Been eyeballing those sweet new high definition projectors? So have we. We're not going to feel guilty for it either, we know what we like. But if your wallet is a little light from your last Engadget inspired shopping session you might dig our how-to latest project. In Today's how-to, we'll start taking a look at building your own HD projector... from an LCD Monitor. This isn't one to be missed.
Building your own projector isn't a new idea. Disassemble a desktop LCD display, put a really, really bright light behind it and add some optics and voila! you've got a projector. The real question: is it worth it? Since you might be a little leery of dropping several hundred dollars on parts and gutting a nice display because people you don't know on an online forum said so, we're going to do it for you.
If you're hell-bent on doing all the research yourself, there are couple of places to check out.
Lumenlab recently made access to their forums free. Alternatively,
The DIYaudio forum users have some interesting ideas.
Lumenlab has put together a nice document
describing the details. We'll give you our short version here. The design is really quite simple. The light source is reflected towards the LCD. A Fresnel lens behind the LCD straightens the light so the maximum amount will pass through the polarized LCD. Another Fresnel focuses the light towards the projection lens.
The LCD is key to the project. The latest crop of LCDs is cheaper and better than ever. Notably, the contrast ratio has been increasing. It's important to choose a display that can be disassembled easily and won't have any inconvenient electronics in the way. Size does matter. LCD size will affect the lenses required and obviously the size of the completed enclosure. For our build, we chose the Samsung 940MW-SV Silver 19-inch 8ms Wide-screen LCD Monitor with built in TV Tuner. This beauty has a contrast ratio of 700:1 and a .294mm pixel pitch. The 16:10 screen has a 1440x900 native resolution, so it will display 720p natively. The built in scaler supports 1080 input as well.
We have to give props to the guys that are using the WXGA screen that's usually only found in laptops to achieve native 1080 resolution. There was enough interest for these that they actually had a custom controller built to support it.
More importantly, our LCD accepts almost any input. It sports DVI (With HDCP support), VGA, Component, S-Video input and even coax for the built-in TV tuner. We should be able to hook up just about any HD gear we want to this display. We run standard definition video through
our video scaler, but there's just not a good way to push a HD signal into the PC from an external tuner like our HD Tivo.
To maximize the light aimed at the screen, we'll add a reflector just behind the bulb. Some use Ikea napkin holders, but we opted for this reflector from Lumenlab. It's coated with a dichroic material that reflects visible light, but allows infrared heat to pass through.
The light source is a 400 Watt Metal Halide bulb. You can score these at the hardware store, but for the best color we want one that puts out light that's a similar to daylight as possible. That means a bulb with a color temperature of 6500 Kelvin (and hopefully an even spectral output).
The Mogul base of our MH bulb is quite a bit bigger than the average light bulb.
To ignite a Metal Halide bulb, some interesting voltages are needed. To produce them we'll need a ballast. These things come in a few flavors. The coil type are cheap, but produce a humming noise that might interfere with your viewing pleasure. Electronic ballasts are preferred because they'll protect the bulb better and don't produce annoying noise. Our 400 Watt MH electronic ballast cost $100+shipping from
HID hut. (They shipped it five minutes after we ordered!) We didn't expect it, but our ballast came with a ceramic Mogul base.
Back to our diagram we see that the LCD is sandwiched between a pair of Fresnel lenses. The lenses need to be at least the size of the LCD, if not bigger. The only source we could find with big enough Fresnel lenses is
Lumenlab. The Projection lens needs to be matched to the Fresnel lens on the same side of the LCD.
Since we required their large lenses anyway, we ordered a set of matched Pro lenses. The 'Pro' lens kit includes both Fresnel lenses and the projection lens.
Now that you've got the general idea of what we're doing, it's a good time to start crunching numbers to get a rough idea of what we're looking at. Lumenlab has a couple of calculators built just for figuring things out.
Focalcalc runs under windows. Remember that if you're entering the width of the LCD diagonally, then the screen width is a diagonal as well. If you prefer other OSs, there's a
php version that runs under most web browsers.
Lumenlab took about a week to ship out their backorder, once they did, our stuff got here in record time. The star of the order was this 'pro' lens. It costs about four times as much as its little brother, but it's the way to go if you're using a large LCD like we are.
We compared the picture quality from the HDMI and component outputs from our HR10-250. There was simply no question that the digital signal produced a much cleaner picture. Unsurprisingly, 720p output from the TiVo produced the most pleasing results.
We picked up a pair of new cables to get our video signals to the new photon gun. A 25 foot HDMI to DVI-D cable for our TiVo and a new 25 foot SVGA cable for the HTPC. No, the HDMI-DVI cable wasn't that expensive.
Before we add up all our parts, keep in mind that this is an Engadget build. There are plenty of ways to save money on this project, but we're feeling sassy. (And we're hoping to build something worthy of replacing a venerable Sony VPH-1272Q CRT projector.)
Let's recap all the parts we bought so far:
- Samsung 940MW-SV $330 from NewEgg (We spotted them at Sam's Club too)
- Pro Lens Kit (2x Fresnels and projection lens) $199 from Lumenlab
- Pro Reflector $15 from Lumenlab
- Ceramic Mogul Base $10 from Lumenlab (We scored an extra with our ballast)
- 400Watt 6500K Metal Halide bulb - $50 from Lumenlab
- 400Watt MH Electronic Ballast $99 from HID Hut
- 25 foot HDMI to DVI cable $37 from Monoprice [For our HR10-250 HD Tivo]
- 25 foot VGA cable $8 from Monoprice [For our HTPC]
Total parts cost far: $748
(This thing better work...)Left to buy: Enclosure, cooling fan and a few finishing touches.
Given the cost, why build your own? Replacement lamps for commercial projectors cost around $300 each and only last a few thousand hours at most. The lamp in our projector should last about 10,000 hours and costs $50 to replace. You can build your own projector for far less than we're spending. LCDs with bad backlights are cheap, and the lenses needed for the smaller LCDs are only $60 for a matched set. You can scrounge them up from surplus shops, but you'll spend some time hunting them down and getting things right.
We've geeked out, ordered a load of parts and scared our editors with the hardware tab. Next time we'll gut our sweet new LCD and give you all the details on doing it yourself. Then we'll move on to designing, testing and building our enclosure. When it's all done, we'll give it a thorough review.
posted Oct 17th 2006 4:05PM
the blotch and DIY_GUY are right...CRT's get much better res and contrast ratio I HATE everyone thinking LCD's are the best computer gaming display. On my gaming rig its CRT or nothing. BTW...blotch plz tell how you use the crt in this
I have a xbox 360 and a vga cable for it, will the vga cable work with the projector for xbox 360 if not... what do I have to do??
And also, how much in total did this cost to build?
Or for those too lazy to build their own projector, Lumenlab have a premade projector in the works which uses a $30 bulb, comes close to hdtv too I think! :-)
http://www.lumenlab.com/pm_projector.php
comes close to hdtv? you're not going anywhere near hdtv with that VGA plug on the side.
umm...those VGA plugs support hi-def inputs - I run a monitor at 1280x1024 through one, and could go higher if I had a better monitor!
How come engadget didn't go with a 17" lcd? Wouldn't it have been cheaper? Besides, 17" lcds usually have a native resolution of 1280x1024, more than enough to display 720p natively.
what an idiot ... you can do 1080p via VGA ... in fact you do it constantly 1280x1024 = hidef and 1920x1080 (some laptops) can all be done via VGA... learn what your talking about before you say something stupid.... again
BTW in these projectors you can do up to 1080p but is more expensive because you have to use a laptop lcd 15.4" and a controller board, but even with that it at tops custs 1800$ to build a 1080p projector, and compared to a retail one... the price is a frigging penny lol ya ya ... its lots less lumens than commercial but who cares its dirt cheap in comparison and media rooms are supposed to be dark lol ( though lumenlabs posters are fooling around with some crazy 1000w bulbs lol )
BTW i dont get why people go with the most expensive lcd...
NORWOOD 15.4" it does 720p and it has no ffc issues and it costs a wopping 75$ ... :) i think walmart sells it, search lumenlabs for norwood and you'll see people tlak about it it works great, its small so the projector stays relatively small and it does hidef 720p :)
Looks pretty sweet so far. I built an SD projector a bit over a year ago for only $200. It's pretty sweet for the cost, but the contrast leaves something to be desired. I'm looking to upgrade to an HD one now though.
For what this project is going to run you, you're better off picking up an Optoma HD70. It's only a grand and does 720p with a decent set of inputs. It's going to be a smaller machine and come with a warranty.
But if you like a good project and love building things yourself, this will be a lot of fun to mess around with.
Come on Engadget! using a 19" screen is so....yesterday.
http://www.engadget.com/2006/10/17/sanyo-epson-announce-7-1-inch-1080p-lcd-by-far-the-worlds-smal/
i was thinking the same thing before!
you could get a nice small box put together around one of those.
Wow this is crazy. I have all of those parts except the monitor sitting in my room right now waiting to be put together. I am planning on using a 17" monitor, but the problem with that is if you are not using a pc to send the image to the projector you have to use a convertor and from the quality I have seen they do not work very well. I just got hold of a Viewsonic N5 that converts composite, s-video and rf to vga, and it seems ok. I think I'm going to get a standalone component to vga adapter for high-def stuff. Anyways good to see somebody else is building one and I look forward to the rest of your guide.
Now if we just hook them up with the new Sanyo-Epson 7" 1080p screen then we could shrink the size quite a bit and have full HD support :D
Andy...
But how much does the bulb in the Optoma cost to replace and how long does it last?
It should be noted that the contrast ratio on these DIY LCD projectors blows, blows hard. It isn't so noticable on a small display in a lighted room, but projected in a dark room, it's bad. I'm all for the DIY spirit, but when the commerical option is much better, for little extra money, it's hard to justify the time it takes to build a kludge like this.
Funny, I have no problem with my DIY PJ in regards to contrast or brightness. Perhaps you've just run into people who don't know how to do it or what to use?
what i wanted some pictures of the thing built or a video of the mofo working
i was well getting into that
A for effort but this is going to be a large eyesore and I doubt it ends up being very bright. I understand doing this for the sheer geekieness but your friends are going to laugh at the giant projector cludge sitting in the middle of your room that you dropped $700 bones on. Also, lighting is a serious issue and I bet it ends up being very inhomogeneously lit without a lot of effort.
Prove me wrong engadget!
Try using that new 7" 1080p LCD Screen from, what was it ... Sanyo. That would make a good one. I myself have built a projector this way, and i have to say i couldnt be happier. The only better alternative would be to pick up an old school CRT Projector capable of 1080p for a couple hundred bucks.
Does it come in black ???
I have seen this sort of thing before only that done with an overhead projector and with an old 17" lcd which has broken backlighting. What you then basically do is stick the actual "lcd" bit on top of the OHP leaving some room for ventilation, I saw it done with some wood supports on the sides. The separation allows room for air ciruclation where you should install a regular pc fan of any sort. The tricky bit is managing to bring appart the lcd leaving all the connectors and buttons intact so that you can still plug it to your pc. The image quality and contrast is superb and it can be made for under $300!!!
umm... is that a USB linksys network adapter pluged into that DirecTivo HR10-250 ??
*ponders what ver. is that box running*
Why not just buy something like this? It's much cheaper. The link is even in CDN.
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=Projectors&product=2510264
I'd put it up against my cheapo Infocus X1 any day. There's no way that a DIY project is going to have good linearity across the entire picture for focus, and brightness, and it will have a poor contrast ratio. I've had mine for 3 or 4 years now and still have lots of time left on the first bulb. By the time the bulb goes, I'll be looking for a new one at twice the resolution.
It really depends on how you're going to use it. For example, we (me and the wife) use it to watch TV all day, which would really put a dent in a regular projector's life (say 2000-3000 hrs on average), whereas the bulb I use has a lifespan of 20,000 hrs.
If I just use it 6 hrs a day, that's 500 days (just over a year and a half) and I get to spend $200-400 on a bulb if I was using a commercial PJ. 6 hrs a day with my DIY puts me at 3,300 days (or 9 years), and then I spend $30 to replace my bulb. And it's also much easier for me to upgrade because then all I buy is a new panel.
Plus, I built it. That's a major wow factor for most anyone who comes by the house... and if you're good, you can make it look good, too.
hey yous guys with the "why not just buy these things"... 640x480 and 800x600 are NOT HD. show me one with 720p or 1080i.
Ok here's a couple ideas to throw out there:
Aren't video ipods equipped with a qvga screen? That might make a nice small projector, assuming you can find a screen.
What about leds for lighting? Leds are cheap, run cool, last long, and use very little power.
Hey! Just visited the Lumenlab website and the price of the Pro lens kit is $249.99 compared to the $199 that you have it listed for. Did they just jack up the price recently or what?
If one of the driving issues is replacement cost of lamps. Then why not hack your current projector to work with alternative light source, perhaps something more efficient and longer lasting?
Besides 500 to 1000 watts lamps, sounds more like you're talking about building a space heater than a projector.
Have you factored in energy cost to power the unit and cool the room?
Sounds more like the makings of a monstrosity than a geek toy.
1000 Watts! thats nothing! I've helped set up 2 sets of three 2kw lights.
What about a bulb from a SAD lightbox? These are 10000 lumens and are daylight simulation bulbs.
I have this 10 year old system: a translucent LCD screen to put on top of an ordinary old-style overhead projector. There's a fresnel lens, a big lamp, a top lens and a mirror, all in one box.
You are reinventing the wheel!!!
Looks to be about a grand. You can buy a 720P Optoma for $999. It is smaller too.
lol right now I'm making a 100" 1080p projector for really cheap to use with my Mythbox (a computer that uses MythTV, a Linux DVR program that is much better than Tivo and has more feature and is completely free, to record TV) that I'm building, a lot cheaper than this. The projector itself is slightly under $100, 16:9, has DVI input, and is a CRT, which is much better quality than LCDs, and usually have a contrast ratio of about 70000:1. Then, I'm getting a $86.55 100" projector screen to use with it. Also, I'm getting a $60 140 watt (it's in a small room, my bedroom, so it probably has good acoustics) Dolby Pro Logic II five-speaker + subwoofer surround system. The Nvidia DVI output card I'm getting (it supports resolutions much higher than 1080p) is about $20 and the 10 ft. DVI cable is about $10. All together, its about $270. Plus, I'm using a firewire card to capture 1080i HD from my HD cable box, which is a little over $10 and uses extremely low CPU. MythTV can be set to automatically deinterlace captured video, so I'll get 1080p HD on my projector. The Mythbox is very cheap, because I'm using a computer I already own, and it has a 2.26 GHz Celeron D CPU. All I'm adding to it is a 250 GB hard drive ($54.90), a new motherboard (about $30, my old one shortcircuited), and the firewire card I mentioned earlier. Once I have the projector set up I'll put a video of it on Youtube and post the link here, but, most likely, the Mythbox won't be set up at the time, so I'll just make it a video of me playing HALO on my laptop (plugged into the VGA port of the projector) with a Wii remote, and maybe I'll post another video of part of a DVD on the projector, although it will only be 480p (480i deinterlaced).
yo The Blotch what are the part for the projector and were can you get them
The Blotch is sadly mistaken or doesn't know what he's talking about or just want's to spread lies. he say's CRT is much better quality than LCD. Is he crazy? When I read this I had to stop reading right away! I hate being disieved.
Just built one using a $20 OHP(3000 Lumen) and a 17" $20 LCD monitor both purchased from e-bay. Am really happy with how it turned out. Could have done better with a 4000 lumen OHP. $5 mini-fan from Wal-Mart keeps the LCD cool. Have watched a ton of movies on it so far!.
Hi Jude,
Would you please be able to describe how you built the projector setup with OHP & LCD, to run video games or connect with PC for presentation / movies ? I'm a newbie in this & am getting misguided enough to get disapponted & to turn towards commercial projectors :-(
Rick, sorry to disapoint you, but CRT blows away LCD quality. Just because LCD is a newer technology, LCD panels are poor in contrast, but are nice to have and ALOT more expensive then CRT because it is so thin. CRT is an older technology, but it has contrast ratios that can be as high as 150000:1, and resolutions of 2048x1488, which is much better then 1080P. It is amazing how people asume that when they by their LCD TV's, they are paying for quality. They are not. What they are paying for is the popularity of them because of the extremely thin size. Type in CRT vs. LCD on google and tell me what you get.........