| Billett |
Warning: Since my old projector bulb blew I've spent 3 days trying to get the 65w Florescent LOA lamps to work. I CAN'T!
I have two work lights and have tried them in every configuration. I've added reflective backing and even mounted them in new housings. No luck.
The image I get is almost bright enough but completely unfocusable. Movies might be ok but there is no precision, everything bleeds together. That means there is no real contrast. Black is not black and everything is washed out. I guess I figured out what the founders did a year ago.
In fact I'd probably be pleased with my progress if I hadn't seen the focusable sharp clear image from my old light.
I'm trying to resist the quick fix of Halogen and hold out for a good deal on Metal Halide but I don't want to spend much more money... well I do... but I can't... for now my project has reached it's spending limit. I'll have to try to work some overtime.
Later Dudes
Paul Billett - The Nephilum |
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| DeadEye |
after three weeks of following this forum i've got stage 1 completed. (Panel and OHP) Have to go back through all of this before I start on stage 2. don't want to spend a month reinventing the wheel. Just wanted to say thanks to all who have contributed here, for had i not stumbled on these pages I would have not even known that this was possible. The only thing i didn't like was not seeing many pics of results to decide whether it was worth the effort. yeah, i got burned with the 100" TV plan. As i do have a pretty good camera, I'll post some pics for those others who are still reading and haven't taken the plunge yet.
Thanks again,
B |
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| DeadEye |
Apollo AI-1000 OHP
Uses 600w halogen bulb
N'veiw Veiwframe Spectra C
4x8 Sheet of Plastex screwed to the wall. (Haven't finished the frame and all That yet. Considering an adjustable Black curtain like thingy to surround it.
Cumputer running Dscaler or WinDVD depending on the application. |
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| DeadEye |
After Hours of research and hard work I came up with this.
Actually it's just a fan that i had lying around from somewhere that uses 110 and is very quiet propped in the space in back where you roll the cord up that blows in cool air to the vents in back. Scientifically speaking where before after 15 min the reading on the panel was ouch that's gotta be too hot to after four hours I can put my ahnd on it and say yeah surely that's safe. |
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| DeadEye |
| Here is an enhanced image to sort of simulate what i got with the 100' tv method in case some of you haven't fell for that one yet. it's not a real picture cause my results never were good enough to try and take pics. as it's been a while this might even be better than my results. i don't remember. |
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| DeadEye |
And finally here's what i got with the current setup. I have more pics but i'm probably clogging up the thread so this is it.
All in all not too shabby for about the cost of a new 20 incher iv'e got six or seven feet wide. the screen door effect is noticable but actually easier to get used to than the weird ghostly stuff you get on some satellite channels from overcompressed mpegs. The only thing that bothers me at all is if you look real close there is a small hotspot in the middle of the screen. I don't know if this is normal with all OHPs, if it's because my fresnel isn't perfectly flat, or if something else is out of whack. If anyone has any ideas let me know. i'm in the process of re-reading this beast of a document before i start trying to build a more efficient system so maybe i'll come across something, a search didn't help.
anyways, sorry for the long post if it bored you. hopefully it helped some of you. |
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| remp |
Hi Deadeye
I read somewhere in here a while ago that a small piece of cellotape or scotch tape on your fresnel top side helps get rid of the hot spot. |
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| uvodee |
look at Zark's website !!!!!!!
Please, i have told this here before.
IT IS YOU who has to guide the light to the lcd by blocking all the unwanted light! you can do this by using black paint on a piece of glass leaving a frame open exactly the size of the lcd . You can increase this way of working by using a fresnel. Using the fresnel should automatically bring the light into a rectangular shape!
indeed the loa's are floodlight but it is possible to get a workeable beam. As soon as you get that beam, you can be sure that the lumen are enough to look at the picture.
Maybe, just maybe i think i know what happened. The blocking of the excess light should be done just before the light touches the lcd screen ( less than 1 inch, preferably as close as possible, which is no problem because there is no heat to deal with.
Jean-Pierre
(it's not Jean but Jean-Pierre as e.g. Jean-Claude (Van Damme) |
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| Billett |
I hate to clutter up the forum with my dribble but let me describe what I've tried. It may help anyone else who wonder down this road in the future.
Using your ingenious idea and mounting the two LOAs together with one front panel I've varied their distance from the LCD. The best results I've found are with it right against separated only by the plastic panel and a fresnel or two. I have tried several combinations of fresnels (single sided page magnifiers) and in front of and behind. I've seen best results with one directly behind the LCD and one about 15 inches in front to focus the image.
My LCD is 8.5 inches and has protective glass built into the OHP panel about 1/2 inch away from the LCD. (air is circulated between LCD and glass buy a fan but the cooling would be unneeded with the 65 watters.) The glass is at least 1 inch larger than the LCD. This means that the light is not directly against the panel and the waves have some room to bounce around (technical info here everyone... can you tell i don't know much about light)
What i did not do and will try when i get home is to remove that protective panel and attach a tunnel directly from the light source to the lcd. I was more intent on getting all of the light i could to the LCD but of course it was coming from all different directions. Tonight I'll try to build the tunnel. The more i think about it the more i realize it should make an improvement but I'm still buying the MH and ballast. Heck if it works I'll have a back up light source.
BTW I've memorized Zarks website and the only difference i could see is that his LCD is smaller but then i noticed yours is bigger. So i guess size doesn't matter.
Thanks for the pointers Jean-Pierre (got it right this time... but my name is spelled with two Ts... just to confuse everyone)
I'll let you all know how it turns out.
Paul Billett - The Nephilum |
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| uvodee |
I like the result, and that with a OHP ...... and an lcd
by the way what is the size of your lcd screen on the ohp and your 'widescreen" against the wall |
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| CAD |
@uvodee
Which model is your lamp?
Ist the Lamp hot?
I tried a 1000W/220V Halogen Lamp - the brightness was great - but simply too hot! :( |
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| uvodee |
the concept is completely different, CAD
Instead of using regular bulbs that focus, i stole oops copied the idea of ZARK and used regular floodlights from Lights of America, type FLUOREX !!!!!
Each of them comsumes 65 watts, therefor the extreme low heat.
The problem that some of us have had to deal with was channeling of shoudl i say focussing towards the lcd monitor .
According to the box, the lamp produces 6.825 lumen. However, according to my very humble results i think i loose about 15 pct
cause my output is somewhat around 11.500 lumen. The lamps are new, and according to the fluorex technology they will loose about 10 pct during their lifespan ?????
Beacuse they are originally floodlights and not bulbs like MH, the whole contruction should be in line with this philosophy.
It is to say focus all the available light, if necessary work with some mirror, etc etc
i'm sure you will get result such as mine. However, as some stated here, any succeeded solution is a good solution!
Jean-Pierre |
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| uvodee |
I have to admit that the focussing of the light when working with floodlights is the hardest part. Therefore i worked with a frame in front of the lcd ( i basically have 2 but while testing this, it did not make a lot of diiference. The hole in these frames, made out of black photoalbumpaper, are 1 mm smaller than the lcd overall.
I have pictures of this as well, don't worry i will psot them this week.
one thing that worried me in thebeginning was the funny mark in the middle of the floodlight screen, a small cone bublle right in the center of the cover in the middle of the projection.
well this turned out to be a blessing and nothing more.
I used this bubble to position the floodlights exactly in the middleof the projection hole. After that i used it for the right angle position of the the whole projector box( i bought an angle viewfinder at the dollar store and installed it inside the box with a permanent mark!!!)
Strangely and fortunaetly enough, when i started using the lcd screen, i could not find this bubble shade on the screen anymore, i guess it disappeared maybe because of the lenses .... ????? |
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| uvodee |
Does anyone here, that includes the forumboss, please has any kind of answer on my question concerning the fibonacci theory that relates to the golden cut, it is to say why the makers of tv's and other related products have not used the 16.1/10 screen, and why is it still in a 'R&D' stage with major companies???
To me this is like the oposite of the beta/vhs story.
in our 16.1/10 case it looks like these companies will come and tell us in 2 years from now, that we all got it wrong and 16.1/10 is more superior than 16/9 with all the logical consequences !!!!
Maybe we can be some kind of whistleblower if we can collect some more info on this! |
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| Billett |
CAD Jean-Pierre and all other interested parties...
I spent another 2 hours trying to get the LOA FluoreX Floods to work. The best results looked almost exactly like Deadey's 100 inch TV imitation. Visible, almost watchable but with no definition or focus.
I'm beginning to think that Zark and Uvodee should come over to my house when i get the MH bulb and see what a real projector can do... but that's just the frustration talking.
I'll be giving it some more attention tonight and trying to enclose the final lens in a box as well as routing the light directly to the lcd like i did last night.
My MH is in the mail so i won't be playing this game for long!
Paul |
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| access256 |
| I have also been playing with the 65 watt fluorex bulbs. I recently received my 5 1/2" pcx lens with a 12" focal length and did some playing last night. With the LCD right against the lens of the fluorex I got my brightest picture and was able to focus it pretty clear (I was holding the lens and the light in my hand.) The projector is definitely usefull but you must be in complete darkness. Yesterday was an overcast day and I was able to get an image that was recognizable but it wasn't until it was pitch black that the image was pleasing. Still impressed how much of an image can be created with these little lights! But still not bright enough, I think I will call my father in law and get that 400W MH. It would actually be nice to do some testing during the evening instead of waiting until midnight when everything goes dark. |
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| Billett |
| quote: | Originally posted by access256
It would actually be nice to do some testing during the evening instead of waiting until midnight when everything goes dark. |
I built my own projection screen (you'll never get a clear image without one!) using blackout cloth. Not only does it have a positive gain but is also useful for its original purpose. I didn't have enough left over to make curtains but i was able to stretch it across my windows and tack it up. I now have complete darkness at high noon. I'll start burning red candles and hanging pentagrams soon. DIY Satanic Worship now that's a forum.
(Lest anyone think I'm serious the above statements are JOKES! Neither I nor the diyAudio servers nor my ISP nor the desk chair I'm sitting on endorse, support or in anyway condone The Church of Satan... at least i hope not!)
Back on Topic...
I highly recommend the blackout cloth. I thought that i needed a brighter bulb while i was shining at a sheet or the wall but when i got the cloth and stretched it over a frame not only did i get a professional looking screen but a much clearer and brighter image as well. Stretched across the windows it let's me watch anytime of the day i want.
At less than $15 for 3 yards it made a great 82 inch screen in 4x3 ratio. It would make an even wider screen if you took it up to 16x9. I'm making felt attachments to quickly transform it from NTSC Standard to Anamorphic Windscreen and every size in between. BTW black felt absorbs light and when used to boarder your screen will make nice crisp edges and get rid of that annoying overshoot that is never quite square.
Paul |
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| access256 |
| I am actually using an old glass beaded screen from the old Super-8 projector days. It does a good job brightening up the image but too small (Good for testing though). After I get decent results with the projector I will definitely build a screen. I was hoping to make one I can mount on the ceiling and pull when I am using the projector. As for blocking the windows I have this pet peeve about that I enjoy open windows and my kitchen is completely open to the living room (my projector room) and I'm sure the wife will decide to clean the kitchen as soon as I start the projector! Unfortunately I think I'll have to go with more projector output :( |
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| chukie1 |
| hey all can anyone tell me if you need drivers for the diffrent projector panels like the spectra c etc |
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| Tinker |
| Dirvers? You mean like monitor drivers? No you should already be able to support vga output for these with standard windows monitor drivers....plug N prey (plug-N-play)! If its s-video or rca your video card must have tv out and it will have the drivers needed.:) |
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| chukie1 |
| hmm i see i am working with a sharp qa 1000 640x480 vga but it looks like **** i am using my ati allinwonder tv card but my desktop looks all distorted like it is using the wrong video driver , i wonder why . i am at 640x480 have tried all difrent kings of color settings no luck. |
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| Mario007 |
| Chukie try powerstrip. It's a really cool program for adjusting your monitor and a bunch of different settings. That might help you. Also try changing your sync in the panel menus the sharps have an option for it and it can make a big difference. Try a different video card that can make a difference too. |
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| DeadEye |
| quote: | Originally posted by chukie1
hmm i see i am working with a sharp qa 1000 640x480 vga but it looks like **** i am using my ati allinwonder tv card but my desktop looks all distorted like it is using the wrong video driver , i wonder why . i am at 640x480 have tried all difrent kings of color settings no luck. |
is it the whole display or just the tuner part? i had one of those that the rf tuner looked like that from day one but the video input was fine. when i got this projector thing going both inputs did it so i gave up and got a cheap tv wonder card. sometimes it does it to with dscaler. i found if you switch to pal and back to ntsc it fixes it. if its the whole display i don't have a clue 'cept maybe refresh rate my nview panel says it can only handle 60 hz.
Good luck |
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| DeadEye |
| my LCD is like 6x8 in. at about 11ft away my OHP projects about 6.5 or 7 ft wide. which is about all i want as my couch is presenly only 8ft from the wall. big is cool but you don't want to have to move your head to see from one side of the screen to the other :) |
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| Tinker |
| quote: | Originally posted by access256
I have also been playing with the 65 watt fluorex bulbs. I recently received my 5 1/2" pcx lens with a 12" focal length and did some playing last night. With the LCD right against the lens of the fluorex I got my brightest picture and was able to focus it pretty clear (I was holding the lens and the light in my hand.) The projector is definitely usefull but you must be in complete darkness. Yesterday was an overcast day and I was able to get an image that was recognizable but it wasn't until it was pitch black that the image was pleasing. Still impressed how much of an image can be created with these little lights! But still not bright enough, I think I will call my father in law and get that 400W MH. It would actually be nice to do some testing during the evening instead of waiting until midnight when everything goes dark. |
was the light really that cool! I mean could you keep it that close without it ruining the lcd? Interesting! Have you tried useing a fresnel between the panel and light source to catch the light before it spreads out too much as it is a flood light not a spot light? That should help stop it from continuing its outward pattern and focus it back down into a more concentrated beam. These bulbs (fluorex) are very ify. Some say it works well others say not. Personally I'm having best luck so far with spot lights (halogen:( ) for track lighting. But heat is a issue there. At 90 watts I'm getting a good picture at 150watts it would be great! I measured the image and its 62" diagnal. Big enuff for me, especially compared to my 29" CRT tv.
P.S. Does anyone know if these fluorex lights come in spot light bulbs aswell, that would really be ideal.:D |
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| uvodee |
i put the thermometer inside the box (with only the psu fan on and it is a cozy 90* or so inside
my 2 fluorex lamps are literally inches away from the lcd screen seperated by a plastic hood, a glass hood and a plastic fresnel and let me tell you there is NO heat getting that lcd..
i wish they would make stronger fluorex than the 65 watt, if so, i think my box could me much smaller..... but i sent lights of america a n email asking this and they have not replied so far.
beware that the bulbbase of the fluorex is mogulsize (i think that is what they call this here, and these bulbs need a pretty serious kind of ballast or how do you call that side pcb...
i have noticed that without metal cover these ballasts interfer with the quality of the picture, they distort it somehow... |
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| uvodee |
Maybe this sounds a bit harsh for some of you, but i find it utterly amazing that there is some argument or complaint that it has to be dark before you can see a nice bright picture on a 6ft (or bigger) screen??????
I have never been in a movie theatre where the movie was presented in a) broad dayllight, b) with the full lighting on.
as a matter of fact, in Belgium all the modern theatres have no lighting fixtures, only build in floorleds , including emergency leds.
If you agree with the fact that movie theatres don't play movies when daylight enters or the spots are on, then you should (i think so) accept the fact that your humble project should get the same treatment, it is to say dark, pitch black room , just like the AMC theatres in Federal WAy (oops, AMC closed all 6 down permanently on Labor Day ) or at the 24 Metropolis theatres in Antwerp, Belgium. |
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| access256 |
Yes the LCD is right against the lens of the light and it does stay remarkably cool. I have tried frensels. 1 right behind the LCD and then 2 frensels to condense the light right to the back of the LCD and no luck. My frensels are simply page magnifiers and they appear to loose too much light going through them to be effective. It would probably better to build a condensing system out of glass optics (WAY MORE EFFICIENT) then the frensels. I couldn't believe the difference in the light my glass optic let through compared to the frensel on the projector side. But I have had the best results by simply putting the LCD right against the lens of the fluorex.
As for the darkness of the room. I think it would be nice to have the movie on and still have a little light in the room so that my guest can get the the bathroom without breaking their neck! And my wife says no way to installing floor lights! |
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| Billett |
| quote: | Originally posted by access256
And my wife says no way to installing floor lights! |
FLOOR LIGHTS!
I never thought of that! That's the perfect finishing touch on my theater/entertainment room!
Thanks access256!
Now lets come up with a way to dupe the wife!
I agree with unvodee about the darkness thing. The less light there is in a room the less you are bothered by miscellaneous distractions and the more attention you can focus on the movie. That's why movie theaters don't have to sweep their floors. No one ever sees the mess.
Get this... Remote operated dimming floor lights...
...so when someone complains they have to pee rather than interrupting the show for everyone you just bring them up slowly to show the way to the bathroom. Then shut them off so the person with Tiny Bladder Syndrome can't find their way back in.
To find out more on what is available in the FloureX bulbs go to www.lightsofamerica.com and click on "products."
BTW everyone these lights are going for $45 to $65 plus shipping on eBay. Wal-Mart has them for 25 although I had to go to three stores to find one that had them in stock. (Although Zark and Unvodee disagree, I don't recommend using them in a projector. The best image I got was less than 1/2 the quality I want and about 3/4 of the brightness I need. Still I'm keeping them for a new hobby... hydroponics.)
Paul - The Nephilum |
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| Tinker |
"The best image I got was less than 1/2 the quality I want and about 3/4 of the brightness I need. Still I'm keeping them for a new hobby... hydroponics.)"
1/2 the quality? You mean the temp of the light or was it hard to focus cause the light reays are too scatterd? 3/4 the brightness you need? What size are you projecting too? To give me a ruff idea if it'll be enuff for me. I'm not going as big as some of you on this, dont have the room. So it may be enuff for me. Heck I'm getting a very watchable pic out of a 90watt 1100 lumen halogen Plus 10o beam SPOT light from GE. hydroponics, I'm sure it is good for that as some are using these for reef lights I saw. Suposedly there a huge hit in the aquarium hobby. I'm building my own 500gal. tank soon , salt water, corel reefs etc. Done it before with a 100gal, its easy once you balance it all out like ph and density etc. If it doesnt work for projector I can always put it back for in the future.
Went to lowes today looking for those lights but none found. Have one more local wall-mart to check though. Its bigger so hopfully they will have one. But on a positive note the lowes lighting guy is calling Ge tomorow and phillips for me. Hes giving them the specs to that light and hoping to find somthing similar for me. He was very interested in these projectors. I told him the nec. info. so he knew what was good or not. Like LOW heat, close to a point light source as possible. Not way expensive and lots of bulb life hours. Bright white color temp. like 6000k. And 6-8000 lumens o rhigher if possible with the least amount of watts. He's calling me tomorow, I'll see what he finds out from them and how much!
:) |
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| access256 |
| quote: | Originally posted by Billett
FLOOR LIGHTS!
I never thought of that! That's the perfect finishing touch on my theater/entertainment room!
Thanks access256!
Now lets come up with a way to dupe the wife!
I agree with unvodee about the darkness thing. The less light there is in a room the less you are bothered by miscellaneous distractions and the more attention you can focus on the movie. That's why movie theaters don't have to sweep their floors. No one ever sees the mess.
Get this... Remote operated dimming floor lights...
...so when someone complains they have to pee rather than interrupting the show for everyone you just bring them up slowly to show the way to the bathroom. Then shut them off so the person with Tiny Bladder Syndrome can't find their way back in.
To find out more on what is available in the FloureX bulbs go to www.lightsofamerica.com and click on "products."
BTW everyone these lights are going for $45 to $65 plus shipping on eBay. Wal-Mart has them for 25 although I had to go to three stores to find one that had them in stock. (Although Zark and Unvodee disagree, I don't recommend using them in a projector. The best image I got was less than 1/2 the quality I want and about 3/4 of the brightness I need. Still I'm keeping them for a new hobby... hydroponics.)
Paul - The Nephilum |
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| Tinker |
| Why the qoute and no responce????:bigeyes: |
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| access256 |
| quote: | Originally posted by Billett
FLOOR LIGHTS!
I never thought of that! That's the perfect finishing touch on my theater/entertainment room!
Thanks access256!
Now lets come up with a way to dupe the wife!
I agree with unvodee about the darkness thing. The less light there is in a room the less you are bothered by miscellaneous distractions and the more attention you can focus on the movie. That's why movie theaters don't have to sweep their floors. No one ever sees the mess.
Get this... Remote operated dimming floor lights...
...so when someone complains they have to pee rather than interrupting the show for everyone you just bring them up slowly to show the way to the bathroom. Then shut them off so the person with Tiny Bladder Syndrome can't find their way back in.
To find out more on what is available in the FloureX bulbs go to www.lightsofamerica.com and click on "products."
BTW everyone these lights are going for $45 to $65 plus shipping on eBay. Wal-Mart has them for 25 although I had to go to three stores to find one that had them in stock. (Although Zark and Unvodee disagree, I don't recommend using them in a projector. The best image I got was less than 1/2 the quality I want and about 3/4 of the brightness I need. Still I'm keeping them for a new hobby... hydroponics.)
Paul - The Nephilum |
Are they the correct spectrum for hydroponics? Because I would like to grow a crop of cherry tomatoes at work throughout the winter and have a good source of snack material throughout the winter! But I have to agree on the quality it's not where I had expected. I was all for it when I saw fluorescent and cool temps but when I got the MH available at $0.00 I was instantly hooked. I could possibly have an eight foot screen with excellent brightness with ambient room light! Damn thats like having your cake and eating it too!! But I think a glass optic condensor setup as opposed to the frensel way to go. More efficifent and accurate. I will definitely post my results and pics when they are worth while..... |
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| access256 |
| quote: | Originally posted by Tinker
Why the qoute and no responce????:bigeyes: |
Sorry, I got trigger happy with the mouse..... |
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| JahklaR |
REDEVIL...
Do you have any pictures of your setup that you can post or email? |
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| uvodee |
here you can see how i extended a flex laminated cable that was originally 1" lang into a 10" one.
Thank you Mr Mike Birch of Parlex!!!! |
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| woneill |
Hi Guys,
The fluorex lights are very bright, but suffer from a major problem when being used for projection: They output a pure diffuse light!
This calls for different optics than would be needed for a point source/parallel beam arrangement, and imposes some potentially serious limitations. That said, they SHOULD still be very usable if done properly...
First, the limitations: LCDS are quite directional. They will favour the transmission of light at a fairly narrow angle. The optics in the OHP projectors, and the variants with a parallel beam going through the LCD are inherently more efficient than a fluorex setup because most of the light hitting the back of the LCD is at an angle that the LCD can transmit. (Even then, the maximum efficiency of an RGB panel is about 15%.)
With a diffuse light from a fluorex lamp (or multiple lamps), only a portion of the light hitting the LCD will be within the transmission angle that the LCD supports.
A fresnel will not help unless the lamp assembly is significantly far away from the LCD. Otherwise, it will be simply altering the path of randomly diffuse light - producing more randomly diffuse light...
The best bet would be to encase the fluorescent bulb(s) within a front-surface mirrored box, so that as much light from the bulb(s) hits the LCD as possible. White surfaces (instead of mirrors) will reduce hotspots, but will also reduce intensity.
Ok, if the maximum amount of light is hitting the back of the LCD, then the next step is to make use of it. The light coming from the front of the LCD will be partially directional, and partially diffuse.
The LCD will have filtered out most of the really diffuse components, leaving an output with roughly the same profile as a normal LCD monitor - very bright when viewed head on, but losing much brightness off-axis.
What is needed here is to direct the maximum amount of light from the LCD through the objective lens so that it can be focussed into an image. If done properly, the fact that the light is partially diffuse will not be too much of a problem. It will, however, stress the objective lenses much more than a clean collimated beam would. (In a clean collimated beam, only a small part of a lens surface is used to contribute to each part of the image - the lens is being used more to magnify and direct the beam than to focus it - think in terms of lasers... In a very diffuse beam, every part of the lens surface contributes to every part of the image - any surface irregularities and non-uniformities will degrade the entire image. This is why fresnels are limited in quality as the primary objective, but great at beam shaping for a roughly collimated beam.)
So, with a partially diffuse, but partially directional beam, what is needed is either an objective lens that is as large as the LCD screen, or a fresnel or field lens which can be used to direct the output beam into a cone such that the majority of the light passes through a smaller objective. Otherwise, much light will not go through the objective and will be wasted - reducing the overall brightness and contrast of the final image.
If the LCD is smaller than the main objective, the answer is simple: the beam profile will allow most of the light from the panel to pass through the objective, and the result should be a sharp clean image.
If the lens is achromatic, then the results will be better than if using a singlet, and the larger the lens area with respect to the LCD, the less spherical aberation will be achieved for a given light level: reducing the aperture of the lens will reduce spherical aberation, but will also reduce the amount of light that is used to form the image...
If large enough, Projection TV lenses designed for flat CRTS will work well. Those designed for curved CRTs will not - unless you reduce the aperture - reducing image brightness.
If the objective is not big enough to naturally capture all the light from the LCD, the answer is still fairly simple - put a large (larger than the LCD) PCX lens (or fresnel) as close to the panel as possible and concentrate the output beam into a roughly diffuse cone shape. (Back to the OHP concept...)
If a fresnel is used, it can not be placed flush with the LCD because you will get Moire effects. It must be moved about an inch away. The fresnels are also VERY limited in their viewing angle and directionality. Most (but not all) need their rough sides facing the LCD. They also need the first lens of an objective set to be placed at roughly one focal length's distance from the fresnel.
Thus, if you use a fresnel, you must also match the overall focal length of the objective with the fresnel itself. OHP objectives are already matched to the fresnel lenses they use. A setup using discrete components will need precise calculations to determine a viable combination of the magnification needed and the focal lengths of the fresnel and objectives. If a suitable single objective cannot be matched with the fresnel, a lower power lens could be placed at the sharpest point of the cone, and a secondary lens be used to produce a compound objective with an overall focal length that is based on the focal lengths of the lenses used, and the distance between them - the distance between them could be used as a focussing apparatus that would always ensure that the light is always gathered from the apex of the light cone.
With this combination you should be able to get the best from the diffuse light sources and the LCD. If there is enough light getting through the LCD, there is no reason why a REALLY sharp, crisp image cannot be produced.
Bill.
P.S. Formulae describing the lens combinations can be found scattered through the Part 1 & 2 threads... |
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| uvodee |
i think i understand somewhat the above showed article means.
An i certainly think that results with fluorex are harder than with more 'conventional" lighting methods ... however
one thing i want to make clear: the light output in my case was and still is so strong that i think this compensates a lot of loss due to diffusion .........
for example it was not possible to look through the hole before the lcd was placed. i did indeed sin and have covered a few spots with alu foil, and marked that the output was higher.
I have not yet foudn a way to put a black lite bulb in the box, but i have now noticed after a friend of mine had given me this inof, that colors are even clearer than before, not brighter just more clear.
And today i changed my plas tex waterproof panel into blackout cloth that i bought at Michael's craftstore. The difference ( i am truly sorry to write this here) , is astonishing! i supose the setup with fluorex required something different than plas tex.
I am not aware of the gain win, but this cloth sure does a good job!
the cloth costed me $18.00 and hangs nicely over the frame.
i may end up making a run down screen so that the storage space in the den is easier to reach. |
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| Tinker |
I'm using particle board painted white. Is the black out clothe higher brightness and contrast then that? Let me know, interesting. I've found this stuff called screen goo. Its a paint you use to make your own screen with a gain up to 2.0 or as low as 1.0. Even at gain level 2 it will not cause hot spots suposedly. They have digital grey which is for lcd projectors with lower ANSI lumens and lower contrast and also crt white. Its a blend of primer and paint to get desired gain. Have you guys heard of this stuff? I wrote the co. and the guy was real nice, anyone heard of it? Thinking of trying it myslf.
Check comments here:
http://www.avsforum.com/avs-vb/show...20&pagenumber=3
Product here:
http://www.goosystems.com/
Let me know if you guys think its worht it.:) |
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| Tinker |
Tied it and failed! Got one tonight and spent hours trying to get it to focus the light down, nodda.:( My 1200 lumen spot light is atleast 4x better at 1/6th the power! Well, I'll have to post a pic later today of my results with the spot light halogen bulb I have. I would of the fluorex but couldnt get ANYTHING even worth the while to take pic with it. Well back to square one. I'm just going MH and being done with it! Oh well I got a good work light anyhow.:)
So, after seeing the pics let me know if you all think that a smaller MH will do for me. I'm getting really good results from a small bulb now. 90watt 1200 lumen high presure Halogen 10o spot light. So am I nuts thinking that a 100watt or 150watt would be enuff for my 62" diagnal screen I made. I want twice as bright as I have now in ANSI lumens on the screen. The 100watt is 4000 mean lumens I think and the 150 is 6200 lumens... I dont have ballast or bulb but am ready to get one at this point. Can get setup for about $100 or a little less. Even if I do get a OHP the bulb life is too short so I'm gonna need this ballast and bulb anyhow.
My biggest thing is that it will be a smaller screen 5" diag. It will be a smaller bulb- so closer to a point light source and easier to cool. The reflector will have to be alot smaller aswell due to my 5" screen, in part the reason for my choice in the smaller bulbs. Less heat means closer bulb placement to the lcd resulting in less loss light. BUT you guys are using larger bulbs then me. Like 400 and 600 watters for 6-7' projections and more! The problem, will I have to make a entirly dif. type of reflector than the big ones use? ANy sugestions due to the small scale of my projector relating to my lighting needs/ reflector? Thanks for listening to my "I give up on all other lights" rant and frustration...
Peace.:D |
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| Gunawan W |
| how about the reflector? |
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| Billett |
Well… I’ve been to busy riding motorcycle and WATCHING MY 80” TV to post for a while. That’s right I got my 400w MH bulb and ballast and it’s working very well.
I spent two days trying to come up with some kind of reflector. The bulb is so huge nothing worked so I gave up. I said, “I’m going to watch TV even if it is dim and crappy looking.” I mounted the bulb sideways put a large lens directly in front of it and then the fresnel and LCD. I’m using a fresnel in front to focus the image.
I enclosed it all with a custom built box and WOW it’s great! O sure I’d like a little more light but it is better than usable.
I’ll try to take some pictures but I don’t have a digital camera so development takes money and time.
Of course with no reflector I don’t have a cardboard burning beam but the lens I ripped from a photo enlarger gets a good beam 5 inches wide. Perfect for hitting the 8.5” LCD. Throw in a good reflector and it’ll be more light than I could want.
This 400 watter is big and hot but not to hot. My LCD is enclosed in a box about 12 inches from the light and it remains cool. Before I completely seal the box I will install a fan. Not to keep the LCD cool but to take the heat away from the bulb area where the wood gets very warm.
A 400w MH bulb is a more than adequate light source. 1000s watts guys? Are you in insane? My theater room has a lot of ambient light but the image is clear and bright. I’m in Big Screen Heaven.
Paul |
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| Smoke Eater |
| Hello to all from the middle of Missouri, USA. I'm new to the forum and want to thank all those who make this possible. I'm of limited electrical/video/projector knowledge or experience, but I've been reading all the previous posts and keep running into the problem of the reflectors. From what I understand, Marklar's reflector is something that would work well in most cases? I have two possible suggestions that I'd like to submit for consideration: 1) Lamps made for keeping chicks warm have strong, heat resistant reflectors (and they also have heavy ceramic bulb sockets, however they are for "standard" base heatlamp bulbs and not "mogul"). I can pick these up here for less than $10. They are more "half-spherical (spelling?)" than what I think of as parabolic, and are approximately 10-12 inches wide and 6 inches deep. 2) There is a process called "metal spinning" which is how all these parabolic shapes used to be made in metal (vs. the stamping process used now). There are some shops out there that will still do this for limited numbers. But what I would suggest is if the members of the forum could come up with an "ideal" shape and size of reflector that would work best, I believe a metal hobbyist could be found to turn a few reflectors at a reasonable cost. (I'm looking into a lathe myself and if I can find one to buy or borrow, I'm going to try this technique myself). Again, thanks to all those who are sharing their ideas on this forum. :) |
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| Billett |
| quote: | Originally posted by Smoke Eater
Lamps made for keeping chicks warm have strong, heat resistant reflectors (and they also have heavy ceramic bulb sockets, however they are for "standard" base heatlamp bulbs and not "mogul"). I can pick these up here for less than $10. They are more "half-spherical (spelling?)" than what I think of as parabolic, and are approximately 10-12 inches wide and 6 inches deep. |
I tried one of the chick warmers. Purchased it at the local hardware store and took my dremel rotary tool to it. It work well as a heat shield but did not reflect the light into any sort of recognizable beam. That's why we need parabolic.
I believe that if you were using a small bulb it may work but i had problems getting the light source deep enough into the reflector. I'm using one of the gigantic 400w MH's and would have had to cut away half of the reflector to place the bulbs light source in its center.
So if you've got a small bulb go for it... if not wait for the real thing...
Paul - The Nephilum |
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| Tinker |
Yes, this is what we need as many have said here. You know everyone keeps saying that the lcd panel needs parallel rays and that makes sense as when using a really diverged light source with light going eveywhere you can see light actually refecting off the panel. So its lost-too harsh of a angle to go through and what does pass through causes blur when focusing the final image. Now I've been researching this too, I found similar to this is a aquarium tank. The light will also be reflected due to similar reasons if it hits the surface on too harsh of a angle. So it also needs parallel light. They use parabolic reflectors for this. So its a similar need and solution.
Now light loss over distance is also a prob. Well not really from what I have found. Least not in our short distances. Its more loss due to other factors. The only reason I see why it gets brighter closer to the screen is cause it also shrinks the image down as its a projector. Closer='s smaller-so therefore BRIGHTER. Now the reflector makes or breaks this theory. Several sites I have read from claim that with a parabolic reflector that the light loss after 1' in a shorter distance like this is all the same. So at 10' 12' or 8' you should still be having the same lumens output BUT the ansi lumens will drop due to the enlarged image making the light spread over a larger area. Thus less lumens per foot efecting ansi lumens -blah blah. But the point is with parabolic type reflector you can maintain the nearly same lumens output over any of our needed distances. So lcd at 1' or 2' will be hardly dif. other than lower temp. Thats part of the battle there, getting the most to the lcd....
"Myth: The inverse square law applies to aquarium lights.
Fact: Only the light from a compact bulb with no reflector drops off as per the inverse square law. The illuminance of a single (or dual) fluorescent fixture drops of approximately linearly with distance. And the illuminance of a multi-tube fluorescent fixture is almost independent of distance. Furthermore, the light from a compact bulb in a parabolic reflector is nearly independent of distance as well. "
So should be the same with MH right?
"The parabolic reflector creates parallel light rays, just like the Sun’s rays."
from:http://www.calgaryaquariumsociety.c...ght_Part_2.html
And that is what we need to get max light through panel and a clear focusable image. Hmmm wonder if you could make a parabolic reflector for a fluorex bulb? I tired that bulb, bright but light was totally uncontrolable-orderd a MH today....
:D |
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| remp |
Tinker,
People have been trying to get the best out of lighting for years. Imagine a factory. The local bylaws say there should be X amount of lighting per square foot to make comfortable working environment. If the factory or office is large there are great savings in electricity cost to be made if maximum utilisation of lamp output can be used. Same with street lighting, search and rescue lighting, airport landing lights etc etc.
You say for best results light beams should go through the LCD parallel. But how do you get parallel beams. By using point source light and reflector. Problem is point source lights are very expensive so we dont use them. That means straight away we give up option for the parallel beams and instead have to use approximate parallel beams. Approximate is not very good because only at focal point are some beams parallel. At all other light radiator area outside of focus point we have non parallel beams mixing up with parallel beams
We can look at manufactured items using 100-250 watt short arc bulbs putting very large lumens on screen but we have to use 450 watt MH bulbs to get the same thing. Sometimes takes a big struggle to even get acceptable results meantime commercial units can operate in high ambient to give a good picture.
Whats the difference. Commercial units use short arc lamps. We do not. So we have to put up with inferior reflector results.
Also there is another reason commercial units are light efficient.
Has been touched on before but no one discusses the problem.
LCD panel only works with polarised light. Half the light we give to an LCD is wasted .
Comercial projectors recycle the unused light. Change its polarisation and then use it so they are getting much better light efficiency. Recycling polarised light is not easy and not cheap, you need to intercept beam, allow correct polarisation to pass through, take incorrect polarised light pass it through a wave retarder change polarisation to correct type then pass on to LCD, so for DIY it may be impractical. But it is still a big light loss.
But even so we do pretty good.
With 400 - 450 metal halide you can be almost 100 percent sure of getting enough light even with imperfect reflector system, or even no reflector. See post by Billett.
To go to smaller wattage bulb we need to be clever. Learn more about how to use light from bulb more efficiently and give LCD good light. To do this good idea is to get raytracing software. I have downloaded reflectorcad demo version. Just starting to see how to use it. So far it seems very complicated. |
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| Tinker |
| Alright, I see. So am I nuts thinking that I can get a good pic from a 5" panel using a 150watt MH (5mm arc) projecting a 4' screen? My thought was you guys are going for like 100" so less light dispersed over area = greater brightness so my 4' screen should be useable at your half lumens light source....am I way wrong or right. Please let me know. I'm in the process of getting a 150watt bulb but will change the order if it will be totally not bright enuff. Thanks, you ahve been a big help. |
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| bixs |
Tinker
Where are you getting the bulb? 5mm arc gap sounds great. What's the cost? |
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| Tinker |
I went to dauphin electric contractor supplys and orderd one. I requested a 5mm arc gap, we'll see what I get. He said he found the bulb but had to order it as they arent a commen bulb (must be the short arc gap) I told him it was for projection so he was just going by specs I gave. Hopefully he didnt screw it up! Heres the one I was looking at:
http://www.elights.com/ven150watmet.html
See how big the center (dont know name) is where the light comes from! The bulb he showed me is similar to what I'm getting and the inner tube is like half that size. Keeping fingers crossed!:xeye: |
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| uvodee |
I truly am sorry that others don't seem to be getting their fluorex to work properly....
i can only repeat that my very very simple set up does bring the light mass together after the first fresnel, i knew that already after the first try. Therefor i am surprised that noone else seems to be able to facus that light in a sort of rectangular beam. when it enters the delta IV it is already controlled so to speak and the lens does not alter any of it's beams ....
As told before, my LOA's ( i wonder if this stands for lineair optical amplifier) are joint together pretty closely (in an angle and the front panel is actually the front panel of one (1) loa that now covers 2 loa's Indeed there is still ight going around in side the casing but less, much less than i expected. I am going to post some pics later today to show you how close the loa's are really brought together!
Jean-Pierre |
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| uvodee |
it is maybe strange to the rest of the forum but when i dismantled my lcd monitor i did not find leds of any kind of shape or form but a sort of dubble S shaped very small neon tube.
I think there lays some support of my setup. To me it is not important as to what sortof light is brought into the lcd as to how much light is brough in there and at what distance, as the original backlight fits exactly the screensize, i just focused with a fresnel the "untameable" fluorex light slightly into a rectangular and to everybody else's amazement, it turned out just fine, just as it did with Zark's (second) set up/project.
Jean-Pierre
ps i used fresnels from Office Max but i really would like to buy glass one's. A friend of mine in Belgium has tried both and says that the glass ones are an improvement |
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| Tinker |
"it is maybe strange to the rest of the forum but when i dismantled my lcd monitor i did not find leds of any kind of shape or form but a sort of dubble S shaped very small neon tube. "
Not strange at all really. Mine had the same but it was along 1/2 the rectangular frame and used a light difuser and polarising layers to disperse the light evenly. Its not a neon tube if its like mine and I think it is by your description, its a CFL. Compact flourecent light. Low heat /high lumens and low power consumption vs. output so perfect for small lcd tvs and such. Mine is a PSone mobil one interact active matrix TFT lcd panel. I removed all the polarizing sheilds and everything right down to the bare lcd itself. |
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| multiplexor |
| quote: | Originally posted by Tinker
"it is maybe strange to the rest of the forum but when i dismantled my lcd monitor i did not find leds of any kind of shape or form but a sort of dubble S shaped very small neon tube. "
Not strange at all really. Mine had the same but it was along 1/2 the rectangular frame and used a light difuser and polarising layers to disperse the light evenly. Its not a neon tube if its like mine and I think it is by your description, its a CFL. Compact flourecent light. Low heat /high lumens and low power consumption vs. output so perfect for small lcd tvs and such. Mine is a PSone mobil one interact active matrix TFT lcd panel. I removed all the polarizing sheilds and everything right down to the bare lcd itself. |
i did this to a cheap laptop about a year ago...
the flourecent bulb was very small but long. I only took one polarizer off yesterday and have been walking around looking at different objects through my one polarized broken lcd screen. Makes everything look pretty wicked i must add. :)
woneil, I have a question. I have been searching and read that you once found a 575W MH bulb for a dukane 680 OHP.
where did you find this exactly? I have a friend looking for this bulb and i'm giving him a hand.
thanks :)
If anyone else knows places to purchase 575W MH bulbs, do share :) hehe |
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| SuperZoboo |
Man, you guys have made some nice progress since I last checked the board. I especially liked the pics by DeadEye!
I feel like such a slacker. All I do is my real job (boring) and I haven't touched the projector in weeks. Of course I watch TV/Movies on the thing all the time, but as far as modifications go, none really. Problem is, I spent $180 and I love it the way it is.
When I have time I'd like to explore the custom built method, for brighter images. I'm curious how Marklar and Undream have improved their designs. I'll visit their sites' in a bit.
For those with new improvements or new designs, I'd be thrilled if you stopped by my site and submitted your specs and a link. I'd be happy to add you to my links page.
Keep up the awesome work... |
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| uvodee |
I am starting to assemble my 3rd projector.
you guys know what the elements are that i am using. This time it's for the manaager of the appartment complex, he wanted to know what all those little ups and fedex packages are that constantly are being rerouted to the office when we're not home, i showed it, he fainted and afterwards put 225 krispy klean dollar bills on the table .
I LOVE AMERICA AND IT'S PEOPLE!!!
11$ casing, 22$ lens, 9$ fresnel, 79$ lcd monitor(Legacy L56M) and $25 junk to make it look professional.
Jean-Pierre |
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| access256 |
| OK here's how it goes. My birthday was 9/12 and I had received my 400 watt MH from the inlaws!!! I immediately wired and fired it up trying to get any results. Not great. So I figured to leave it alone and spend time with them. Then I started back on the project and put aluminum foil in my light box as my "Super Parabolic Reflector" and bamm beautiful picture at 6 feet wide. But OK I had good pics with the Fluorex at 1am what about with light in the room? I turned on my two 60 watt Fluorescent lamps in the living room and 300 watts of recessed incandescent in the kitchen and a very watchable picture is there with no fine tuning of the setup yet! Then this morning at 10am during daylight and NO window covers or blinds I actually can get an image that can be seen (somewhat washed though). This is truly amazing because I just remodeled my house and my entire first floor is basically windows and with the fluorex during the day I got no usable image at all. So basically when this project is done, anytime after 5pm I should get an excellent image without shutting myself off from the rest of the world! Hopefully tonight I can take pics and post. My setup is very similar to RedDevil's but no magnifying lens after the MH yet. I still would like to get a complete glass optic condensor setup after the bulb for efficiency. More to come and Thank you all for your help it looks like this will actually work out better than I had ever imagined! |
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| jvisaria |
| Have you posted pictures of your projection yet? |
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| uvodee |
Can anyone tell me what we need in order to get a video signal (coming out of the Motorola cable box from AT&T through the female rca plug) to become a rgb signal? you know with those connectors you push and twist 90*....
(((sighhhhhhh....) |
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| uvodee |
I just came back home from a friend of mine wanting to show of his 3- crt projector. Nice 3 lenses, 2 remotes-a wireless and a wired-one. No reference of a name, i think it says Aquastar, we deducted that because some letters of a metal sticker that were left on the outer casing....
He had asked me to help him with the mounting of it...
the darn thing weighed more than a 100lbs????
What is in it??? some lead???
anyway. I left after watching about 20 minutes, i had gotten a headache, there seems to be more going on than just focussing... By the Holy Cow of Vishna.... (he's Indian)
each color needs to be somewhat angled, scanned??? and focussed and then the whole set of 3 needs to be reangled, rescanned and refocussed ... took forever AND while we were watching Black Safari(his niece plays in the movie and he is sooo proud of that!!!) , the thing went out of focus again. He claims it will be another 3 to 4 days before the machine is stabilised enough (after transportation???)
then the measurement it's about 32" by 16 by 25"
Volume wise that is bigger than the projectors i make, i know mine are lcd but still ..... one luckyy thing though, he got the darn thing for free when emptying a Seattle warehouse.
I realized that Keep It Simple may have been my luck making my own projector! |
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| uvodee |
Has anyone tried any of the Opaque projectors with an lcd monitor or screen?
i saw one this morning during a meeting... our project engineer has HIS OWN opaque , he took a colorpicture, put it under the projector and there was a 4ft picture on the wall.
it has an interesting feature, the size of the projection is determined by him as there are 2 frame sliding mechanisms.
he moves the upper and lower part of the frame in one move and the left and right side of the frame in one move, so that pictures are always tightly surrounded with a frame, leaving no extra light on the wall. Costed $150.00 according to him and was brand new, not refurbished. Looks great though brushed and black steel. |
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| Tinker |
| I built one a while back to see how they would work for our needs. Not to good Im afraid. See the light has to pass through the LCD twice this way which causes glare and some focus problems....also makes for more heat on screen. Also you need alot stronger light source for this method- the oposite of what we want. See a real image being projected the light doesnt penetrate the surface like our lcd's. With them the light is of course passing through the panels pixels. But this is now happening twice. So two times it must shut out light for black to be black and etc so it hurts the contrast ratio aswell. Twice the work, twice the light, twice the heat. You can try it, but it didnt yeild anything for me.:( :bawling: |
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| acravero |
| quote: | Originally posted by uvodee
. . . 225 krispy klean dollar bills on the table .
I LOVE AMERICA AND IT'S PEOPLE!!!
Jean-Pierre |
Uvodee--You only charged $225? Wow. It would cost that much alone just to buy the parts (once you add shipping from 5 or 6 vendors). Do you have plans or pics of this model? I've been trying to use my 5" Pyle LCD screen (very similar to the L56M), without too much luck figuring out lenses and such. If you have a parts list and/or plans that you'd be willing to share, please let me know.
Thanks,
Anthony |
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| uvodee |
for those who are trying to use the nec 6448AC33-18 lcd without any luck to find the right set up between lcd and vga card (or svga) , it am not 100 pct sure but i think strongly that the SHARP LQ10D32A is exactly the same 10.4 " display after comparing tecnical notes and data sheets.
Apperently the whole set without the display can left and right be bought for less than $200.
the NEC display has been for sale on ebay for $0.01 and the woman said she had 100s . That was some 2 months ago i think.
Anyway maybe for those it can be of any help i think that earthlcd sells the kits.
I did notice that the the amount of colors does not run in the million so i think that is kind a weak....
i should have known that those lcd panels came from one factory !!!!!!!!!!
Jean-Pierre |
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| uvodee |
the pyle and legacy i think are basically very much the same.
(there are 3 more that are similar but i can't think of the name right now) but i think you bought your's at 'Judy's" right???
if you pay more than $70 for this stuff you are being robbed!
they go for $25 (each) back in their homeland! |
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| acravero |
| quote: | Originally posted by uvodee
the pyle and legacy i think are basically very much the same.
(there are 3 more that are similar but i can't think of the name right now) but i think you bought your's at 'Judy's" right???
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Uvodee--
Paid 80 for it, and can't remember where I bought it. Some shop that auctioned it on ebay. It's not a bad little screen, but it may be time to move on, in which case this one would make the perfect project screen.
Would you mind sending me your plans? I would gladly reimburse you, particularly if you have good places to buy everything. At this point, I'm still toying with the idea of buying a prefabbed used projector. Other than building computers and rewiring my electric guitars, I don't have too much experience, and the more I read, the more this all seems over my head.
Also, does anyone have the pinout for the PLVWM 5.0" pyle panel's adapter? It comes with a "serial" style connector that provides the video signal & the power, and I'd like to leave it in-tact, if possible. It is a 6 pin (+ 1 "plastic" pin) DIN format. Is this standard?
Also, what type of lens should I get--I was going to get a Delta IV, but I've read that's not the best bet. Is the Fujinon from the military surplus store more "flat"? Sorry to sound so unintelligent about the topic, but I just started reading through the numerous posts here...
Thanks,
Anthony |
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| uvodee |
all my plans/pics are in Yahoo groups, lcdprojector under photo's and then click on jpsprojector.
mine is a but different than most others, it takes too much time to explain. let's just say that you need to read all older messages and after that think i am the 'enfant terrible' on this board, which is ok, i have a very lovin' wife! hahahahhahahh
any more questions about my project , just ask or alos you can go to zark's website! simplicity in itself. |
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| pyro139 |
first this forum is great just started reading yesterday was doing research on hooking a small lcd to a svga card and found this now i want to build one.
can any one give me a straight forward link to plans for one
my idea iis to recycle my old dark room enlarger has all the basic parts and lamps are cheap like $60 a bulb or may replace with leds but need full specs on how to configure and also
any one know how to propaly conect the lcd to s-vga if not rca would do my radeon card does have rca and s-video so not brob but would love s-vga:) |
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| pyro139 |
forgot by useing enlarger gives me a bellow focused lens with apature adjustment:) (can adjust amount of light thru lens)
and lens are interchangeable so can switch lenses and light allowance depending on different enviroments |
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| biteon |
yo i did so many thing and got so close . i think the most i could pull out of the 400w mh was when i funnelled the light but of couse that cause blurry edges on my projected movie. im out of ideas for the 400w mh except for one more very last atempt.thats to make a lens big enough to catch all the light coming from the 1/2 spheare reflector. the idea to make the lenscame from one of those glass water balls with snow flakes (they act like a lens to) i was thinking of using a flat peice of glass on one side than using a warped peice of plex-E glass on the other side.then glueing then to getter.then drilling a hole at the top of the lens to stick a hoes in so i can fill the lens with water. the hoes will also act as something to releave the pressure from the hot water.maybe i'll have the hose runing out of the projector box. also some other thing about this lens,is the water will act as a ir filter, temper glass can handel more heat , i'll probly use a heat gun to form the plex-E glass, and most of all this water lens can be very dangrous if leaks or breaks.
if that dont work im selling my light. and i might quit this project, or buy a broken projector and fix it, and or i might do what undreem was talking about doing and getting a 1000w mh. i think his thorey is correct and then the only potential problem we'll probly have is the cooling system and the wiring of a saftey plan so if the fans or what ever cooling sys. goes out the light will turn off to/ so theres not a melt down or a fire in the house.
"And thats all i got to say about that".(forest gump)
:D :D :D :D |
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| uvodee |
gee, the only problem you are facing is the lens and you do not wish to go ahead?
1) i went against all odds and used the fluorex
2) i used 1 plastic fresnel
3) against all odds i used a delta IV or 67 depending my feeling
4) i had to overcome so many problems by using the cheapest lcd on the market ( had to connect 50 pos. spread over three wires ( i had to keep them the same length and they could not exceed a certain lenght ( 5" ) otherwise NO PICTURE
and still i went on and succeeded! come on maaaaaaaaan. |
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| jco9w |
uvodee-
I don't really know whether your projector works because you have not posted a screenshot yet. I asked you for one a long time ago, but you never put one up. I have serious doubts about the flourex setup, especially with so many people saying they couldn't make it work.
I managed to snag a 3M 9550 off of ebay, and that is the final piece I need. I am going to use the optics directly from the OHP (which are matched to one another) and my 400 W MH bulb with my elliptical downlight reflector. Hopefully I will have it going in a few days, depending on how much time I can put in.
J |
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| slikk |
jco9w
where did you get your elliptical reflector? Can you get us a pix of it? I'm putting together a similar setup as you with my 3m ohp and 400 MH ed28 bulb.
Thanks |
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| jco9w |
Hi-
I got really lucky. I found an elliptical downlight on Ebay a couple of months ago. I picked it up for $20. I don't really have any leads on where to get one for people, unfortunately. Keep looking on ebay though, they do sometimes show up.
J |
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| Tinker |
| Lowes and Home depot have light cans for MH track lighting. Some of those are eliptical. Go with one though deseigned for spot lighting or spot track lighting. These give a much nicer narrower beam like 10-20o. More is aimed at the panel that way. |
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| Tinker |
| quote: | Originally posted by uvodee
gee, the only problem you are facing is the lens and you do not wish to go ahead?
1) i went against all odds and used the fluorex
2) i used 1 plastic fresnel
3) against all odds i used a delta IV or 67 depending my feeling
4) i had to overcome so many problems by using the cheapest lcd on the market ( had to connect 50 pos. spread over three wires ( i had to keep them the same length and they could not exceed a certain lenght ( 5" ) otherwise NO PICTURE
and still i went on and succeeded! come on maaaaaaaaan. |
I too only use one fres. I have 3 BUT the pic gets birght in the middle and dimm at the edges when I usemore than one. Just one before the lcd has given me the best pic. |
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| slikk |
Thanks Tinker.
I'll go to a local HomeDepot this weekend and see what I can find. Lowes is a bit too far for me. |
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| uvodee |
well in all honesty, it (they) work really well)
the reason why I did not post any pic of the projection is i do not get any picture taken from the result i guessthe camera i am using AIPTEK pencamera is not suitable for this kind of dark situations at the amse time i took the camera with me to a movie theatre at gateway center in Federal Way and it did not work there as well ...
i am trying to find a solution with some better camera... |
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| uvodee |
| can someone here tell me why the luoisville edu link does not work anymore? |
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| biteon |
ithink i no a way to use all the light from a bulb and send all of that light striat in a paralel beam. no reflector needed . do you want to no about it. it will need a crazy cooling system, thats the only down side. no i have not tryed it but logicaly it look to me it will work. it will take some time for me to draw it out in 3d so you guys can under stand how it works. so unless some one wants to know im not gona bother telling or drawing it. i have a feeling nasa would hire me just because of this idea.lol.
i have no money to test it out etheir.
:D :D :D :D |
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| Tinker |
| Well, come on of course we want to know. This site is all about sharing ideas. ;) |
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| Gunawan W |
Hi Guys,
You all know that the LCD panel itself swallow lot of light from the lamp, but could you figure out how much is it? I mean before LCD panel put in place the projected light brightness at the screen = 100%, then after the LCD panel in place reduce to = ...%. It will help to choose the lamp power.
thank you. |
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| multiplexor |
If i remember correctly, I think only 15% will get through. So 85% of the light is loss.
Can someone confirm this number? I know it's a heck of a lot which is lost.
edit: had 75% up there instead of 85... woops :) |
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| Tinker |
I heard 10. But I think it varies too. I'm sure it prob. goes as high as 15% on TFT but those poly ones or whatever its much higher. There are dif ways that they make the color pixels. Die is one way, ink impregneted gel another, yadda yadda. But anyhow yes it is low. Also only 50% of your light is even accepted by the panel. Even less gets passed on... Two polarizations. P1 and P2. P2 is absorbed by the panels polarizer. P1 is passed on and viewed. Your light source is 50% P1 and 50% P2. This is what light recycling is about. Converting or getting some of the P2 to change to P1 then pass back through the panel this time accepted as P1 and some again rejected as P2. By a small portion each time P1 comes back. Then in other ways its a pure convertion too. Theres alot more to it also but, well Id get tired of typing I think. hehe.
Someone here, dont remember who. Said that if you hold a panel up to the light that what you see is as black as the panel can get (contrast). Thats wrong I think??, after alot of reading about lcd tech lately. The pixels cut off light by the crystals twisting the angle of light thus the last filter after lcd film cuts out light making it black. How quickly the light can be stopped by this method of twisting due to several limitations is the result of the contrast ratio. So the quicker it cuts out the light the blacker it apears. Also the quicker it can iluminate aswell of course. This is how i understand it. Anyone else got somthing on it?:confused: I wanna make sure its right..... |
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| uvodee |
See, that is when i get troubled..... with statements that the light gets sucked up and energy gets lost.
i have seen projectors consuming less than 275 watts (and that means including amp (sound) fan (cooling) panel (display( and then light bulb(s) ...... ( light bulb of 200 watts or less is not uncommon in lcd projectors)*******
if these displays were to stop between 75 and 85 pct then ALL the stories here about a 400 W MH should be a success but they aren't instead non polarized light such as fluorescent and less than half of that succceeds.
see tinker something somewhere is wrong here. I cannot explain
a) i am not such a technical bozo
b) my english is far from perfect ...
but maybe, maybe someone sees the light here and does know why this goes and that doesn't.
******** same with ohp's some bulbs less than 275 watts seem to give enough output to have more than descent results.
i want to remind some of you on this forum that some guy started an interesting line here : car lights (like the one on chevy's from the early 80's you know the sylvania rectangular type that you can buy for less than $15. The bulb is a nonreplaceable type glued inside a holder . more important the bulb is mounted horizontally and the reflector is a perfect match.
I AM GOING TO DO THE TEST and replace the 2 fluorex with one of those lamps, this is easy for me due to relative simple set up and the powersupply already inthe casing. see what result this gives. |
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| Tinker |
| quote: | Originally posted by uvodee
See, that is when i get troubled..... with statements that the light gets sucked up and energy gets lost.
"i have seen projectors consuming less than 275 watts (and that means including amp (sound) fan (cooling) panel (display( and then light bulb(s) ...... ( light bulb of 200 watts or less is not uncommon in lcd projectors)*******
if these displays were to stop between 75 and 85 pct then ALL the stories here about a 400 W MH should be a success"
It is true that 50% of the light isnt used. Ive been looking into this very heavily as of lately. The reason low watts are used on modern projectors is because they RECYCLE the light. the tunr that 50% unusable lgith into P1 that is usable with a 1/4 wave filter and etc. I can go more into detail, but alas they do loose 50% UNLESS this is done. Thus a 400watt un recycled light source is only 200watts to the panel. A comercial (boughten) LCD projector uses light recycling tech and gets like 200watts from 250 or even better to the lcd. When I say 50% is lost I mean with the methods most are using here. Not in comercial units.
" but they aren't instead non polarized light such as fluorescent and less than half of that succceeds."
HUH? No, all light is polarised and more specifically it has two polaritys defined as P1 and p2. Flourescent has nothing over MH in that way I assure you. And I have the flourex bulb...it was way too dim. I got my 175 watt MH finally and its 10x brighter and really cool compared to my halogen at 90watts. And the projected image is far better than my flourex bulb gave. That bulb is huge and all the light is far from available when using it. Its also too large of a source to get into focus with a lens also. With MH its all in the reflector (and or condensor lens) but me and somebody else (top secret..hehe) are working on light recycling. Its now more important then ever to get a decent reflector as this is where the P1 is changed to P2 through difraction.. I have some samples of stuff to try (lcd film tech), let you know what I get with my experiments on it.
see tinker something somewhere is wrong here. I cannot explain
a) i am not such a technical bozo
b) my english is far from perfect ...
but maybe, maybe someone sees the light here and does know why this goes and that doesn't.
******** same with ohp's some bulbs less than 275 watts seem to give enough output to have more than descent results.
i want to remind some of you on this forum that some guy started an interesting line here : car lights (like the one on chevy's from the early 80's you know the sylvania rectangular type that you can buy for less than $15. The bulb is a nonreplaceable type glued inside a holder . more important the bulb is mounted horizontally and the reflector is a perfect match.
I AM GOING TO DO THE TEST and replace the 2 fluorex with one of those lamps, this is easy for me due to relative simple set up and the powersupply already inthe casing. see what result this gives. |
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| Tinker |
By the way when one says the lgiht is polarzed they mean that one polarity has been filtered out or converted. Like only P1 light passed and P2 absorbed (LCD panel does this very thing)or reflected (birefringent film or prism) or P1 and P2 converted to P1 then reflected back with a prism film or 1/4 wave plate.
So polarized light means one polarity ither removed in one way or another. LCD panels only use P1 look at any lcd tech site (like that "how things work" site which is really good by the way). P2 is absorbed and whe the polarizer film wears eventually out you get blurred pics.:( |
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| Tinker |
| Actually here I'll prove it to ya once to help you understand it. Use your lens to focus your light source into a little spot as small as posible (f1) then place your hand or white paper in the lgiht path. See how bright and intense it is. Now take your lcd panel and place it between the lens and light like usual. Find f1 with this setup and it focused. It will still be the same distance as before BUT the light beam will now be ALOT dimmer. This is how much your panel is loseing. Oh yeah and make sure the panel is on when doing this. I've done this and there is a HUGE dif. The panel eats up alot fo light thats is for sure. Alot more is lost do to polarity aswell. |
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| remp |
As Tinker has said light polarization is important.
Ordinary light sources such as Haloden or Metal halide are randomly polarized. Half the light power is in the P polarization. Half the light is in the S polarization.
LCD panels use P polarized light. Or S polarised light. One or the other but not both.
That means that the panel can only use the P polarized light and the S polarized light is absorbed as heat by the first polarizer.
Therefore LCD panels use only 50 percent light of the original light.
If the panel looses 90 percent of the source light it gets, it would be twice as bright if we could arrange all the light from the source to be P polarized. That is possible. 3 panel projectors do this.
Just how possible and practical and economical it is for DIY people is a question to be anwered. Maybe someone does these experiments.
But it is an important question because
Instead of using a 450 watt Metal halide we could use 250 Watt. Smaller bulb, smaller ballast, easier reflector, less heat, less fan noise and use less electricity. Maybe also cheaper bulb/ballast.
This is an idealised situation. It may not be economical to try and get all the light going through the LCD but even 80 percent would be a good advantage.
With only light of the correct polarization hitting the LCD, the first polarizer has far less work to do so does not heat up and does not dim your picture as time goes by. |
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| uvodee |
i can admit that i am wrong. I was told that only great minds change their judgements about things.
but where am i wrong? why does the lfuorex succeed with me while being completely out of the range of theories that are proclaimed here..... i really would like to know. Why is it that with brute power and the 2 fluorexes some one and a half inch away from one fresnel and another inch from the lcd panel followed by one inch of spacing and than a delta IV lens the picture projected is more than descent! i would really want to say pretty darn good!
i read here of washing colors away, daze, haze, screen door effect, those things do not seem to exist in this set up ? why is that?
the 16/9 i get by pulling my box back , when playing this format so that the projected picure covers the screen completely ( i made it in 16/9 format from the beginning) again, something so easy........ i have no special lcd 16/9 but i know that when playing a widescreen dvd on my extremely cheap Mintek dvd player trhough the lcd, i get a widescreen result that does give me the whole screen.
see this are some of the things that bother me ..
further more Nobody has answered my question on 16/9 being a format completely against nature and mankind... ===sighhhhhhhh===
i really wish someone would help me understand why when i do something completely wrong, the results are positive! ! ! ! ! |
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| multiplexor |
| quote: | Originally posted by uvodee
i can admit that i am wrong. I was told that only great minds change their judgements about things.
but where am i wrong? why does the lfuorex succeed with me while being completely out of the range of theories that are proclaimed here..... i really would like to know. Why is it that with brute power and the 2 fluorexes some one and a half inch away from one fresnel and another inch from the lcd panel followed by one inch of spacing and than a delta IV lens the picture projected is more than descent! i would really want to say pretty darn good!
i read here of washing colors away, daze, haze, screen door effect, those things do not seem to exist in this set up ? why is that?
the 16/9 i get by pulling my box back , when playing this format so that the projected picure covers the screen completely ( i made it in 16/9 format from |
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