| Type-E |
| Then I would rather buy a commercial projector. $6000 worth of LED is like 15 years supply of projector bulbs. |
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| Type-E |
| BTW, where did that 10000 lumens come from? is that what we need? |
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| Tim |
Has anyone checked into the SoLux Lamps? They can be found here
www.usalight.COM
It looks to me as though it might be a workable solution.For under $10.00 each.
MR16 (12 Volt) (tungsten-halogen based) Voltage... 12 volts Wattage ... 50 watts Lifetime ... 3000 hours IR Reduction ... 58% UVB ... 2.36 microwatts/lumen
UVA ... 39.63 microwatts/lumen Correlated Color Temperature (CCT) ... 4700K Color Rendering Index (CRI) ... 99.35 Beamspreads ...10°, 17°, 24°, & 36°
degrees
Candle Power (CP) Chart per/sport angle
...10°...17°...24°...36°
8,081 3,998 2,306 1,390
Thanks |
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| Scot_lad |
Yeah, I've just bought an MR16 75W, 12V Dichroic lamp, which apparently removes most of the IR but reflects most of the visible light. All I need now is a 75W 12V power supply - will the one inside my PC work? I guess if you don't hear from me from a while you'll know it doesn't, and I've blown up my PC! :rolleyes:
Does anybody know if dichroic bulbs (which you would presumably cool using a fan as well) transmit a low enough amount of heat to be useful with LCD? I'll try it on my cheap 2" Casio which is all I've got right now :( |
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| Tim |
Hey Scot_Lad
Caution on the computer power supply
Not real sure it will handel that load.
But let me know about the SoLux Bulb.
Am wondering now if I should order one or wait till you post your results.
Good luck with the power.
Tim |
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| Schaef |
| In response to Tim's suggestion to look at the MR16 lamps. You don't want to just look at the CandlePower chart. While that may look impressive, you need to counter that with the beam spread and the throw distance. While the 10Degree lamp looks fantastic light output wise, if you look at its foot-candle versus beam spread chart, you'll see it doesn't produce a very large and bright image, and it just gets dimmer as you go with the wider lamps. You'll get an image, it'll just be dim and probably small. Sorry to be such a spoil-sport, but that's the way it is. (Trust me on this, I'm learning this stuff in theatrical applications) |
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| vdi_nenna |
Hi guys, the color temp looks low on the SoLux, but it's worth a try. Any heat that can be removed is a good thing!
Do you know the life span? |
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| Type-E |
| vdi_nenna: go to www.slickdeals.net they said circuitcity has 1.3mp digital camera for $60 after rebate, get one and show us the result from your experiments |
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| Myren |
LCD is waiting for me when I get back from college (wednesday). 8000 lumen projector sitting beside me. I really need you guy's (and gal's?) help though in searching for some kinda filter to reduce the IR emissions from my projector though, unless my LCD happens to be NASA or Military grade build. I could freaking cook a hotdog in my projector.
Myren |
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| Myren |
oh yeah, version 2.0 is already on the drawing board. Should be interseting. Looking at using a 20 inch fresnel, if I can find one. Should have stepper motors on rails controlling how far apart all the lenses are. I've got designs on a makeshift triangulater based off of pretty much a laser pointer.
All in all, I'm hoping to hook it up to my home automation network so I can just say how big I want the image, and have it adjust the lenses as appropriate to produce the desired effects.
I'm having a bit of trouble with the optics though, namely in choosing appropriate focal lengths for everything. I'm a decent ray tracer, and I can set up a non zoom setup, but making a zoom setup is hard as freaking hell. I'm not even sure if I need this third element at all.
The other problem is the light source. my 8000 lumen projector, just by itself, is bright, but I can already see myself having difficulties with light power, even though I'm not even running anything. I was thinking of possibly (please dont hurt me, and keep reading) going with a quad 500 watt metal halide setup. But I realized I dont have the power on tap, and I'm going the wrong way about solving a problem.
Currently, only about 1/10 the light being generated from the light bulb is going through the fresnel at all. Now, lining the case with mirrors wouldnt help, because the light would just bounce around randomly, pass through the fresnel and go all sorts of random directions. For those that remember physics, what I really need to find a parabolic mirror or something vaguely close to. I should be able to eliminate the fresnel if I set it right, since a parabollic mirror should produce paralle rays when a light is placed at the focal point. I was actually thinking perhaps a large spotlight shell might work well. Problem is, very few spotlights will gimme a beam with 8 inch radius right at the appature, which is what I need.
Anyone know a good source for optic needs? I havent even started looking at costs yet, and that should ultimately be the best determinance of the path I take. |
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| Gunawan W |
10.000 lumens, it's come from my humble experiment and
from reading product data, like this:
http://www.peclamp.com/pecmh2.htm
I used halogen type lamp (floodlight, 300W/220V, 5000 lumens,color temperature 3000degrees Kelvin, 2000 hrs life), output is very dim and some kind of yellowish color. (The screen is 15 feet from the projector).
I think the lamp-lumens was eated up by not so good lamp reflector (schaef explain it clearly, thank's), LCD itself, the lens and the box, due to the nature of basic experiment like this.
So I think the true projector light output was around 200-300 lumens.
Myren proofed that too, if I'm right.
IMHO, don't waste our money and time to find and use lamp with spec: below 10.000 lumens and below 5000 degrees Kelvin light temperature (daylight temperature is 5600 d.K).
The problem with that lamp-spec is, it'll generated so much heat!
Myren,
use this formula to find correct lens:
I used it with Microsoft Excel, so I can play with input number, to get different f lens, or vice versa.
input (in inch):
lcd= LCD diagonal width
sdist= image or screen distance from the lens
img=image diagonal width you want
formula (in inch):
find (ldist)=LCD to lens distance =(lcd*sdist)/img
find f lens= (sdist*ldist)/(sdist+ldist)
if you want to play with zoom lens at least you need 3 convex lens, with the same formula: img lens#1 become lcd lens#2 and img lens#2 become lcd lens#3.
BTW, what type of lamp do you use? 8000 lumens you mentioned, is that lamp-lumens or projector lumens?
Metal-halide lamp you're going to use is better, because
the color temp. will reach around 5000 d.K, but again it'll depend from the lamp-lumens, to get bright enough image on the screen.
Someone, somewhere I forgot, wrote that using 2 layer of glass in front of the lamp with 1 inch spacing between glasses and blow the gap with powerfull fan might help to reduce heat, worth to try.
goodluck. |
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| Myren |
raw heat is only part of the problem i think. i'm thinking the energy of the light itself, particularly in the near red infrared, is going to be dangerous, even though its technically lower energy than UV style light. I think conventional cooling alone is of questionable merit. More drastic measures are needed, perhaps.
The bulb is rated for 18000 lumens, and the projector hypothetically for 8000. Skeptical about the second. I'm thinking repolishing the mirror might help a little, but I'm still disappointed. I was hoping 8000 would be "blindingly bright" range, even when reflected closely off a nice white wall. Not so much.
The bulbs got a pretty good color temp. Still too warm to be perfect, but I was actually pleasantly suprised, having expected far worse.
I'm thinking makeshift screen will help things out infinitely. A real one would kick ***, but i doubt even the miracles of ebay can help me procure this. Anyone know a CHEAP way to turn a 12 foot by 8 foot area into something resembling a screen? Special paint? Special sheets?
Out of curiosity, WTF is with projectors? How can a little thing like that crank out 1000 lumens with a 250 watt bulb? theres simply not enough light.
elaborate on zoom lense setup? I think
Myren |
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| Scot_lad |
Well, I'm getting more and more confused with lenses and bulbs and the like, reckon I'm gonna try something drastic...
I got interested in this projector stuff when I got a three-tube CRT projector, which doesn't work. But it's not too far off being fixable, even though it's the size of a small car. :rolleyes:
Don't know how good this would be, but if I got it working it would happily hang from the roof in dad's garage, which can apparently hold a car engine, although if you saw the size of this thing you'd think it was heavier than a car engine. I'm trying to convince him to convert the garage into a cinema!! It's perfect for it, and the car can live on the drive. Anyway I digress, the point is, I have the lenses from the projector, which could be used with other CRTs if this isn't fixable.
Out of curiosity, the projector is a BEA Lumocolor 4000, has anyone heard of it or know anything about it? The entire internet is devoid of information on it.
The good thing with a 3-tube system is, you get three times the brightness of one screen, without complex mirrors and stuff. I know real projectors have special high-brightness CRTs but this isn't plausible. And anyway, I'm planning on using my projector, of whatever origin, in a pitch black room with the shutters closed.
Any opinions on this?
Cheers,
Chris. |
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| vdi_nenna |
Hey Chris,
I thought about picking up 3 black and white 4-5" tvs and using red, green, blue jels and trying to murge the image, like a CRT projector, but I have no idea how that would look like.
Also, the image would be reversed, unless there is a way to flip the image...:confused: . That might work with rear projection, because they require a mirror to bounce the image.
Just a thought.
BTW-
I did some more work last night on my projector. I got a better image this time around. At close range to the screen, the LED light source isn't too bad, but not great. More would be better, or doubling them. That would be 100 for me. Still cheaper then a replacement bulb for a commercial projector.
Also, I learned that there is much light loss to the rear of the light cluster. I placed a reflective surface to the back of the cluster and it brightened up the image somewhat.
Still, my biggest problem is getting the 8.4" image of the LCD through the lense.
What I'm going to do is find a light tracer and find out what kind of lenses they use.
Also, have you guys seen those projected christmas lights that project Santa and snow men? If those things can project an image...why the hell can't I!!! ;)
The lense I'm using was created for CRTs, one CRT that would be close to the lense.
In other words, if the LCD was 4" across or less, this would work.
Don't give up!
Vince |
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| Type-E |
| vdi_nenna, what kind of LCD are you using? are you using one of those LCD projector panel? How far away are you putting your projector away from your image and how big is your projected image right now? I think your route is fine, all you need is a lot of LEDs. Also, is light's intensity inverse proportional to the distance's squure? So if you pull your projected 2x the distance, you need 4x amount of LEDs. |
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| Gunawan W |
Vince,
maybe I can help you, but I need to know what is focal length (f) of your lens?
What is the distance between the lens and your screen?
You need at least 2 lenses to see the whole image from 8,4" LCD display.
What is focal length (f) of your second lens?
It'll work like this:
The first lens will produce reduced image from the LCD to at least same as diagonal size of your second lens diameter.
The second lens will projected reduced image to the screen.
I am going to use with the same setup:
LCD display 14" diagonal size.
First lens is : DIA= 7,25 cm f=4,446 cm.
Second lens is: DIA=7,5 cm f=9cm
Did you use lenses from Surplusshed (# L1314 GLASS ASPHERIC CONDENSER LENS and TV PROJ. LENS (is it # L1813 ?)).
If yes, please take a look at my earlier post:
http://www.diyaudio.com/forums/show...5&pagenumber=16 |
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| vdi_nenna |
Ok! Now we're getting somewhere!
Gunawan W,
To answer your first question- I don't know the focal length of the projector lense I have now. But, I'm sure it is very short, because the LCD screen (8.4") must be placed almost in contact with the rear of the projection lense.
Somehow, I missed your original post. Rereading it, it answers all my questions
-------------------------------------------------------
;)
Type-E, it's a Sharp 8.4" LCD with s-video, composite and a computer video type input.
The distances were 3 feet and then 7 feet. The image size is difficult to determine, because the whole image is not showing.
It's a circle image. At 7 feet, i estimate the image being 5 feet across.
I have 2 cheap sources for lenses here in the US.
www.surplusshed.com www.allelectronics.com For all electronics, look for the on-line store yellow icon
In the frame of the web page, you'll find a list of products for sale.
Thanks!
Vince |
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| Scot_lad |
I would be careful of any quick fixes. You can find lots of places on the internet which will sell you a "100 inch TV" for around $10. As far as I can see, it's just a fresnel lens which is placed in front of your computer monitor, and I can't seen how the picture from that is any good on your wall. In any case, it would surely have to involve a huge bulky setup or your monitor being close to the wall.
Mind you, it is only £7, so I suppose it wouldn't hurt to try it out. Not me though! |
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| wnichol |
Hello,
I have been following this thread since the beginning. Kinda pigybacking off everyone's ideas. I saw the thread about the 100" television and I had to reply. I am one of the unfortunate people that have purchased one of these. all it is is a fresnel lense and plans to build a projection box(i could come up with better plans myself). The picture quality is not very good. It is very dark. You must have a pitch black room. It projects the image from your tv through the lense so you can tell right there that you will have a dark image. The box itself is very bulky. The people that sell these recomend using between a thirteen and a nineteen inch tv. To get an estimate of how big it will be take your tv and add a foot and a half to two feet to the front. if your using a 19" this could get pretty large. I would not recomend this. but if you want to just mess around with it, it will project a 100" image as promised. The only good thing that came from this project is that it is what led me to finding this thread. Keep up the good work.
Chris |
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| Type-E |
| oh really? I didn't know the tv can be strong enough to project an image. If I have a 27" TV and project it to 100", I wonder if it would be acceptable. Also, doesn't it make the projected image inverted? |
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| Gunawan W |
Some thinking,
Why commercial lcd projector can use small lamp with
not so high lumen and produce bright image?
Because they use very small LCD panel (1") and the lamp
highly focused on LCD, no light spread / bounce around.
They need only XX lumens/inch.
If we use larger LCD panel (let say 14"), we should light it up with 14x14=196 times XX lumens to get the same output!
Am I right?????? |
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| Type-E |
| If the final projected images are the same, and if light is used efficiently, then going through a 1" LCD and a 14"LCD should be the same. We are just not using the light efficiently. |
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| vdi_nenna |
Be careful when trying to calculate lumens. Much of it involves human perception of light intensity.
I agree that the small sized screen, if condensed, will be brighter, because of the sweetspot in the dispersed light.
When using large LCDs, I think it would help if the light is guided to the LCD.
On another topic...
I haven't talked about this before, but the screen type is very important too.
For example, let's use the screen rating of 1 to 3, in .5 increments.
A .5 grain screen is not as reflective as a 2.5 grain screen. However, as the figure rises, the angle of reflection lowers. That means that off axis viewing suffers. If you are using a white wall as the screen, it might not be as reflective. And who's to say the white wall is the correct white color, or colour? ;)
Has anyone used a projection screen for testing?
Vince |
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| Type-E |
| vdi_nenna, a real projection screen will definitely improve the projected image, but I think we shouldn't worry about that until we get an OK picture on the wall. |
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| vdi_nenna |
Please, call me Vince.
Good point. But I still want to see the difference.
Vince |
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| Gunawan W |
With reflector, light can beamed with degrees of beam- spread we want. Ajust lamp distance to LCD panel until lCD panel will fit inside the light beam.
Now, the problem is (see drawing below):
lamp with reflector
. . |
. . v -------H----------->
. ./ . . . . . H .\ . lost of light
./ . . . . . . H . .\
(O . . . . . .H x . () <-- lens
.\ . . . . . . H . . /
. .\ . . . . . H . / . lost of light
. . . -------H----------->
. . . . . . . H=LCD panel
x= useful light beam
ignore the dotted!
If we use LCD panel bigger than the lens, you see, we lost lots of light, only small light beam goes directly to the lens (x area).
Using condenser lens before LCD panel to concentrate light might help, but the lens size must be bigger than LCD. Fresnel sheet, it's easy to find and quite big size, but the focal length (f) is too long. Why?
Because the lamp must put at more than 2f distance from fresnel sheet, to produce concentrate light.
That's why we need more powerful light source to compensate lost of light beam.
My thinking is, using more than one lamp and condenser lens so each lamp can cover partial area of LCD panel and all together beamed to the projector lens.
Any better idea?
If we can find cheap 3" LCD panel with SVGA resolution, it'll solve our problem, anyway, anybody knows, where to find 10" or smaller LCD panel, TFT, SVGA resolution, VGA or component input?
Merry X'mas and Happy New Year to you all.
See you next year! |
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| xblocker |
Hello gunawan,
the light beam of the light source must be imaged into the projection lens. That means, the condensor lens is an optical subsystem, which is a projection itself. The distance between lightsource and condensor should be >f and <2xf. Condensor must be > LCD.
The focuslenght of projectionlens depends of the size of lcd-panel. If focuslenght is smaller than diagonal of lcd-panel there will be optical distortion because of the physics of optical lenses.
xblocker |
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| zark |
| Hey guys, I just found this forum the other day and have read from begining to end. I've been working on a projectior for some time now with recent success. Here is what I have so far. For the ouput lens I have a Delta IV lens from a rear projection tv I stripped for parts, still have the 40" screen for another project. The LCD is a 5" model from Parts-Express which cost around $120. The hardest part of the project was creating a lightsource that would work without a hotspot. The first test was a 50w hologen. It didn't work that great, was like watching through a peephole with the hotspot. I tried several methods of correcting this, but nothing that was acceptable. The second light source I tried was a 300w hologen I ripped from a tourch light. It worked ok, but it still wasn't what I expected and there was the heat issue. The third light source I tried was a 65w flurex light from Wal-Mart ($25) that is equiv. to a 500w hologen and is supposed to produce 8,255 lumen. This worked very well, it was pleanty bright and produced very little heat. I have a 6.5 foot screen to test with and the results so far are acceptable. I have had bad luck since. The ribbon cable on the LCD broke from moving it around testing. I'm going to have to purchase another. I would like to see if anyone else has tried a Fluorex light source and if so, results? |
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| Bitch |
Hello.
I found this thread (what ever that is/means) few days ago and read it through. Few months ago I tried to build this "monitor ohp" where I have the OHP lightbox thing replaced with PC-monitor which I thought was my very cool **** thing invention(apparently I'm not the only one who thought that up) but as we no it doesn't quite work. Too dim. Cool otherwise though, I could get quite sharp picture actually (but very dim :mad: ). Somebody asked about testing to a projection.. ****, I forgot the word. Well I tried anyway the "white thing" which is normally used when projecting something (what ever it is in english, from our language to english it's: whitefabric, so eat that;). Anyway the difference was NOT big. Very slight, as well I got and tried an piece of "highpower" fabric I believe it was or something like that anyway, it's expencive, and quite useless, it's brighter (since it's reflection power is better than normal) but you have to look at it from next to your projector it to work properly.
Anyway. I'm not too much intrested to build anything myself, I mainly just want big screen, with low cost. So yesterday I bought an LCD-projection screen to use with OHP. The shopman told me that I need quite powerful OHP. He would sell one with $500. I don't have one right no at all. So now I was thinking if I can build an OHP myself. Just the lightbox thing. I actually still have the OHP mirror/lense thing from my earlier project. But what would be a good light source then, I tried normal 40w 230V "glow lamp" under the LCD and it was totally useless. I could barely see the picture in the LCD-screen itself. The big problem is probably going to be the heat. I thought I would just try like 3 100W 230V lamps or something or some very powerful one lamp (if I figure out where to get one), put it in to a box which has some kind of air conditioning and some kind of glass in top of it (btw what kind of glass or what ever it is in OHP?) but our house is probably going to burn off.
Just before this mail there was someone telling about his project and his good light source but due to my bad english I didn't understand what kind of light he was talking about. Does it release lots of heat? I read halogen lamps generate very much heat. But would this "combining glow lamps(i don't know again what it is in english, but anyway normal lamp in roofs and allkind of home lamps and ****) work? I was today supposed to do some tests if the light power actually increases when I put on another 40w (well actually this one was 60w) lamp next to the one I already have but it burned so there was my test. After christmas I'm going to go to do some lamp shopping, I just don't know if it's better in the end pay the $500 from real OHP than burning our home...
Anyway, I'm just talking **** here, purging my heart.. Thanks for listening. And merry christmas! |
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| zark |
He is a link to the mfg website of the light I was refering to.
http://www.lightsofamerica.com/
Look for "Fluorescent Worklights" in the products section.
It may work for your project using this type of light and a fresnel lens between it and your LCD. < Just a thought > |
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| siymann |
cheers guys, after stumbling on this topic a day or to ago it has been a very interesting read...
anyway i found a taiwanese company who make / sell small TFT LCD screens....
smallest screen they sell is 4" (but u can get a tv tuner for it) and its quite cheap....
FYI: http://www.redant.com.tw/main.htm
i know http://www.lik-sang.com sell their stuff...
maybe this will help on the quest, as far as i can see the smaller the lcd the better ...
siy. |
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| remp |
Greetings
Zark You mentioned a 65 watt flurex light equivalent to a 500 watt Halogen from Wal-Mart for $25 and with not too much heat
Can you just confirm that what the light looks like etc. Sounds like an amazing light source. |
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| remp |
| Sorry Zark, didn't see your website post |
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| Type-E |
| zark: Can you post some pics of your result? Also, how is your LCD hooked up to video source? what interface does it have? |
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| zark |
The light is actually a work light on a small stand. I stripped the stand from the light and used the housing. It has a transparrent cover over the lamp which I am going to attach a fresnel lens to.
The link below is the mfg. Look under products/Fluorescent Worklights
http://www.lightsofamerica.com/
Sorry I didn't take any pics of the results before I wasted the LCD.
The ribbon cable from the LCD to the driver board tore. Not sure if I can fix it, may have to purchase another.
I'll try to post some pics of what I have so far. This may give a better idea of what I'm talking about.
The LCD I'm using is just a standard 5" with NTSC video in. All I need is something to watch movies and such. I don't really need to project PC video as of now.
The last test I completed worked pretty well. The image was viewable with ambient light. In total dark The image was very acceptable and clear. The screen door effect was noticeable up close, but I wasn't able to get far enough away to see if distance would make a difference. There were some minor alignment problems with the original box, so I built another and was moving everyting over when I tore the ribbon cable from too much movement. Next time I will build a permanent mount for the LCD and go from there. |
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| Type-E |
I think I have to start shopping for what you currently have to build the same thing.
1) Fluorescent Worklights
2) Nec LCD
3) Delta IV lens ??? where can I get that if I don't have a projector TV? |
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| zark |
| I've seen the Delta lens on ebay and on some surplus sites for around $10-25 . The thing to look for is a lens that is made for a 5" CRT, just replace the CRT with a LCD and light source. |
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| zark |
Yea, I almost bid on those same lenses. They are a Delta II where mine is a Delta IV. I'm not sure what the optical difference is but they should work since they are made for a 5" CRT projector anyway.
I'm working on a new mount for the LCD assembly. So I don't destroy the next one. I'm using the old one as a template and will be replacing it with the exact same model. The old one should also work to test alignment and light output somewhat. |
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| zephyr.prime |
| In regards to zark's light source, it may be possible to increase the brightness with the use of a large fresnel lense of the type used in overhead projectors. A lense like that would be very good at focusing much of the light from an omnidirectional light like a fluorescent bulb onto the small space of a ~5inch lcd panel. To get really good focusing, a large parabolic mirror would also be needed. |
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| zephyr.prime |
| By the way zark, if the ribbon cable on your lcd is torn, can't you just replace it rather than getting are new lcd panel? |
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| zark |
I have some fresnels to try out. Not sure if I'll need the mirror or not. The mirror may cause a hot spot in the middle of the image, but with just a fresnel it may spread the light more evenly. What do you think?
The ribbon cables are from the panel itself to the board (micro-soldered). No way to fix. |
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| Type-E |
| If I were to use an overhead projector(replace the light inside) and fresnels, I dont' need the CRT lens, right? |
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| zark |
It sounds like it will work. The question I would have is the long focal length using the overhead optics. The extra distance may cause the lights strength to deminish using a fluorex. I don't have an overhead to try, but I'd like to know how well it works.
I had the light test at the office. At around 2ft away the ouput was 2000 lumen. Any closer and the meter freaked out. I'm not sure what the max is on the meter but the light mfg claims 8225 lumen.
The fluorex light or other omni work more like a strong backlight rather than using a directed or spot light that would be passed through. This is where I had problems with hot spots in the image with other lights tested.
I would try to get that lens on ebay for $10 as a backup if nothing else. |
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| Type-E |
so, what is the projected image when you are 2ft away from the screen?
The auction for the delta II are pretty cheap, but there are no more other auction, if it ended, where else can I buy a crt lens?
How much cotrast does your LCD have? I saw one or two 5" LCD that are around $120, they only have 120:1 contrast, it's really not enough. Can you point me to a good LCD? |
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| zark |
I haven't measured the actual image size/distance yet.
I'm not sure what the contrast ratio is on the LCD, it didn't say in the documentation. It seems to be ok. I'm sure there are better ones out there, but for a $120 its not a bad one to start with. There are some contrast adjustments on the board but I didn't make it that far before damaging it.
The lenses on that site should work, but they look a little high. I would keep looking on ebay for a better price. I've seen them on there several times.
I made a new mount using the old LCD as a template. This one should work pretty well. I'll have to post some pics of it. I'm still able to test the light output and screen fill thanks to the screen door effect.
Wish I could read French, looks like that guy has a good bit of optical knowledge and resources. |
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| Tcheko |
| quote: | Originally posted by zark
Wish I could read French, looks like that guy has a good bit of optical knowledge and resources. |
It is not a guy. It is a school class who made this. |
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| Type-E |
Zark: go to http://world.altavista.com/ and use French to English, then put the url in the webpage box.
Tcheko, about the project, there is a black commerical projector, and then he has a home-made one, to me, it seems that he didn't post any result of the home made one. |
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| zark |
| Thanks for the link... That gives me an idea to try out some things with the lightsource. |
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| Bitch |
Okay,
since I have no clue how to buy an fluoroscent worklight in Finland, I bought normal 500W halogen worklight. I don't know how hot it gets, or how long it lasts, but it costed about $20 so... I did some testing but since I have no fresnel lens, it's useless. I quite don't understand the meaning of the fresnel lens but I gather it somehow magnifies or "evens" the light.. Or sometihng.? Obviously it's needed anyway and I have no clue how to buy it either around here. I have spent hours and hours, (several days) browsing the (finnish) web searching for **** but nothing found. Easiest way would probably be to get broken or just generally **** OHP and rip the lens from that, but I'm working on that too. |
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| vdi_nenna |
Hello,
You can get a simply frensel lense from office supply catalog or store. They are called 'page magnifiers'. 8"x11" in size.
www.edmundoptics.com has frensel lenses and an explaination. They are more costly, however. But, the quality of optics rises also.
I have added some initial links from early in this thread to my web site. www.geocities.com/vincetronic
I will add more info as time permits.
Hope everyone had a good holiday. Have a safe New Year!
Vince :D |
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| Bitch |
Hmm.. Does this page magnifier have no difference in to an ohp lense?
Anyway, I managed to buy an used OHP today, $25, 900W bulb!!!
I'm quite thrilled and excited right now, it works with my panel (proxima ovation 810) quite well. The original idea was to get **** ohp and rip the fresnel of but this ohp works straight (has enough power) for the lcd anyway.
But since nothing goes smoothly (in my life) something sticks. Something is not quite right with the OHP, when nothing's on it, the "box"(white image) it puts out to the wall isn't flat white. It has some black **** (circles and stuff, i don't know how to explain it). Anyway the light doesn't spread(!?) as it should. The guy who sold it said that the glass has been changed after it broke, to some "tailored" one or something, I didn't quite listen to him, I thought he was talking about the glass on the fresnel, not the fresnel lens itself but.. I don't know. I'll study the thing tomorrow anyway.
Even while it's not working properly right now I'm quite happy since I wasn't expecting anything from the OHP (I didn't have a clue of the power of it's since I went to get it just for the fresnel).
This is quite far away from DIY right now but cheap and generally cool **** at least! |
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| Type-E |
| *****, I thought zark's setup doesn't require a frensel lense and there is no hot spot on the projected image. |
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| fender4 |
I found this thread two days ago, and I'm really fascinated by this topic and impressed with the ingenuity in these posts. I have a few questions:
Are there ANY links to sites with pics of DIY setups or projected images created by these projectors? It's almost comical that nearly every post I've read here and elsewhere has someone that has completed one or at least attempted it, but something prevents a photo from being taken. Just curious.
Also, I'm sure this has been adequately covered, but I'm new to video (I've only done audio projects in the past)...what can I do with a raw LCD TFT display from a laptop? What connectors and drivers are necessary to show video on these? Is it worth my time?
I found this LCD for sale:
10.4" VGA TFT MATRIX COLOR 700 SER LCD DISPLAY
Can I work with this? The price is right.
Thanks for giving me a new project to think about! Hopefully I can get to work on one of these as soon as I bring myself up to speed on the details.
fender4 |
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| Bitch |
uhh..
The fresnel lens I have is a piece of ****.
Originally it was wrong way around in the OHP so the image was much better after I turned it around but the was still one not-too-big black circle thing in the center of the screen. Okay, now I covered some places around the ohp where there was extra light coming out, trying to leave the air-things free though. After using the thing for like ½ hours the black circle had grown big time. Well actually right now, there is just bright spot in the center and then dim **** elsewhere except the roundings (if that even means anything). The OHP where hot like anything and the air wasn't quite moving so maybe it was bad idea to start covering the thing in anyway. This is why I'm not a diy-guy, all I can do properly is destroy something!! Anyway I don't quite know what this is, could the fresnel lens get destroyed when it gets too hot? It is quite "unformed" when I look at it in my hand. How would I explain it... bend.. turned, twisted and ****, I don't know. (btw. I gather this ohp fresnel is totally something else than a "page magnifier" since you can't see **** through this one.) I've tried it in my DIY OHP-**** thing and it's the same business. same figures, hot spot in the center and dim **** and lighter **** in the sides again. It seems that the 500w worklight is too weak for my panel, but I'm not entirely sure about this since the test was very short and the fresnel isn't obviously working properly. The OHP doesn't turn on when the "hatch" is open so I can't see how bright the 900w bulb is. It would probably kill my eyes so good being so.
Well anyway about the fresnel, it wasn't working properly when I got it in the firstplace so I don't feel so bad after destroying it completely (although I quite don't understand what caused this). But now I would just need a replacement fresnel. I don't know where to get it though. I mailed to few places which repair ohp:s. If it's not too expensive I'll probably try to get this ohp fixed properly since even it's old I think it's not (or haven't been) cheap toy.
Anyway meantime I was thinking about that other OHP-head I have, does the mirror in it cause lots lost of light? If I remove the mirror I should still be able to project with the lens it has, since with my DIY-**** version, it doesn't have to be positioned like OHP is.?
Okay, happy new year anyway! |
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| Anayet |
What is it exactly that the light being brighter do? Does it just give a brighter picture, or would it give a clearer picture?
Has anyone made a working version yet?
This is really interesting i have to say:)
And also, the so called 100 inch TVs (in ebay etc), where you use your TV and a box are not any good. I know, cause i tried them - tried them and tested with different things.
Used different sized freshnel lens (which gave interesting results, if not a bit strange), used different sized boxes, used different ports for the lens etc.
The problem with the Normal TV and a lens+box is that, the picture gets projected, thats true - HOWEVER, the picture is SOOOOO blurry, that you'll think you've gone blind. Its just blurry, so for example if you saw a projected person, you'll just see an outline, no details.
The Hardware Project is more interesting, but i don't know much about these, so have been just reading for a while.
Happy New year!:)
Anayet
ps. whats the biggest sized fresnel Lens that can be brought?
Where can i buy ones that are bigger than just 30cm/12inch ??? |
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| dwalls32 |
I have changed my project and haven't worked on it during the holidays, but pics on my webpage show initial progress.
I am getting ready to retool with a smaller lcd. |
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| Bitch |
I'll have to take back what I said about my 500w worklight not being powerful enough. I did some more testing today (the diy ohp **** box without fresnel) and I could get the center of the image brighlty and clearly when all other lights in the room still on. All I really need now is properly working fresnel.
dwalls, can you give the url for your web page?
Anayet, brighter light makes better brightness, it doesn't affect in the picture clearity. |
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| dwalls32 |
Sure, these are pictures of my first design and first prototype.
http://home.tampabay.rr.com/wwalls/lcd.htm
B**ch, what are you using for your LCD? I was getting the same center light problems as you, even with the brightest light I had with the large lcd I was using. |
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| xblocker |
Hello *****,
there's something you should know about optics. Every light that does'nt reach projection lens is lost light. The same, if light incidence angle is too steep to be refracted into projection screen.
The optimal light dispensation you get is when light source is a point light source, placed in the optical axis and nearest around. If light comes from outer regions the condensor (fresnel)lens will refract this light into other directions beside projection lens. A 500 w working light isn't a point-source light! Therefore a condensor doesn't make much sense. Look at different transmissive projectors, OHPs, slide... they don't have large sized lightbulbs. The size and focal lenght of condencer lens depends of the size of the projected object, in our case a LCD-Panel. What i've already said in another thread: The lighting system is a subsystem of projection. The lightsource is projected itself into the focal plane of projection lens. A working light has huge dimensions compared to lightbulbs. It's working like many small lightsources, but with less light output/area.
Remember, heat is going upwards. With 500 W working light you will have to cool powerfull. Without proper cooling you will cook fresnel lens and LCD. OHPs usually have an addidional IR filter on top of the lighting unit. Why not try with original OHP setup?
Greetings and Happy new Year to all!
xblocker |
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| Bitch |
Okay, first I have to say that I have very hard time reading this stuff due to my not-so-good english skills so sentences like "The optimal light dispensation you get is when light source is a point light source, placed in the optical axis and nearest around." doesn't really say anything to me. So I'm sorry if I misunderstand something.
Anyway what I have right now is working overhead projector with non-properly-working fresnel lens so now I (again) ripped of the fresnel and played around with it in my "DIY projector" which actually is an one meter high plastic clothes(laundry) basket and in the bottom of it is the 500w worklight, and in the top of it lays right now my "non-working fresnel lens" from the ohp and then the LCD itself. And currently it's actually working!
I can get a good picture (light spreads evenly all around the image).
I'm trying to re-read and re-read your post xblocker but I just can't undestand what you are telling to me.
Anyway the thing is, the distance between my worklight and the LCD is one meter (because the manual says to keep the light at least one meter away from the ligting destination).
Without the fresnel, as I told before, I can see just the center part of the image. I could probably see the whole image if I attached the LCD straight next to the worklight but I think the LCD would melt.
But with the fresnel it's working fine now (Which is bit weird but I think the one meter distance from the light does it).
Now I have three problems left:
- Projector head mounting
- Housing
- Heat
Currently I'm keeping the projector head (the thing with the lens/mirror) in my hand while testing!! But I'm going to build some sort of stand for it.
But what would be proper housing?
I was amused by the dwalls projector's housing since I have been playing with cardboxes in here myself and thinking if I am sane at all, but apparently i'm not only one:) And now I have this laundrybox which is actually in a cardbox(!) to prevent the light coming out from the holes in the laundrybox.
But in what are you people planning to house your final product in?
The heat.. My tests now have not been longer than one minute long because I currently don't have cooling at all. The LCD has cooler of it's own but it won't probably take too long before the basket starts to melt and the cardbox sets on fire:) I haven't been thinking about the cooling too much, since I have no clue how I'm going to house the thing anyway. I have somewhere a normal "room cooler", thing which has a flect and then it spins around and blows air to the room, I don't know exact word for it in english but anyway I would just disable the spinning and place it in.. in... hmm. Okay, do I have to place the thing inside the laundrybox blowing through the holes, or can I put the cooler outside the box blowing cool air in to the box from the holes (which though probably isn't the standard protocol) but it would be easier to "mount" this way but does it not then work?
In the opposite side/wall to the "cooling" holes there are no holes in the same level but in the upper part there are few holes so I would think the air could escape from there but I have to say that I really don't know anything about anything so please help me!
Btw. nothing to do with the above stuff, I read that LCD panel (used with OHP) passes through 5% to 10% of the lumens of the OHP so if the OHP is 3000 lumens the output from the LCD is 150-300 lumens. I don't know how this applies to your LCDs/applications though.. |
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| xblocker |
Hi *****,
sorry that you don't understand, my english is also not the best. I tried to use terms of physics, especially optics.
Now i try a little simpler: the optical axis is a line which goes from the center of a light source through the center of of all imaging components, lenses, lcd-panel, screen.
Point-lightsource means the light source is just a small light-emitting point. In reality, there doesn't exist such a perfect light source. Mostly light sources like bulbs lamps and even lasers have a size that isn't a small point.
Now we imagine, we had such a small point. Light is going into all directions, like the sun in cosmos, but as little point. You would agree that only a small part of light is going through LCD. The projection lens is still smaller than your LCD. Only the lightbeams which go through your projection lens will reach the screen. That's when you only see a bright circle and the edges are dark. It's called 'hot spot' effect.
So what's with the rest of the light? It's lost, if we do nothing! But there's a chance to regain some of the lost light. We can use a reflector behind the lamp or a so called condensor lens or both. They do no other job than collecting the lost light. But these light collectors work with optical rules.
case1 Reflector:
the lightpoint will beam as said on the optical axis to the screen. If we bring a mirror behind the lightpoint, we have 2 beams: one direct beam and one reflected beam. That means double brightness in the center of image. The rest of beam is now reflected but still in all directions exept behind the mirror. But what to do with the LCD border areas?
We have to move the mirror this way, that the lightpoint is reflected through the window border of LCD. This reflected beam should not only transmit the LCD but also go to projection lens to obtain a screenimage. You will notice that you must tilt the mirror slightly. If you instead of big mirror would take many little mirrors, then you would get a curved or spheric surface. This is called a spheric mirror.
Of course, not in all mirrorpositions you can reflect light through LCD a n d projectionlens. This light is really lost!
Case 2- Condensor lens:
A lens very simular as spheric mirror, but it's not reflective it's tranmissive. In case of lenses we talk of refraction. In both cases light is deflected from it's beam direction.
A condensor lens should always be between lightsource and object(LCD). It is only necessary for lightbeams which don't go into projection lens.
Each lens has a focus point. That means if parallel lightbeams go through they will be concentrated in this point called f. But we don't have parallel lightbeam here. So the distance between lightsource and lens has to be longer than f so that the beams can be concentrated again. It's easy to unterstand that beams who should go through borders of the LCD first have to go through the condensorlens and therefore the condensor lens must have the minimum the size of visible LCD. The f from condensor is important. It determins the distance from lightsource and the distance from LCD. If the distance between lightsource and condensor is too long, then the light will concentrate before projectionlens and diverge again(lost), if it's too short not all concentrated light will reach projectionlens.
Well, why should the light source be as small as can be? A large sized lightsource can be thought as many small lightpoints with the same specifications as talked about. Radiation in all directions. So if we consider the lightpoints away from optical axis we can say, all lightpoints in off-axis positions will reflected or refracted into areas where's neither LCD nor projection lens. Further, these many lightemitting points of a big lightbulb may have in summary great power but the lightpoints near the optical axis aren't as bright as should be.That's the point why projectionsystems should have small lightsources. If a lightbulb is p.e. 100 mm 500 Watts and another has 1 mm 500 watts then in the first case you have 5 Watt/mm. Isn't so good!
I hope thing are little more clear now. For me it's also hard to explain in foreign language. I think if building a projector there should be little knowledge of optics and projection systems.
Greetings
xblocker |
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| Anayet |
Can someone recommend a LCD.
I've had a look at vdi_nenna site, and it has some top links, ands theres a wide selection to choose from.
Which one would be the best for this project (and also the cheapest:D)
Also, what is the difference between these LCDs being sold, and a ripped out old Laptop LCD?
I know these might be very basic questions to you lot, but i am just very interested in this a lot, and would like to learn:)
Thanks |
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| fender4 |
I am with Anayet. I would also like some suggestions on:
LCD sources
What types to use (mobile video, laptop, game system, etc.)
Pros and Cons of each
Resolutions
I know that most of this has been covered, but this thread is VERY long, some of the info is dated, and the "search" feature isn't very useful because of the thread length.
I've read through everything twice, and I'm hooked! As soon as I get a little more confident with finding the right parts, I'll begin work on this project. I'm short on funds, so I don't want to make any large mistakes early on.
Thanks for everyone's help!
-fender4 |
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| PTremb |
| as like most of you i have been sitting in the background since this subject began, reading and waiting for some results.i wish not to offend anyone and i say this in the most scincere manner,but why not start out more simple.as i am comited to another more difficult project at this time i will be breaf.use a 4" lcd display with a crt projector lens such as a deltaII or deltaIV dirrectly in front of the lcd.as these lenses are made for a 5"crt placed in contact or close to it there is no need for trying to converge a large display such as a projector pannel for ohp.the only obsticle to figure out would be the light source.i understand most dont have large summs of money hanging around to purchase a premade system,if we did we wouldnt be here.granted a 4"lcd dosnt have the resolution of a ohp pannel but the end result will still be better than a 6,000$ unit you dont have now.think of this as a prototype with reusable parts.if you can get this working correctly than the lcd unit can be replaced with larger resolution pannel and a change to the lens assembly in the future as funds increase.again i ment no disrespect to anyone here,this is just my thoughts on the project |
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| PTremb |
| after i wrote my little 2 cents worth i decided to look back at other peoples ideas and found what zark was doing.his ideas are the same as mine and i dont want any misunderstanding that i stole his idea and am trying to pass it off as my own.i have entertained this project in my head for some time and decided to forgo this for a dlp project.i have had the main parts for it about a month and will try to get a site and some pix posted as funds allow.again im sorry if i offended anyone |
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| ajira99 |
Here's some interesting news in my email today! Texas Instruments is developing a DMD starter kit w/controller board. You can check out the details at http://www.prodsys.com/dmddiscovery/. As a side note, can anybody recommend a decent LCD panel from a laptop (specific models nos. would be nice) that have successfully been converted to a transmissive panel (similar to a overhead panel)?
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Great!?! And all this wonderfulness is available for the low, low price of $10,000 for the kit or $5000 for just the controller! Doh!! I think I'll stick to bodging mine together from scratch. |
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| Anayet |
Why is two Lens (Fresnel + Projector Lens) required? Why do you need both?
Is the fresnel used to focus the light on the LCD or something?
And again, can a LCD Display from a Laptop be used for this?
Please help me with my questions
Thanks
Anayet |
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| Type-E |
| quote: | Originally posted by PTremb
after i wrote my little 2 cents worth i decided to look back at other peoples ideas and found what zark was doing.his ideas are the same as mine and i dont want any misunderstanding that i stole his idea and am trying to pass it off as my own.i have entertained this project in my head for some time and decided to forgo this for a dlp project.i have had the main parts for it about a month and will try to get a site and some pix posted as funds allow.again im sorry if i offended anyone |
Yes, Zark has figure most stuffs out already. He has also suggested a very affordable light source. I am very afraid to try, because if I build something that suck, the woman will dis me and say annoying things.
Also, I couldn't find crt projector lens on ebay now, nobody is posting them. I will try it out if I can find one cheap..
Also, where did Zark go? he is not w/ this thread anymore? |
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| fender4 |
I also agree with Zark's approach for lighting...although I've never seen one in use, I know that the Lights of America 65w Fluorex light has been used with success in reef aquaria that require high-intensity, "white" light. If the intensity is adequate using these lights, cooling shouldn't present a large problem since these lights are very efficient.
As soon as I find a suitable LCD, I will try a setup with this type of lighting. Home Depot and WalMart sell these lights, I believe. They should be under $35 USD.
Good luck everybody. Let's keep this project alive!
-f4 |
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| PTremb |
| how about using a lamp from a 35mm slide projector,granted they are only good for 70-80 hrs but at 10 bucks its not to hard to swallow,i think the one i had been thinking on using was a ekk model but dont hold me to it.this bulb has the parabolic reflector built into the envelope with the filliment and works on 30 or 40 volts.as far as the lens i think there is a guy thatwas selling 3 deltaII in the home projection section for 30$ if these are gone some of the 100" projector plans things sell the delta with a fresnel.if all gone just wait a day or two and they will be back, plus surplus shed sels them for 10$ http://www.surplusshed.com/list.cfm?Category=Lenses about half way down these are the 77 which are a slight bit smaller.as far as using a panel from a laptop this can be done,but with great expense because it dosnt have the driver seperate from the video card to drive the lcd pixels so this means having to try and puschase one or make one from scratch, personaly i would go with a premade unit with the drive unit built in and figure out how to seperate the board from the lcd as zark has done.anayet the reason for both the fresnel and the projector lens is the fresnel helps to distribute the light evenly to the entire surface of the lcd if the unit your using is larger than 4",and the projection lens makes the lcd image large on the wall. type-e dont let your lady dis you,get her involved for ideas or,just use reason and explain as things go that progress is happening,even if slow any improvement however small is in the greater good to knowlege ,if things dont go good dont get discouraged look at what happened and use it as an advantage to figure out why it happened that way.so when the project is finished however long it takes you can say "i did this" and be proud of your accomplishment.plus if it should break since you made it you can fix it, no going to high dollar shops |
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| Type-E |
| PTremb, can you point me to the 100" projector plan sites that sell CRT lens? |
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| Scot_lad |
Right lads, I'm back again - been reading all the comments but not submitted any for a while, since I've been all over the country during the christmas/new year period. Hope you all had a good one.
I'm still considering testing a 3-CRT method, namely because there is no problem with accurate colour reproduction, no need for any cooling systems, and most importantly, I have three sets of US Precision lenses in my posession, although I'm unsure what code they are - watch this space - all I know is they fit a 5" crt face onto the lens.
As for this fantastic Fluerex (?) light, that sounds perfect for an LCD solution. I'm going to work on that too when I can find a supplier for this light in the UK. (Admittedly, I have not looked yet).
Does anyone know where I can get a 5" CRT in the UK? Black and white would be good. Any info on the fluerex light would be good too!
I'm going to build a mock system with my small pathetic 2" LCD screen in a couple of weeks, when I should also be in posession of a decent digital camera - watch this space for pics in the near future.
Cheers boys,
Chris. |
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| Anayet |
Does anyone know when http://www.whitelightled.com will reopen there site?
I have been trying to buy some things off there site a little after it was posted, and have been shown the same message about "reorganisation".
Does any one know when it will be open again, or somewhere else where i can get White LEDs at a low price like they sell - $1.50 each for 50+ ????
Thanks |
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| fender4 |
Anayet,
All Electronics might carry them, and the prices seem reasonable. Good luck.
-f4 |
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| vdi_nenna |
Make sure they are Nichia LEDs, or something that puts out white light and at least 5.6mdc or better. Some LEDs are blue-ish. Nichia's are the best.
I didn't know the site was down. Hope it comes back up. |
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| Type-E |
| so, does anyone know where I can find 5" CRT projector lens cheap? |
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| Bitch |
Okay, I could get some sort of 70w (osram) fluorescent light from
www.farnell.com but it's lacking some additional information so I really quite don't know too much about it. Doesn't cost anything though. They "support" several countries so can anyone take a look at there and tell if you get anything more of it.?
And now again some not-too-diy stuff:
Yesterday I bought again another ohp so I have now three different ohp:s, one is the first one where the fresnel is ****. Second one is old and ugly as hell but it's working better but it's not quite as powerful. I have been playing around with it now, it's quite cool though. Although I have learned now that not-too-high-quality (software low quality dvd w/640x480 panel) and not-too-bright but big screen is not very good after all when comparing to normal TV. TV is much more comfortable to watch really (not to mention the noise of the ohp and the lcd).
I have now a projection screen as well (one that reflects some light back to you, although not recommended to be used with lcd-projectors) and can get like 60" screen with it. To my wall I can get over 100" screen but it's not too bright with this ohp. With the first ohp it was better and I was supposed to watch a movie with it but then the fresnel got *****ed..
Anyway, this newest OHP is Medium 10Ke, should be _very_ powerful, I got it cheap since it's light has gone and new one costs nearly $200. So no use for me right now, but I am thinking of buying the bulb.
Does anyone know how long an monitor cable can be (in meters please or tell me how to convert feets to meters)? I was thinking buying 2 x 5 meter extension cables but will it work? My computer is next to the wall to where I want to project the screen so the LCD and the ohp needs to be in another end of the room but I don't want to move the computer there.
And btw., I have had to ask this for sometime now but always forgot: what does screendoor effect mean?
Anyway my diy-thing is not moving anywhere since I don't know how to house and cool it properly (being probably the only problem right now). |
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| vdi_nenna |
Screen door effect is when you differentiate between pixels, like when you get too close to your tv and you can see the pixel structure become more clear. Because we are magnifing everything on the LCD we see this to be more prevelent.
This is why it is important to get the smallest LCD sceen with the smallest pixels, or a system where line doubling can be performed.
This is one of the advantages of DMD or DLP projectors, the display element has millions of mirrors instead of pixels, 10 mirrors can fit on a grain of salt. DLPs can give a more film like presentation, but are not as sharp. The also have better contrast, 800:1. |
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| Anayet |
So, how was that LED whitelight light array going?
Does it project a good beam.
I read up on LED lights, and found that, even though they are extremely white, they do not "Project" the light beam like Krypton or Halogen light.
How is your LED light working, does it project a good beam, or is it just white?
Thanks |
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| vdi_nenna |
| It's not bad. Best in no ambient light. Works well with plano-convex lens and fresnel. |
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| Anayet |
Just out of curiosity, regarding the so called "100inch TVs" - the ones where a box with fresnel lens is placed on a TV===
If instead of the fresnel, a projector lens was used, would that give it a clearer picture?
Cause with a good fresnel lens, you can get good pictures, it just a bit blurry - but very cheap.
I know this has nothing to do with this project, but i'm just curious.
Also, has anyone had good results with your diy projector?
What about you vince? Have you had good results with the final projection using the LED lights?
Does anyone know when whitelightled.com will reopen there site? They've been closed for ages - no info on there site at all:( |
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| Type-E |
| I just don't think LED will be a good approach right now, you need $1000 worth of LED to get enough light |
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| Anayet |
WOW - thats far too much, Vince, i thought you said your ones ok:confused:
Anyway, which lighting method would be the best?
Halogen? - How long do they usually last?
Whats the difference with Flourecent lights? is it the same? |
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| Type-E |
| Halogen is too hot for your LCD. |
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| Anayet |
What other choices are there?
Which are both Cheap & Long Lasting?? |
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| fender4 |
OK, this is the way I see it (for what it is worth):
Halogens: Probably too much heat. This comes from the inefficiency of the bulb, the lower K rating (most below 5500K?), and the excess infrared spectrum radiation from the bulb? (also from the low K, or color temperature?)
LED's: Good sources of light in the correct spectrum, that is with white, ultra high output LED's that produce within the spectrum of 5000-6000K. From my understanding, from this forum and my experience with DIY reef aquaria lighting, the light quality is nice, but the quantity (intesity) is not good without large number of these things. But just wait a few years...
Fluorescents: These intrigue me. They really haven't been explored enough (as far as I'm concerned), and they have some potential. Sorry to use this analogy again, but in reef aquaria, high intensity, high quality lighting is needed to maintain health corals, and fluorescent lighting has been used successfully for years. Of course, the issue of point source and linear lighting must be addressed in this case, but lights such as the Lights of America (LOA) 65W Fluorex fixture produces around 6800 lumen (that's just a guess) at over 6000K. It has a fairly small footprint, and it seems that the light could be harnessed by a fresnel. With the high efficency of these lights, heat shouldn't be quite as big of a problem as compared to halogens or metal halides (read on...)
Metal Halides: These are popular (I think) with the commercial LCD projector crowd and also in reef aquaria. High intesity and various color temps (quality, point source light), but they can be pretty inefficient=heat problems. This can be overcome with "cold mirrors", IR filters, and fans, but I would love to beat the heat with just a more efficient light source. However, this might not be practical. I'm not really a practical guy. We'll see how it goes.
This color temp business is related to the predominant spectrum of the light, I think. I have seen 4100K lights that look reddish, and I've seen 6500K that look more white. Above that things start to look blue. This is from my marine aquarium experience, so take with a grain of salt .:rolleyes:
Light technology seems to be making much progress over the last few years, and it's not slowing down. LED's are making big improvements, so they should be considered, especially as the efficiency improves.
I'm just looking for a suitable LCD screen at this point. I'm lost. Any ideas? Sources? Mobile LCDs? Laptop LCDs? I'm clueless. Hopefully somebody will chime in here.
Good luck to everybody with this project. I know I'm late to join the game, but I'm very enthusiastic about it. Please post any progress that you have made.
I'm with Anayet...after all of these post, has anyone had good results? Are there any websites that feature these projects? Vince's and dwalls32's are all I have to go on...thanks guys! Anyone else? Any confirmation of progress will give me motivation, so BRING IT ON!
ANY LCD SOURCES OR IDEAS? POST 'EM!!!
Thanks everybody...have fun with it.,
f4 |
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| Anayet |
RE: Lights - Camera Lights to be precise
You know the type of light that is in a Ordinary Photographic Camera - is it possible to buy one that is just a bit bigger (if required)
How much power do they have?
Cause the flash on a camera is bloody bright (enough to blind you temporarily:D) - i know it takes the power from batteries and in a way charges it self up to give a powerful burst of power, but if one of those types of Lights were to be used (with the same reflector a camera uses) will that not give an extremely powerful light?
And it shouldn't take too much power either.
The lights should not be that expensive (i think) cause they're even on cheap disposable cameras.
Is this feasible?
What are your views on this?
Anayet |
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| Type-E |
| I think those flash won't last. |
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| Anayet |
| quote: | Originally posted by Type-E
I think those flash won't last. |
Can you elaborate on that:)
Is it because those types of light have a short life? |
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| Scot_lad |
The gameboy advance has a 2.3" TFT screen, 240x160 resolution, for what it's worth. Course, I have no idea if you can make it play TV yet.
Sorry if this is useless, every little helps.
As for the camera flash, I'm only guessing here, but I reckon it is only bright because of the very high voltage it charges to, discharging over a very short period of time. If you were to constantly apply a high voltage, I reckon it would burn out very quickly.
I reckon the fluorescent tube is indeed a good idea. And just to try to remove confusion on the point-light source thing.....
The fresnel will only work efficiently with a point light source, I think we have had several diagrams about it. But, say you don't use a fresnel, and you just use a light which gives all it's light out over the 5" (say) of the LCD? Will that not be effectively the same as spreading a point light source out over the same area?
Hope this helps.
Chris. |
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| dwalls32 |
| I was reading a post on dejanews a while back speaking about using camera flashes. Someone there (and I'll have to find the thread) suggested taking several camera flashes and having them strobe in sucession so their light would appear as one continuous beam, and give longer rests for each individual light. |
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| fender4 |
Hey everybody,
I like the flash idea...it's definitely bright enough, but I would be worried about how long those bulbs can last. I know I've had flash bulbs burn out on me just using it once and a while for my camera. I've read a post (maybe in this thread?) about someone cycling a flash at 50 or 60Hz to make "continuous" light. If not this board, maybe here: http://www.greenspun.com/bboard/q-a...l?msg_id=006hui
I found a couple of discussion threads that may be useful for the fluorescent idea. They involve overdriving normal output bulbs to near VHO (very high output) levels. Of course, you can expect more heat and shorter bulb life. These sites are from DIY aquaria pages, so just disregard the fish talk. Also, the PC (power compact) lighting would probably be the most applicable to us. The Fluorex bulb is actually a PC bulb. The links are:
Fluorescent Overdrive from reefcentral.com
From aquariumpros.ca...contains some good pics.
The second link with the pictures uses actinic blue bulbs, but the same process could be applied to a lower color temp bulb like we would need. Also, these are the long fluorescents...PC's seem to be the best bet for this approach.
Here's a pic of a Lights of America Fluorex 65W light. The ones I have seen at Home Depot are made for mounting on a wall, but it has the same basic design.
Light
They claim that it produces 6825 lumens at 6500K. Sounds good to me.
Sorry to focus so much on the fluorescent approach, but it's the only lighting I have much experience with, and it is relatively efficent. And as Scot_lad alluded to, it might allow projection without a fresnel.
Happy hunting. And thanks for the link, dwalls32! Every little bit helps.
-f4 |
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| zark |
I'm using the Fluorex light from "Lights of America" for my light source.
It isin't set as a point light, it's being used a hell-of-a bright backlight for a 5" LCD which is mounted very close to a Delta IV projection lens.
This setup acts works a lot like the original CRT setup. Maybe not as bright as the crt, but not bad.
I dissambled a standard 5" LCD (NTSC) and used adhesive to mount it to a sheet of glass. Then taped off the area of the LCD and painted the rest black to block out any light that wasn't part of the LCD. Once this was done I mounted the glass directly behind the DELTA IV. The tests so far seem to work ok. I need to rebuild the box to get the correct fit for the Fluorex, and also need to purchase another LCD. |
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