it is what they call black strip screen, meaning it has black stripes between the vertical lenticular lines(lenses) on the front surface of the screen.
This is to abnsorb the ambient light within the viewing room. It also enhances the dark contrast.
Has anyone been able to use a high gain front projection screen?
IMHO I think that a high gain screen is the key to the whole system. This is apparent in the fact that I am only useing 1 LOA light, 6 inches behind the lcd screen. The screen eliminates all the hot spots. And drastically improves the the dark contrast
thanks
Tim, I have a screen which shines light back (supposedly 2 times better than normal screen), I don't know what to call it in english. The thing is, the "view angle" isn't as wide with this than normal screen, so it works best when you look it from same direction where your projector is. "Long" time ago when I tried the ohp head with PC-monitor thing I was looking in to high-power screens which do 4x compared to normal screen (exxppensive) and could get small piece of it to test at home. It worked well since with the ohp/monitor thing the image was practicly black and white but with this I could actually see some colors too
Anyway with this you REALLY had to look it from where the projector was it to work properly. And basicly it goes down like this: The better the screen "shines" light back, the smaller viewing angle.
And one more thing:
The screen I have isn't recommended to use with LCD projector cause it shines some extra "lightstuff" (can't find word for this) back which disturbs, although I haven't really noticed this "phenomenom" myself.
Anyway with this you REALLY had to look it from where the projector was it to work properly. And basicly it goes down like this: The better the screen "shines" light back, the smaller viewing angle.
And one more thing:
The screen I have isn't recommended to use with LCD projector cause it shines some extra "lightstuff" (can't find word for this) back which disturbs, although I haven't really noticed this "phenomenom" myself.
The never ending quest to find LOA worklights
Can you say frustrated. I still haven't been able to find a store that sells the light. Arrgh!! The local Home Depot store is trying to locate them, but at the pace that they are moving it will probably be months before I would get it. So... I have a propostion for anybody that has been able to find them. I am willing to pay a reasonable finders fee (in addition to the cost of the light and shipping of course) to anyone who would be willing to purchase the light and send it to me. I have all the other parts I need, but have to have the light before I can start construction. Email me if you are interested. Thanks.
bixs
Can you say frustrated. I still haven't been able to find a store that sells the light. Arrgh!! The local Home Depot store is trying to locate them, but at the pace that they are moving it will probably be months before I would get it. So... I have a propostion for anybody that has been able to find them. I am willing to pay a reasonable finders fee (in addition to the cost of the light and shipping of course) to anyone who would be willing to purchase the light and send it to me. I have all the other parts I need, but have to have the light before I can start construction. Email me if you are interested. Thanks.
bixs
Online source for LOA
Bixs,
Follow the instructions at the following site and you will be on your way to the 65W fluorex. I found this link on one of the reef-aquarium boards.
http://www.energyguide.com/gear/pro...ewElecUtility=101015TX&Update.x=22&Update.y=9
Bixs,
Follow the instructions at the following site and you will be on your way to the 65W fluorex. I found this link on one of the reef-aquarium boards.
http://www.energyguide.com/gear/pro...ewElecUtility=101015TX&Update.x=22&Update.y=9
LOA Light
Lokost,
Thanks for the reply. The light they have on their site is the outdoor flood light not the worklight. It would put out the same amount of light (I think), but it's big. Something like 11" long, 8" wide and 8" deep. To big for what I am looking for. I also called them to see if they carried the worklight even thought it wasn't listed on the web. Unfortunately, they don't.
bixs
Lokost,
Thanks for the reply. The light they have on their site is the outdoor flood light not the worklight. It would put out the same amount of light (I think), but it's big. Something like 11" long, 8" wide and 8" deep. To big for what I am looking for. I also called them to see if they carried the worklight even thought it wasn't listed on the web. Unfortunately, they don't.
bixs
Hey people try to keep it in the projector and in english.
E-mail can be used for personal stuff.
Anyway yesterday watched Pearl Harbor with my thing. It was cool but it just isn't there yet. I want more brightness, and I'm curious about the LOA, how bright is it really? Are the results "acceptable" with lights off or is it like "can't think of anything better even with all the ambient lights?"
My thing is the "acceptable" one and it's just not enough.
I really need it to be almost equal to TV cause with poor brightness it's just not very enjoyable to watch.
Btw. how come desktop stuff and games seems to "outcome" better than movies? I noticed this already early with the monitor/ohphead thing when I could play across with it, but really coudln't see **** from a movie.
Anyway my LCD has a contrast adjusting-thing and I have more brightness adjustments in the display properties of Windows, so I adjusting them I can get bit better results. With the other fresnel I can definetly get better results but it needs the lightsource be next to it which melts it, right now I have the lightsource quite far away from the fresnel and it works fine.
Okay, I read that LCD-projectors don't like cigarette smoke so does anyone know what this is about?
Another thing is that I read that LCDs start to "fade" (not sure about the word) when they get older so how quickly does this happen then?
E-mail can be used for personal stuff.
Anyway yesterday watched Pearl Harbor with my thing. It was cool but it just isn't there yet. I want more brightness, and I'm curious about the LOA, how bright is it really? Are the results "acceptable" with lights off or is it like "can't think of anything better even with all the ambient lights?"
My thing is the "acceptable" one and it's just not enough.
I really need it to be almost equal to TV cause with poor brightness it's just not very enjoyable to watch.
Btw. how come desktop stuff and games seems to "outcome" better than movies? I noticed this already early with the monitor/ohphead thing when I could play across with it, but really coudln't see **** from a movie.
Anyway my LCD has a contrast adjusting-thing and I have more brightness adjustments in the display properties of Windows, so I adjusting them I can get bit better results. With the other fresnel I can definetly get better results but it needs the lightsource be next to it which melts it, right now I have the lightsource quite far away from the fresnel and it works fine.
Okay, I read that LCD-projectors don't like cigarette smoke so does anyone know what this is about?
Another thing is that I read that LCDs start to "fade" (not sure about the word) when they get older so how quickly does this happen then?
One more question:
I'm using software DVD now (poor-quality), if I would buy proper DVD-decoding card, would the results be equal to real DVD-player device (resolution 640x480)?
I have a TV-card too but I just can't get it working for some reason in either win2000 or win95, I have had it working in w98. I would want to try plugging the dvd-player to the tv-card. I suppose now one has experience on results with that.?
I'm really not intrested in the tv-signal(or whatever)->computer signal converter, I would think it doesn't give too good results. Do anyone have experience with that?
and btw. across in my previous post meant that cool Action Supercross game
I'm using software DVD now (poor-quality), if I would buy proper DVD-decoding card, would the results be equal to real DVD-player device (resolution 640x480)?
I have a TV-card too but I just can't get it working for some reason in either win2000 or win95, I have had it working in w98. I would want to try plugging the dvd-player to the tv-card. I suppose now one has experience on results with that.?
I'm really not intrested in the tv-signal(or whatever)->computer signal converter, I would think it doesn't give too good results. Do anyone have experience with that?
and btw. across in my previous post meant that cool Action Supercross game
DVD with a hardware decoder should be just as good if not better than entry level DVD players. If you're using windows for all this, look at Dscaler and Powerstrip (look them up in google) Dscaler will make your DVDs look absolutely gorgeous, and powerstrip will let you alter the colour settings much better than windows.
Graham
Graham
the screen is pretty key in this equation.
I had an old mid-grade silver screen, a ultra high gain movie screen, my original sheet and my painted acrylic sheet all hodge podged together a while back just for comparison, and i have to say, god damn.
the original sheet was pale as can be, pretty much unacceptable in any dark scene. the painted one and the silver screen were pretty much the same, both of adequate quality. the high gain screen was great though, gave new life to the dark scenes.
i would use the high gain screen alone, but its only fifty five inches wide, and that just dont cut it.
i suppose you could grind up some glass and paste the stuff down onto a sheet with some sort of clear adhesive. that'd be pretty close to the high gain screen for the price of a corona or two. not like i'd know, being under 18 and all.
bitch: i had to add more active cooling elements. i dont think theres a way around it. search far and wide for really quiet squirrel cage fans, they put out tons of air and can be virtually silent.
I had an old mid-grade silver screen, a ultra high gain movie screen, my original sheet and my painted acrylic sheet all hodge podged together a while back just for comparison, and i have to say, god damn.
the original sheet was pale as can be, pretty much unacceptable in any dark scene. the painted one and the silver screen were pretty much the same, both of adequate quality. the high gain screen was great though, gave new life to the dark scenes.
i would use the high gain screen alone, but its only fifty five inches wide, and that just dont cut it.
i suppose you could grind up some glass and paste the stuff down onto a sheet with some sort of clear adhesive. that'd be pretty close to the high gain screen for the price of a corona or two. not like i'd know, being under 18 and all.
bitch: i had to add more active cooling elements. i dont think theres a way around it. search far and wide for really quiet squirrel cage fans, they put out tons of air and can be virtually silent.
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