I've been lurking here for about six months, tried and failed to make a projector with a 5" car lcd, and now I'm going the stripped monitor/ohp route. I got a converted Wyse Winterm client pc with a 12" SVGA panel, which was actually really easy to strip (took less than three hours, and no little flex cables in the way! I also managed not to break it, which was good) The panel is a toshiba, and I don't know the response time or contrast ratio, but I'm hoping they're good. I got the whole thing for $100, and I don't plan on making it much bigger than 75" diagonal so it doesn't have to be perfect. Anyway, I have two questions for you worthy inventive geniuses of this forum.
1) Is anyone selling an overhead projector in the new york area? Preferably FXL with a triplet lens, but if you have something else that's good I'd definitely be interested.
2) Does anyone have a tried-and-true method of building an enclosure for the stripped lcd out of wood? I only have access to a power drill and a saber saw and I'd like to make as little sawdust as possible. I also have limited wood, and since we just got a foot of snow this weekend I don't think I'll be going out to get some more anytime soon. Also, ideally I'd like to make it portable because I'm going to have to take it home to California and I'd rather not have to ship it.
I would really appreciate any interesting ideas. I also have a 175w magnetic metal halide ballast and a 10000 kelvin bulb with very little use, as well as the remains of my car lcd project (lcd, projection lens, scratched cut-down fresnel lens and a bunch of reflectors) if anyone's interested. Thanks!!
1) Is anyone selling an overhead projector in the new york area? Preferably FXL with a triplet lens, but if you have something else that's good I'd definitely be interested.
2) Does anyone have a tried-and-true method of building an enclosure for the stripped lcd out of wood? I only have access to a power drill and a saber saw and I'd like to make as little sawdust as possible. I also have limited wood, and since we just got a foot of snow this weekend I don't think I'll be going out to get some more anytime soon. Also, ideally I'd like to make it portable because I'm going to have to take it home to California and I'd rather not have to ship it.
I would really appreciate any interesting ideas. I also have a 175w magnetic metal halide ballast and a 10000 kelvin bulb with very little use, as well as the remains of my car lcd project (lcd, projection lens, scratched cut-down fresnel lens and a bunch of reflectors) if anyone's interested. Thanks!!
hey vassarguy , your image is not displaying. You should attach it when posting your message.
btw what happened to your 5" lcd..? How failed ? Could you give some information about your 5" project... thx.
btw what happened to your 5" lcd..? How failed ? Could you give some information about your 5" project... thx.
Sorry about the image. I couldn't figure out quite how to do it.
The 5" lcd turned out to be more trouble and more money than it was worth for the results I was getting. I started out using a 600 watt DYS halogen ohp light, and that worked but was too dark, low contrast, and eventually melted the page magnifier I was using as a fresnel.
I also couldn't manage to get the image evenly lit, so I ended up leaving the white film on the back of the lcd to do that, which still left a hot spot in the middle and cut the light output enormously, hence the dark image. It was fun for a little while, but then the lcd started to heat up despite the 2 100 cfm fans I put in to cool it down. It ended up being an ugly, expensve (around $250), clunky, and difficult design that had too many problems with heat and brightness.
Then I picked up the wrong kind of metal halide setup in an attempt to fix the brightness and heat issues (175 watt metal halide with heavy magnetic ballast and 10000 kelvin color temperature, which I have found is too high for projection). When I made a new design with the new light source and a cut-down ohp fresnel, I was disappointed because I couldn't manage to get the light to focus across the lcd screen.
At the same time I was traveling across the country to go to college in New York, so I had to stop the project. By the time I had all my parts sent over, I had decided to scrap it and try something new.
I'm going to try to attach the picture this time. Let me know if it works.
The 5" lcd turned out to be more trouble and more money than it was worth for the results I was getting. I started out using a 600 watt DYS halogen ohp light, and that worked but was too dark, low contrast, and eventually melted the page magnifier I was using as a fresnel.
I also couldn't manage to get the image evenly lit, so I ended up leaving the white film on the back of the lcd to do that, which still left a hot spot in the middle and cut the light output enormously, hence the dark image. It was fun for a little while, but then the lcd started to heat up despite the 2 100 cfm fans I put in to cool it down. It ended up being an ugly, expensve (around $250), clunky, and difficult design that had too many problems with heat and brightness.
Then I picked up the wrong kind of metal halide setup in an attempt to fix the brightness and heat issues (175 watt metal halide with heavy magnetic ballast and 10000 kelvin color temperature, which I have found is too high for projection). When I made a new design with the new light source and a cut-down ohp fresnel, I was disappointed because I couldn't manage to get the light to focus across the lcd screen.
At the same time I was traveling across the country to go to college in New York, so I had to stop the project. By the time I had all my parts sent over, I had decided to scrap it and try something new.
I'm going to try to attach the picture this time. Let me know if it works.
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ok picture is displaying now.. btw some guy ( vedee ??) in this forum who was getting very good results with 5" lcd panels... He' s even selling these things... ( as diy projector )
Also he was using simple eco bulbs ( I' m not sure..) but he has native VGA 5" lcd panels... So they are " native 640x480 " panels. I' m also looking to ebay for these 640x480 5" panels but I can' t find any...
Also he was using simple eco bulbs ( I' m not sure..) but he has native VGA 5" lcd panels... So they are " native 640x480 " panels. I' m also looking to ebay for these 640x480 5" panels but I can' t find any...
The one I was using was a low-quality sharp 320X234 panel, and the color saturation and contrast with the halogen bulb was pretty bad. I tried getting a 6" vga panel off of ebay, but couldn't find a controller for it, so that was a pointless endeavor. Also, when I got my projector parts shipped over from California the lcd screen didn't work, so I thought it was a lost cause. A few days ago I tried it again and it seems to work again, so I might do something with it as well, I'm not sure.
Also, I've done a little work on putting my pieces together. I took the metal box and screwed the controller board for the lcd onto it with a piece of wood in between. Next I'm going to try to build a box around it, then mount the lcd onto another piece of wood. Should I add a few fans to keep it cool? How high off the stage can the lcd be before you can't focus the image?
Here's a picture of what I did with the metal case and controller board:
Also, I've done a little work on putting my pieces together. I took the metal box and screwed the controller board for the lcd onto it with a piece of wood in between. Next I'm going to try to build a box around it, then mount the lcd onto another piece of wood. Should I add a few fans to keep it cool? How high off the stage can the lcd be before you can't focus the image?
Here's a picture of what I did with the metal case and controller board:
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lower res = more screendoor effect ( pixel magnifizatione )
higher res = less screendoor effect " "
Absolutely yes. Heat causing dead pixels...! My advice is; use two case fans. First for air input , second for exit.
I' m sorry but I don' t know about other question...
higher res = less screendoor effect " "
Absolutely yes. Heat causing dead pixels...! My advice is; use two case fans. First for air input , second for exit.
I' m sorry but I don' t know about other question...
Well, I ended up going to my college's media services office and they let me borrow a crappy Elmo overhead. It's portable and folds into a suitcase, but it uses a 300W bulb and just s singlet lens. Also, since it's portable, the focus options are limited. But I managed to get it to work decently well. Here's a screenshot of my desktop (an escher drawing) with the lights on:
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The image is about 50" high and 65" wide, so that's a diagonal around 80." Not bad for a college dorm room. It's projected onto the stucco walls, which aren't that bright, and I'm hoping to make a diy screen for it in the near future. Here's the desktop with the lights off and almost all ambient light controlled:
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Here's some family guy. Animation seems to work the best. Live action movies seem to get really low-contrast in the darker scenes and get some solarization, especially with skin tones. Is this because of the weak overhead projector, or is it a problem with the panel? Any input would be great. Thanks.
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I tried Top Gun, and was really disappointed because the dark scenes really didn't come out. Everything just seemed to blend into a neutral grayish color and I couldn't see much detail. Here's a scene inside the aircraft carrier near the end of the movie:
While the actual image isn't quite as bad as it looks from the photo, it's still not as good as I would like it to be. Please let me know if any of you have any ideas about how to improve contrast and brightness. (I know a better projector would be nice, but right now I have no way of getting one.) Thanks!!
While the actual image isn't quite as bad as it looks from the photo, it's still not as good as I would like it to be. Please let me know if any of you have any ideas about how to improve contrast and brightness. (I know a better projector would be nice, but right now I have no way of getting one.) Thanks!!
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HMmm
Anybody who knows better feel free to kick me in the man-lumps and correct me. 🙂
I belive the 'dark scenes blurring into a blob' problem has to do with contrast.
Thats the 300:1 or 450:1 type numbers you see on LCD specs, the higher that first number, the better the contrast.
and the better it handles 'near black' sitations/RGB.
the lower that contrast number, the sooner the LCD says 'okay, thats black!' when in fact,there might not really be any 'black' there, but more of a 'near black'
for example, a 500:1 LCD panle does pretty darn good.
whereas a 200:1 LCD is utter crap, and is likly to really choke on any dim scenes whatsoever.
I'm pretty sure thats correct.. There are threads on the forum you can search for to find out. (which is where i got my info, just re-iterating what i remmeber)
also, LCD response time is important too. 30 MS response time (also refferd to as a sum betwene pixle rise and fall response, or rise/fall typical/average) is pretty bad. some people say they can get by with 25 or 20. but i'm currently looking for a low response time LCD with a moderate contrast (450:1 at least)
(mine is going to be for games and movies)
Response time has to do with how fast pixles 'change', IE: going from one color to the next as there is motion on the screen. (remember really old laptops, and the nasty smudge effect when things moved around? thats the response time, it was pretty nasty and high back then)
Thats all I can think of. and FAIK I might be completely wrong.
Anybody who knows better feel free to kick me in the man-lumps and correct me. 🙂
I belive the 'dark scenes blurring into a blob' problem has to do with contrast.
Thats the 300:1 or 450:1 type numbers you see on LCD specs, the higher that first number, the better the contrast.
and the better it handles 'near black' sitations/RGB.
the lower that contrast number, the sooner the LCD says 'okay, thats black!' when in fact,there might not really be any 'black' there, but more of a 'near black'
for example, a 500:1 LCD panle does pretty darn good.
whereas a 200:1 LCD is utter crap, and is likly to really choke on any dim scenes whatsoever.
I'm pretty sure thats correct.. There are threads on the forum you can search for to find out. (which is where i got my info, just re-iterating what i remmeber)
also, LCD response time is important too. 30 MS response time (also refferd to as a sum betwene pixle rise and fall response, or rise/fall typical/average) is pretty bad. some people say they can get by with 25 or 20. but i'm currently looking for a low response time LCD with a moderate contrast (450:1 at least)
(mine is going to be for games and movies)
Response time has to do with how fast pixles 'change', IE: going from one color to the next as there is motion on the screen. (remember really old laptops, and the nasty smudge effect when things moved around? thats the response time, it was pretty nasty and high back then)
Thats all I can think of. and FAIK I might be completely wrong.
Thanks for your response Hudson. I already know that contrast ratio and response time are the most important things to look for in a panel, and I know I picked a panel without being able to find out what those two values were. I'm in the process of trying to figure it out now, but the tech team at Wyse have no clue and the toshiba panel I tore apart doesn't have a model number on it that I can find. However, when I look at the panel when it's sitting on the overhead, I can make out all the dark details and it looks much better than when it's up on the wall, so that leads me to believe the issue is with the overhead and not with the panel itself. Since I'm only borrowing the overhead temporarily until I can get something better, for the moment I would just like some advice on the little things I can do to improve the contrast, (i.e. screen construction, minimizing ambient light, screwing with the controls on my computer, etc.) If anyone has any techniques to improve contrast and brightness with either software or parts other than the projector itself, please respond. Thanks!!
Also, if you look around the forum, you'll find a lot of people of the opinion that a 200:1 contrast ratio is actually pretty good. Some even think 100:1 is enough. Most of the projection panels that everyone seemed to love so much had 100:1 or 200:1 at the most. I'm hoping the panel i'm using has at least 200:1, but I won't know until I can get a good datasheet on it. If anyone knows a good place to get datasheets on Toshiba LCDs, please let me know. Thanks!!
I'm afraid i cant really help there, i'm still in the design and planning stages of my projector. (gathering hardware specs, hardware itself, planning design, etc)
And i'm not going the OHP route, either. :-/
I have seen some really nice images around the forum of people doing the OHP thing, and how they have eliminated light leaks and whatnot. i'd say hammer the search and look for examples. 🙂
And the 'elmo' isnt as POS as you think, from what i'v seen around, some of these guys cant get enough of the elmo model OHP's, and seek them out if i remember correctly.
And if people really are having great results with 200:1 contrast LCD's, maybe you are closer to perfection than you think. 🙂
And i'm not going the OHP route, either. :-/
I have seen some really nice images around the forum of people doing the OHP thing, and how they have eliminated light leaks and whatnot. i'd say hammer the search and look for examples. 🙂
And the 'elmo' isnt as POS as you think, from what i'v seen around, some of these guys cant get enough of the elmo model OHP's, and seek them out if i remember correctly.
And if people really are having great results with 200:1 contrast LCD's, maybe you are closer to perfection than you think. 🙂
The Elmo everyone seems to want is the 575w HMI one, i think its the S305 or something. The one I'm borrowing is a portable with a weak bulb and crappy lens. I just put in a bid on ebay for an elmo FXL projector with a triplet lens and still portable, so I'm really hoping I can get that one. I think the model is HP-4K DX. Does anyone have experience with this overhead? Is it any good?
I'm still looking for a VGA box and help with trying to make the picture look better. Cartoons look great, but movies are still difficult, especially with the dark scenes. The image looks really nice on the lcd screen itself sitting on the projector, but when it gets to the wall the details disappear. Is this because of the panel or the projector, or the fact that I'm not using a screen? The difference is really quite dramatic, and I may even post pics at some point to give you a good idea of how it looks. Thanks for any help you guys can give me!
I'm still looking for a VGA box and help with trying to make the picture look better. Cartoons look great, but movies are still difficult, especially with the dark scenes. The image looks really nice on the lcd screen itself sitting on the projector, but when it gets to the wall the details disappear. Is this because of the panel or the projector, or the fact that I'm not using a screen? The difference is really quite dramatic, and I may even post pics at some point to give you a good idea of how it looks. Thanks for any help you guys can give me!
I finally found the specs on my lcd panel. It's a Toshiba LTM12C275A.
Res: 800X600
CR: 250:1
Response Time: 40 ms (slow, I know)
Color Depth- 6bit (256k)
So the contrast is pretty decent, so I'm really confused as to why the picture on the wall still looks so bad. And even though the response time seems slow on paper, the panel handles full motion video just fine.
So the issue still remains: why the lack of detail in dark scenes?
Res: 800X600
CR: 250:1
Response Time: 40 ms (slow, I know)
Color Depth- 6bit (256k)
So the contrast is pretty decent, so I'm really confused as to why the picture on the wall still looks so bad. And even though the response time seems slow on paper, the panel handles full motion video just fine.
So the issue still remains: why the lack of detail in dark scenes?
I am using a 300:1 svga screen + Dukane 670 (with 575w HMI bulb). at the first the picture was dark and uneven. with I used more fans to give it better cooling. the picture got much brighter. of course I have a much stronger light source.
by the way, I may going to make a enclosure, so the dukane will be up for sale in case you are interested.
by the way, I may going to make a enclosure, so the dukane will be up for sale in case you are interested.
I'd definitely be interested. How much would you be willing to sell it for? Also, how much life is left on the bulb and how much are replacements? I'm still trying to stay on the inexpensive side of things, so just an fxl projector might be my next step. Thanks!!
I've been looking at these VGA boxes on ebay. Has anyone used one of them? Do you think it'd be any good? If anyone has a better idea or one they want to get rid of, please let me know. Thanks!!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3064476370&category=298
Oops, put the wrong url in the first time.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3064476370&category=298
Oops, put the wrong url in the first time.
Ok, well nobody seems to be responding to my questions, but I'll ask one more anyway.
My panel is only displaying 256 colors, but it is capable of displaying 256,000. Is there something about the controller that is preventing this from happening? On the website of the company that made the system I pulled the lcd from it says that it can display 256 color combinations from a palette of 16 million colors. Why wouldn't it be able to display full 24 bit color? I just don't get it. Please, someone explain this to me, I'm really confused and sick of seeing people look like they're made out of variouis shades of clay. Thanks for any help!
My panel is only displaying 256 colors, but it is capable of displaying 256,000. Is there something about the controller that is preventing this from happening? On the website of the company that made the system I pulled the lcd from it says that it can display 256 color combinations from a palette of 16 million colors. Why wouldn't it be able to display full 24 bit color? I just don't get it. Please, someone explain this to me, I'm really confused and sick of seeing people look like they're made out of variouis shades of clay. Thanks for any help!
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