Thanks for getting things going again, Joe! It's good to see some new names/fresh ideas here, too. It looks like I am going to be looking or a new light source just as some others are, because I think the LOA (non-point-source) light is causing problems with my image.
I received my nView Viewframe Spectra C from Inventory Solutions yesterday, and I have spent about an hour playing with different configurations---all of which have resulted in blurry edges. I was using the LOA 65w Fluorex light------>the LCD panel------->lens.
The three lenses I have played with are an Office Depot page magnifier fresnel, the Fujinon Projection lens from Surplus Shed, and a 10cm diameter double convex lens, also from Surplus Shed (it has a focal length of 20cm). I also tried the fresnel before the LCD with the DCX lens after to mimic an OHP setup. I always got blurry edges, and the DCX isn't large enough to project the entire image anyway.
Does anyone know if the projection lens on an OHP is a double convex lens or an achromat lens? I will probably just decide to dismantle an OHP and use the parts if I can't find a combination that works. I would post images, but they are honestly not watchable at this point.
BTW, the LCD panel I have is a 640x480 unit with s-video, composite, and VGA inputs. It seems to be a nice unit, and I am fine with the resolution. I have taken it apart (of course!) and the panel itself is easily movable for positioning options. The fans are noisy, though, so I might look for a nice computer fan.
Sorry to ramble. Good luck everyone.
-f4
I received my nView Viewframe Spectra C from Inventory Solutions yesterday, and I have spent about an hour playing with different configurations---all of which have resulted in blurry edges. I was using the LOA 65w Fluorex light------>the LCD panel------->lens.
The three lenses I have played with are an Office Depot page magnifier fresnel, the Fujinon Projection lens from Surplus Shed, and a 10cm diameter double convex lens, also from Surplus Shed (it has a focal length of 20cm). I also tried the fresnel before the LCD with the DCX lens after to mimic an OHP setup. I always got blurry edges, and the DCX isn't large enough to project the entire image anyway.
Does anyone know if the projection lens on an OHP is a double convex lens or an achromat lens? I will probably just decide to dismantle an OHP and use the parts if I can't find a combination that works. I would post images, but they are honestly not watchable at this point.
BTW, the LCD panel I have is a 640x480 unit with s-video, composite, and VGA inputs. It seems to be a nice unit, and I am fine with the resolution. I have taken it apart (of course!) and the panel itself is easily movable for positioning options. The fans are noisy, though, so I might look for a nice computer fan.
Sorry to ramble. Good luck everyone.
-f4
Well this is my first post here I found this site this morning and I got to page 20 and said ok im not reading the rest right now my eyes are tired. I have been wanting to build a projector for some time now and i did make one out of a 19" TV about 2 months ago but it was to dim and I have been trying to figure out how to make it work. As for a light source I dont know if anyone has said this but I was at home depot today and saw a florecent dusk to dawn light that puts out 7000 lumens and I figure with a reflector that would be more than enough light but I didnt buy it yet because I was wandering is there a such thing as to much light? They also has a smaller flood like that was 2500 lumens both lights were very inexpensive the 7000 lumen one was $35 and the small one was $25 and they dont get near as hot as a halogen and last many years the bulbs only cost around $13 they do have a small electronic ballast that does produce little heat. I have found a great surplus site that has many lenses and LCD screens Im waiting for a reply from one of the sales man to see if he has some good LCDs. I have found Delta 77 lenses on that site for $12.50 these are the same lenses used on high quality big screen projection TVs. I will hopefully start my project soon and keep yall posted with lots of pics. Please let me know if there is a such thing as to much light.
Oh yea Im in the construction and you can get windows that are called Low-E that reflect heat they work quiet well I saw a test setup at home depot where they had a 150W flood behind normal glass and one behind the Low-E glass and I could tell the difference, and this glass isnt very expensive at all.
Marklar,
Welcome to the board. This thread IS very long, but it worth taking the time to read it...lots to be learned from others' successes and failures.
The fluorescent light you mentioned is probably similar to the light I mentioned in the post before yours. Mine is made by Lights of America (LOA) and it does produce a good bit of light. The only problem is that it is not a "point-source" light, meaning that the light is produced throughout the length of the bulb as opposed to a metal halide bulb that has its source of light in a very concentrated area. The LOA seems to wash out the image because of rays from different angles (from different "sources") striking the LCD. This is minimized with a point-source light.
Thanks for the tip on the low-e glass. It sounds like it reflects the IR spectrum.
-f4
Welcome to the board. This thread IS very long, but it worth taking the time to read it...lots to be learned from others' successes and failures.
The fluorescent light you mentioned is probably similar to the light I mentioned in the post before yours. Mine is made by Lights of America (LOA) and it does produce a good bit of light. The only problem is that it is not a "point-source" light, meaning that the light is produced throughout the length of the bulb as opposed to a metal halide bulb that has its source of light in a very concentrated area. The LOA seems to wash out the image because of rays from different angles (from different "sources") striking the LCD. This is minimized with a point-source light.
Thanks for the tip on the low-e glass. It sounds like it reflects the IR spectrum.
-f4
Joe, regarding the lenses of OHPs, i have 2 OHPs, one of them has 3-lens system, the other 2 lenses. Most objectives have more than 1 lens to compensate the image distortion of only a single lens. The more convex a single lens, the shorter the focal length and the more distortion.
I'm too searching for another lens-system, the best would be zoom-objective between 290- 320mm, cause my projector is standing in the middle of my room now, making 110" image size. But it's hard to find this!
I would recommand the guys, who go the LCD-route:
Bid on OHPs and Projection-panels ! OHPs over 5000 lumens will make nice images. Then you will have no probs with melted fresnels, cooling, lightsources, optics, broken ribbons, pcbs....!
This can be cheaper and less annoying.
I've paid about 400 EUR for both.
And if you say, but it's fun, you'll have enough work to built a DIY-screen!!
That's what i'm doing actually !
Cheers
xblocker
I'm too searching for another lens-system, the best would be zoom-objective between 290- 320mm, cause my projector is standing in the middle of my room now, making 110" image size. But it's hard to find this!
I would recommand the guys, who go the LCD-route:
Bid on OHPs and Projection-panels ! OHPs over 5000 lumens will make nice images. Then you will have no probs with melted fresnels, cooling, lightsources, optics, broken ribbons, pcbs....!
This can be cheaper and less annoying.
I've paid about 400 EUR for both.
And if you say, but it's fun, you'll have enough work to built a DIY-screen!!
That's what i'm doing actually !
Cheers
xblocker
Comments
I think the metal halide "fish tank" light is the best choice for those doing DIY light source for a LCD panel.
Otherwise, as previously suggested, get to know your OHPs and get a good quality one, >4K lumens. There's a HP-A305 (7K lumen, MH) on ebay now for $150, from our friends at Inventory Solutions...
From what I've read on the web, lens quality goes up with projector "quality" - which usually means lumens output. So even if you're going to DIY the light source, get the lens from a good quality, albeit dead OHP.
Watching the VP140 with a DVD movie, well the Nview Z350 isnt even close, on neither color rendition nor response. So you can get projection panels, but I suspect that the technology "generation" of the LCDs in these isnt up to what's pretty ordinary in the last few years in monitors.
That's why I have smug thoughts in passing on that $350 Proxima panel. It may have the same color capability, but I bet it doesnt respond as fast as the VP140. At a 10" diagonal, it would let about 1/2 the light through of a 14" diagonal unit.
My hopes are;
1. that I can solve the cable problem and it still works.
2. that I can get the brightness/contrast adjusted for a decent looking image.
3. That I can package the PCBs and LCD so they dont get destroyed before I get a chance to enjoy the unit.
Later!
I think the metal halide "fish tank" light is the best choice for those doing DIY light source for a LCD panel.
Otherwise, as previously suggested, get to know your OHPs and get a good quality one, >4K lumens. There's a HP-A305 (7K lumen, MH) on ebay now for $150, from our friends at Inventory Solutions...
From what I've read on the web, lens quality goes up with projector "quality" - which usually means lumens output. So even if you're going to DIY the light source, get the lens from a good quality, albeit dead OHP.
Watching the VP140 with a DVD movie, well the Nview Z350 isnt even close, on neither color rendition nor response. So you can get projection panels, but I suspect that the technology "generation" of the LCDs in these isnt up to what's pretty ordinary in the last few years in monitors.
That's why I have smug thoughts in passing on that $350 Proxima panel. It may have the same color capability, but I bet it doesnt respond as fast as the VP140. At a 10" diagonal, it would let about 1/2 the light through of a 14" diagonal unit.
My hopes are;
1. that I can solve the cable problem and it still works.
2. that I can get the brightness/contrast adjusted for a decent looking image.
3. That I can package the PCBs and LCD so they dont get destroyed before I get a chance to enjoy the unit.
Later!
CRAP! they have to send the xenon light back to Sydney for the warranty guys to investigate it...i wonder if I can "make" another one defectable 🙂
just a quick question...everyone who has got to the stage of a viewable picture, what size screen are you projecting? since i really only have room for about 80 inches, i suppose i don't really HAVE to get the highest (most expensive) resolution lcd screen, right?? (i'm after a ovation 820)
just a quick question...everyone who has got to the stage of a viewable picture, what size screen are you projecting? since i really only have room for about 80 inches, i suppose i don't really HAVE to get the highest (most expensive) resolution lcd screen, right?? (i'm after a ovation 820)
Gav
I have a proxima ovation 810 panel which works really well at about 60inches screen. I haven't really tried bigger. The panel is great with DVDs. In my experience on a DIY system 640x480 is fine for whatever you are displaying. I hope to post some pictures within a couple of weeks.
To everyone else looking for a light source I mentioned this a long time ago. Try a EVD OHP halogen bulb. You should be able to get one for sub £10/$10. They produce a very bright light up to 5000 lumens. I'm not an electronics expert but I think a standard power supply should power one. These should be more pointlike compared to the other stuff people are trying (except MH). One decent fan should be enough to cool one of these.
Good Luck
Andy
p.s. not an april fools joke this time (-:
I have a proxima ovation 810 panel which works really well at about 60inches screen. I haven't really tried bigger. The panel is great with DVDs. In my experience on a DIY system 640x480 is fine for whatever you are displaying. I hope to post some pictures within a couple of weeks.
To everyone else looking for a light source I mentioned this a long time ago. Try a EVD OHP halogen bulb. You should be able to get one for sub £10/$10. They produce a very bright light up to 5000 lumens. I'm not an electronics expert but I think a standard power supply should power one. These should be more pointlike compared to the other stuff people are trying (except MH). One decent fan should be enough to cool one of these.
Good Luck
Andy
p.s. not an april fools joke this time (-:
VP140
I've read this thread page by page last weekend, and it has helped me quite a bit. but, since i have read it, i know how many ppl say this exact thing, so ill get to the point...
right now im using an nView Spectra C with an overhead from office depot (they have a nice return policy, and i wanted to test a 3000 lumen before i bought one for sure). it works REALLY well, but i would like higher resolution. i noticed ppl talking about the viewsonic VP140, but i can only find it for over $400. this seems pretty high. is there another viable solution for cheaper? i could get a high res projection panel off ebay for much much cheaper.
plus, for all you ppl messing with color settings and such, get powerstrip. it gives you full control over all color, brightness, etc... settings. since it controls your video card directly, it even affects overlays. (dvd, anything that uses a hardware accelorator, games, etc...). great tool, plus you can set it up for hotkeys to quickly switch from different resolution/color settings, with one click. its free too.
also, im going to rig this current overhead projector with an LOA. i figured, why not BUY an expensive OHP, when i can just modify a current one to be bright. most OHP's have enough room to play around, and you could put 2 of these in there if you were creative. i just dont like the heat that the OHP produces, and the noise would be a nice thing to remove, even though with a movie on, you dont notice.
I've read this thread page by page last weekend, and it has helped me quite a bit. but, since i have read it, i know how many ppl say this exact thing, so ill get to the point...
right now im using an nView Spectra C with an overhead from office depot (they have a nice return policy, and i wanted to test a 3000 lumen before i bought one for sure). it works REALLY well, but i would like higher resolution. i noticed ppl talking about the viewsonic VP140, but i can only find it for over $400. this seems pretty high. is there another viable solution for cheaper? i could get a high res projection panel off ebay for much much cheaper.
plus, for all you ppl messing with color settings and such, get powerstrip. it gives you full control over all color, brightness, etc... settings. since it controls your video card directly, it even affects overlays. (dvd, anything that uses a hardware accelorator, games, etc...). great tool, plus you can set it up for hotkeys to quickly switch from different resolution/color settings, with one click. its free too.
also, im going to rig this current overhead projector with an LOA. i figured, why not BUY an expensive OHP, when i can just modify a current one to be bright. most OHP's have enough room to play around, and you could put 2 of these in there if you were creative. i just dont like the heat that the OHP produces, and the noise would be a nice thing to remove, even though with a movie on, you dont notice.
My Plan
Well I have decided to go the easy way. Why try to reinvent the wheel when you can go buy one real cheap? So far I have found 65 watt 7000 lumen florolux lights at home depot you can either buy the lamps and ballest seprate or you can just buy the whole light if your not sure what kind of ballest to get. The whole light can be bought for $35 each at home depot heres a link direct to the fixture Home Depot . I am going to go with a proven design and used a standard overhead projector these can be bought off of ebay for under $50 for a real nice unit. It doesn't matter what kind of light output it has because it will all be removed just make sure all the lenses are clean and not all scratched up. The other major part is the display many people I see are using regular LCD displays well I don't mean to sound like an *** or anything but most LCDs are not made for this so why use them? Thats why Im going with the regular LCD display made to work with an overhead projector. I just got 2 for $80 on E-bay with s-video, composite, and vga inputs with a 640X480 resolution and it even has a nifty remote to adjust all the levels. So here we are $200 later, open the OHP and rip the guts out of it, fan and all, the new lights burn cool and electronic ballasts don't put off hardly any heatso theres no reason for a loud fan. Just look at the drawings I made its real easy to follow. that last thing that I was trying to figure out was "DAMN IT that thing shines so much light out the top it lights the whole room well get a thick cloth and glue it to the bottom of the head makeing sure the head can still easly be adjusted and its not blocking the lenses, WOW problem solved. I have seen the regular projectors and LCDs in action when i was in school but the bulb life sucked, it made alot of noise, and it lit the room up. Well hopefully this will fix those problems. I hope to have a fully working proto type in a week or so and i will get lots of pix my digi cam, it owns you. 😛
Well I have decided to go the easy way. Why try to reinvent the wheel when you can go buy one real cheap? So far I have found 65 watt 7000 lumen florolux lights at home depot you can either buy the lamps and ballest seprate or you can just buy the whole light if your not sure what kind of ballest to get. The whole light can be bought for $35 each at home depot heres a link direct to the fixture Home Depot . I am going to go with a proven design and used a standard overhead projector these can be bought off of ebay for under $50 for a real nice unit. It doesn't matter what kind of light output it has because it will all be removed just make sure all the lenses are clean and not all scratched up. The other major part is the display many people I see are using regular LCD displays well I don't mean to sound like an *** or anything but most LCDs are not made for this so why use them? Thats why Im going with the regular LCD display made to work with an overhead projector. I just got 2 for $80 on E-bay with s-video, composite, and vga inputs with a 640X480 resolution and it even has a nifty remote to adjust all the levels. So here we are $200 later, open the OHP and rip the guts out of it, fan and all, the new lights burn cool and electronic ballasts don't put off hardly any heatso theres no reason for a loud fan. Just look at the drawings I made its real easy to follow. that last thing that I was trying to figure out was "DAMN IT that thing shines so much light out the top it lights the whole room well get a thick cloth and glue it to the bottom of the head makeing sure the head can still easly be adjusted and its not blocking the lenses, WOW problem solved. I have seen the regular projectors and LCDs in action when i was in school but the bulb life sucked, it made alot of noise, and it lit the room up. Well hopefully this will fix those problems. I hope to have a fully working proto type in a week or so and i will get lots of pix my digi cam, it owns you. 😛
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Quick Question..
would something like this work? I sketched it up. I read the first ~30 pages or so of this thread, and could hardly bear the fact that people were slowly giving up with the LED's. I really think if you could condense as much of that light as possible, using something more than just 45 degree mirrors, it just might be possible. Then, I thought about telescopes -- and how they use Parabolic mirrors to amplify faint light, and I just had to do this sketch. If I am completely stupid, then, let me know. I've just been really excited about it since I found this thread. I'm very impressed with what is going on here. Even if this design needed 100, or 150 LEDs, it would still be more cost-effective, quieter, cooler, and just plain ingenius over using standard halogens.
I'd love to hear comments.
Parabolic mirrors can get expensive as you go up in size. I've seen a 4.5" for $36, a 6" for $49, and an 8" for about 90. 10" + are usually used for high-end telescopes, and they are usually only produced with extremely high quality, and hence, are super expensive (hundreds)
would something like this work? I sketched it up. I read the first ~30 pages or so of this thread, and could hardly bear the fact that people were slowly giving up with the LED's. I really think if you could condense as much of that light as possible, using something more than just 45 degree mirrors, it just might be possible. Then, I thought about telescopes -- and how they use Parabolic mirrors to amplify faint light, and I just had to do this sketch. If I am completely stupid, then, let me know. I've just been really excited about it since I found this thread. I'm very impressed with what is going on here. Even if this design needed 100, or 150 LEDs, it would still be more cost-effective, quieter, cooler, and just plain ingenius over using standard halogens.
I'd love to hear comments.
An externally hosted image should be here but it was not working when we last tested it.
Parabolic mirrors can get expensive as you go up in size. I've seen a 4.5" for $36, a 6" for $49, and an 8" for about 90. 10" + are usually used for high-end telescopes, and they are usually only produced with extremely high quality, and hence, are super expensive (hundreds)
Hrmm..
Well, when I said $50 for a 6" parabolic mirror, I must have been on crack. I did find a 4.5" one for $36, but it was an f8, which means the focal length is 4.5*8 = 36 inches. thats just too far for a normal projector enclosure. especially when you only have 4.5" diameter of LED circuit board to work with. A 6" f4 would probably be the smallest focal length parabolic telescope mirror that you could actually use -- and they start at about $99, and you might be able to E-bay one for about $80. Even then, you need 24" between the mirror and the lens positioned at the focal point -- and of course, the LEDs would have to be slightly further than that, as to not interfere with the focal point collection of light. Ideally, I would use a 8" with about a f2.5 focal length (20 inches). Good luck finding one of those. Even if you did, it would probably be near $200.
Plan B.
I'm not too sure if they would be good enough, but I found a 12" parabolic aluminum reflecting surface Here
If that would work, not only would it be CHEAP, but you would have tons of room to work with the LED's. And the beauty of it is, it doesn't matter where you put those LEDs directly across from the reflective surface, because the light will be reflected back to that focal point. I would really like to see what they are capable of. For $29.95, that would be an awesome solution.
Well, when I said $50 for a 6" parabolic mirror, I must have been on crack. I did find a 4.5" one for $36, but it was an f8, which means the focal length is 4.5*8 = 36 inches. thats just too far for a normal projector enclosure. especially when you only have 4.5" diameter of LED circuit board to work with. A 6" f4 would probably be the smallest focal length parabolic telescope mirror that you could actually use -- and they start at about $99, and you might be able to E-bay one for about $80. Even then, you need 24" between the mirror and the lens positioned at the focal point -- and of course, the LEDs would have to be slightly further than that, as to not interfere with the focal point collection of light. Ideally, I would use a 8" with about a f2.5 focal length (20 inches). Good luck finding one of those. Even if you did, it would probably be near $200.
Plan B.
I'm not too sure if they would be good enough, but I found a 12" parabolic aluminum reflecting surface Here
If that would work, not only would it be CHEAP, but you would have tons of room to work with the LED's. And the beauty of it is, it doesn't matter where you put those LEDs directly across from the reflective surface, because the light will be reflected back to that focal point. I would really like to see what they are capable of. For $29.95, that would be an awesome solution.
oh yeah
the focal length on that 12" diameter aluminum reflector is only 3". That would make things very tight within the casing!
the focal length on that 12" diameter aluminum reflector is only 3". That would make things very tight within the casing!
Parabolic mirror
undream
I was interested in building a high power telescop a long time ago and found in a book how to make a high precision parabolic mirror. This was not expensive as far as I can remember.
I think You use a thick glass from a boat (from the port hole) and polich it to the right specs. Then You coat it whith silver oxide I think.
This maybe sounds complicated but I do not think so becouse it was intended for beginners.
This way You can do a parabolic mirror any size You want!
Bye for now
undream
I was interested in building a high power telescop a long time ago and found in a book how to make a high precision parabolic mirror. This was not expensive as far as I can remember.
I think You use a thick glass from a boat (from the port hole) and polich it to the right specs. Then You coat it whith silver oxide I think.
This maybe sounds complicated but I do not think so becouse it was intended for beginners.
This way You can do a parabolic mirror any size You want!
Bye for now
lenses
fender4,
I did some experiment using Delta 20 Proj. lens (part # L1813) and Plano convex lens (part # L1593) from www.surplusshed.com:
In my setup I use Delta 20 (I took the lens only, it has f=90mm, dia:3") for reducing the image from LCD panel (15") to the size = 5". From that I use second lens (Plano convex lens with f=31,8mm, dia:11,4mm) to projected image to the screen (70" image size) with projector distance =16 ft. If I want smaller or bigger
image size, I just move Delta 20 forward or backward, also if I change projector distance, just move Plano convex lens to refocus.
I think (in theory) using 2 type of convex lens, short focal length for reducing LCD image and long focal length for projecting the image, will solve our problem with big LCD panel (14" up).
Hopely it will work.
fender4,
I did some experiment using Delta 20 Proj. lens (part # L1813) and Plano convex lens (part # L1593) from www.surplusshed.com:
In my setup I use Delta 20 (I took the lens only, it has f=90mm, dia:3") for reducing the image from LCD panel (15") to the size = 5". From that I use second lens (Plano convex lens with f=31,8mm, dia:11,4mm) to projected image to the screen (70" image size) with projector distance =16 ft. If I want smaller or bigger
image size, I just move Delta 20 forward or backward, also if I change projector distance, just move Plano convex lens to refocus.
I think (in theory) using 2 type of convex lens, short focal length for reducing LCD image and long focal length for projecting the image, will solve our problem with big LCD panel (14" up).
Hopely it will work.
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