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A Practical Guide to DIY LCD Projectors

CmdrTaco posted more than 9 years ago | from the because-you-can dept.

Displays 217

Compu486 writes " has a new article entitled "A practical guide to DIY Home Projection". The guide covers the basic theory behind projection and provides a step by step guide for a "Practical" DIY LCD Projector. Although this topic has been covered before, the perspective they offer is refreshing."

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Thats nothing (5, Funny)

Anonymous Coward | more than 9 years ago | (#13052902)

In my day, we made our own movies using a light bulb and creative hand poses casting animal shaped shadows...

Re:Thats nothing (1, Funny)

Anonymous Coward | more than 9 years ago | (#13052966)

You had a light bulb?! LUXURY!

In *my* day, we had to wait til lightning struck a tree and set it on fire to get any sort of light.

And when our branches burnt out, we had to go out of our caves to look for more sources of fire again.

Re:Thats nothing (0)

Anonymous Coward | more than 9 years ago | (#13052983)

Is that the same technology that allows one to make a ghost ship using two Q-tips, a candle and a squirrel?

Re:Thats nothing (0)

Anonymous Coward | more than 9 years ago | (#13053300)

I wouldn't call what you're doing with your hand "casting animal shapes".


Re:Thats nothing (0)

Anonymous Coward | more than 9 years ago | (#13053404)

I wouldn't call what you're doing with your hand "casting animal shapes"
Sure it is- It is casting (a very small) American Zipper Snake as it enters a small hand shaped cave repeatadly....

I wish.. (0)

Anonymous Coward | more than 9 years ago | (#13052905)

I wish they could use real images instead of obvious fake ones []

Argh! Enough already (-1, Flamebait)

stefanb (21140) | more than 9 years ago | (#13052911)

What is this, lame projects day? First an ugly, loud, useless "rack" [] , then a crappy, ugly shelf [] , now this?

Re:Argh! Enough already (3, Funny)

nitio (825314) | more than 9 years ago | (#13053006)

well... you could connect your notebook that is on the crappy ugly shelf to the ugly loud useless rack and then project all your porn in your new projector.

Re:Argh! Enough already (1)

Jakhel (808204) | more than 9 years ago | (#13053354)

Then you can roast marshmallows on the insuing bon fire that was once your house.

Finally (3, Funny)

mfloy (899187) | more than 9 years ago | (#13052915)

Now I can finally watch my reality TV shows on a bigger screen. This is truely a fantastic day.

The perspective they offer is refreshing (0)

Anonymous Coward | more than 9 years ago | (#13052924)

I've found the perspective must be refreshing at 25ms or less to get adequate results.

resolution (1)

ohyedoggies (859303) | more than 9 years ago | (#13052927)

what can the resolution potentially be?

I'd rather (4, Informative)

Evangelion (2145) | more than 9 years ago | (#13052934)

Go with LumenLab [] 's plan, if I was to do this at all.

And they have real pictures too, instead of faked images on thier site.

Re:I'd rather (0, Flamebait)

SpooForBrains (771537) | more than 9 years ago | (#13053127)

Why do people wait for my modpoints to run out before they post crap like this?

Re:I'd rather (0)

Anonymous Coward | more than 9 years ago | (#13053416)

Can you elaborate? Is lumenlab crap, or is their plan crap, or what? What would you recommend?

Re:I'd rather (1)

SpooForBrains (771537) | more than 9 years ago | (#13053749)

It's a blatant sales pitch. The entire page is just a "whee, look what you can do with our wonderful document, if you just pay us $20! Woo!"

Re:I'd rather (1)

towaz (445789) | more than 9 years ago | (#13053303)

I built my projector from lumenlabs a few months ago, have a nice 3 meter screen at 16ms response for playing counterstrike and films.

Cost me about £300 ( benq 15" lcd was most expensive bit) to build, Its so bright and sharp I put my friends £3000 projector to shame.

Took it outside during a bbq at night and projected on the back of my house with no problems either.. roughly 7 diag. meter screen from two white sheets :)

Re:I'd rather (1)

passthecrackpipe (598773) | more than 9 years ago | (#13053357)

spamming on /.? thats brave....

Re:I'd rather (1)

fishdan (569872) | more than 9 years ago | (#13053673)

If there plan was FREE maybe I'd go with it, but charging $20.00 for PLANS to build something is a little too much like those ads in the back of comic books for me.

Not a good field for DIY (4, Insightful)

Arthur B. (806360) | more than 9 years ago | (#13052936)

I don't really get why one would want DIY here... Having a video-projector, say for home-cinema sake or gaming is mostly about quality of the picture. Apart from the sake of learning I'd rather buy one. Oh, and not a LCD one, at least a DSP. Although laser projection tech has been around for some time now, I'm really surprised that it's not used. Although sounds like a feasible DIY project.

Re:Not a good field for DIY (0)

Anonymous Coward | more than 9 years ago | (#13053150)

A "DSP" projector has some disadvantages compared to an LCD; it depends on what you're using it for. Home theater users should stick with the DLP.

"Laser projector?" Dude, unless you're planning on doing a production of "Laser Metallica" at home, you might want to hold off on buying one. Did you hear about that from

Re:Not a good field for DIY (1)

Arthur B. (806360) | more than 9 years ago | (#13053270)

Meant DLP not DSP... Laser projection is, in its principle much simpler than dlp or lcd. dlp needs millions of tiny mirrors, whereas laser only need a few. You have to achieve two things 1) dim the intensity according to the color (can be achieved by going through a polarized material through a variable angle, using a controlled mirror) 2) scanning the screen, rotation of small reflective device... imagine a mirror spiral on a cylinder

Re:Not a good field for DIY (1)

kris_lang (466170) | more than 9 years ago | (#13053743)

ah yes, but getting a good quality blue laser to use for the projection will not only cost you a lot but also require quite a bit more cooling than you might think...

Re:Not a good field for DIY (1)

Steve525 (236741) | more than 9 years ago | (#13053178)

I don't really get why one would want DIY here...

Cost savings, and the fun of doing it, I guess.

I've never seen one of these homebrew things in operation, but I share your doubts about the picture quality. Every overhead projector I've ever used has had pretty crappy geometry, and uneven illumination. They're also noisy and run pretty hot. (I know that's what the enclosure is for, but simultaneously getting rid of heat and noise is tricky).

BTW, I think you mean DLP, no DSP.

Re:Not a good field for DIY (0)

Anonymous Coward | more than 9 years ago | (#13053217)

Well, projectors were first used for presentations. Quality is a tad less important there.

Re:Not a good field for DIY (1)

evilviper (135110) | more than 9 years ago | (#13053358)

I don't really get why one would want DIY here...

No, what you don't understand is why someone would want an LCD projector. Whether it's homebrew or commercial, the picture quality will be basically the same. In fact, because of the larger form-factor of most home-brew projectors, you have the possibility of using a much, much higher-res LCD panel for your projector.

Re:Not a good field for DIY (2, Informative)

MythMoth (73648) | more than 9 years ago | (#13053425)

Although laser projection tech has been around for some time now, I'm really surprised that it's not used.

Last time I looked into it green lasers were prohibitively expensive and blue lasers were completely untenably expensive.

Re:Not a good field for DIY (3, Interesting)

kris_lang (466170) | more than 9 years ago | (#13053757)

Yup, and blue lasers need quite a bit of cooling and you need a lot of power for them.

LaserPower (now defunct) used to make a laser projection display with microlasers. And there's a company that projects displays directly onto the retina (microvision) with microlaser and diode-laser sources. (i don't know that I'd want to point even a low power laser device INTO my eye...

and then there's the problem with the lack of persistence for viewing the images.

Nice, but... (1, Interesting)

suitepotato (863945) | more than 9 years ago | (#13052938)

Although this topic has been covered before, the perspective they offer is refreshing.

Why? Does it give me a free beer with it?

Cursory overview leaves me unimpressed. It seems like a rehash of prior projects but using simpler and less expensive parts. Result: a projector that has less lifespan than a low-end projector for a bit more money and no warranty.

I'd rather wait a little while longer and wait till the technology matures a bit more. If I come into some money I can spend freely on a projector, I'll buy one that can do at least 1024x768 PC input and make sure to buy spare projector parts with it.

Re:Nice, but... (1)

fshalor (133678) | more than 9 years ago | (#13053048)

I think this was mostly just a protest to the delming going on in advertized specs by the main players in this field. (Shame on you you big manufacuteres you! You should know better!)

Anyways, it'll get people thinking a little, and let them get a bit more edumacated (W.) about what these things can actually do.

I'll stick to my Sharp for work. Love the thing. It nearly burns the ceiling tiles when it kicks off, but looks ultra sweet.

DIY Digital Projection (5, Funny)

LegendOfLink (574790) | more than 9 years ago | (#13052940)

Nah, my idea is better. Re-wire a retina scanner to output a DVD stream, and then you've got the BIGGEST picture of them all.

Although I did see Matrix 3 in the IMAX, and it was a little scary to see Morpheus's face. I mean, the dude had like 2-foot pores!

Re:DIY Digital Projection (1)

dreadknought (324674) | more than 9 years ago | (#13053525)

So what exactly is a "Digital Video Disc stream" and how do you output it onto your retina?

In Soviet Russia (-1)

Anonymous Coward | more than 9 years ago | (#13052955)

The Screen projects you!

Faster & about the same price (1)

jurt1235 (834677) | more than 9 years ago | (#13053014)

1. Take an old overhead projector, gives you the light & the focus part at once.
2. Strip LCD screen (takes about 20 minutes if you do it carefully and want to be able to reassemble it later).
3. Put the lcd without backlight on the projector, and you are done.

Yes, it is carppy mod day!

Re:Faster & about the same price (1)

TripMaster Monkey (862126) | more than 9 years ago | (#13053156)

Put the lcd without backlight on the projector, and you are done.

Just remember to put a spacer in between the LCD and the projecor, with a fan pushing air between the two, or you will scorch your LCD panel.

Re:Faster & about the same price (1)

jurt1235 (834677) | more than 9 years ago | (#13053708)

Hum, there is a good fan already cooling the overhead projector by itself. It needs to else the standard overhead sheet (the ones you write on during the presentation) get to hot to use in a decent way. The panel is thicker ofcourse, and might isolate the glass projector plate too much.

One way to find out for sure: Try it (-:

Re:Faster & about the same price (0, Offtopic)

sprag (38460) | more than 9 years ago | (#13053327)

"carppy mod day"? I think carp would look cooler with an extra tail. And maybe a goatee.

Re:Faster & about the same price (1)

jurt1235 (834677) | more than 9 years ago | (#13053681)

So carppy that I write crappy wrong, and just refuse to use the preview option

Dear Slashot (0, Troll)

Anonymous Coward | more than 9 years ago | (#13053038)

Dear Slashdot;

I'm sorry I haven't wrote earlier, or made an account for that matter. I've been looking at you from afar for all these years, reading your posts, laughing at the good times, cringing at the bad. We've been through the dot-com, the dot-bomb, together.

Sometimes our relationship seems to go in circles, but you come back and make it better. Today though, I'm leaving you. Oh sure, maybe I'll visit, but it won't be the same. I just can't forgive you for this; a shelf, a case mod, and another LCD DIY. It's been nice, take care.

Perfect timing! (1)

FrontalLobe (897758) | more than 9 years ago | (#13053045)

Wow, this is great. We're looking at renting a projector for my brothers wedding coming up, but the cost is pretty high. We have access to a screen, and I'm pretty sure an overhead. If I can get my hands on a cheap LCD projector, that'll cut our costs by at least 400%. Wouldnt bother with all the casing and such. Plus I get to keep the thing =D

Although I'm not sure I'd want to use something so kludgy for a once in a lifetime event...

Re:Perfect timing! (5, Funny)

Living WTF (838448) | more than 9 years ago | (#13053090)

> that'll cut our costs by at least 400%

Your calculator was a DIY project too, wasn't it?

Re:Perfect timing! (1)

FrontalLobe (897758) | more than 9 years ago | (#13053122)

Nope... that would be my brain... dang early morning slashdot posting...

DIY day? (2, Interesting)

Lxy (80823) | more than 9 years ago | (#13053064)

Is today's Slashdot being brought to us by the DIY network or something?

Build a rack!
Build a shelf!
Build an LCD!

I admire the geek who homebrews hardware, but this is getting rediculous.

Re:DIY day? (2, Interesting)

nizcolas (597301) | more than 9 years ago | (#13053192)

Except in the article you don't build the lcd, and the housing is optional.

However I must admit that I'm more inclined to do this than the version where you tear the lcd apart. I talked to our hardware guy at work and asked him if he'd feel comfortable disassembling and lcd for a project like this. His response was something like, "as long as it wasn't mine."

Re:DIY day? (1)

3.14159265 (644043) | more than 9 years ago | (#13053212)

Rediculous is absolutely ridiculous...!

Re:DIY day? (1)

V_Pundit (794571) | more than 9 years ago | (#13053400)

Hey! I was about to try posting a story about how to build your own rudimentary keyboard. It's completely configurable to your own personal tastes and can be done with nothing more than a few small wires, a bunch of springs and some small stones. Talk about portable, whenever you want to take it places you can just sweep it all into a bag and set it up again when you get where you're going.

Paint your own screen (5, Interesting)

Drog (114101) | more than 9 years ago | (#13053101)

I've been reading up on this recently as I'm planning to build myself a home theatre in my basement this summer. Rather than buying or building a screen, I'm simply going to paint it onto my wall using a new type of paint called "Screen Goo" [] (I read a review of it here [] ). Supposedly, it gives excellent results.

As for the projector, I don't want to build this thing myself, I'm willing to spend the bucks. So I'll likely go for the Panasonic PT-AE700U, which I've seen reviewed here [] .

So that leaves me wondering what sort of PC or hi-def receiver to buy to power this thing, so that I can use cable, satellite, game console, DVD, PVR and the PC.

Any advice would be most appreciated.

Re:Paint your own screen (1)

xENoLocO (773565) | more than 9 years ago | (#13053134)

Not to nitpick... but why the hell is there a golfer on the top right of their website?

Heh heh (1)

Drog (114101) | more than 9 years ago | (#13053174)

I just refreshed it a few times. It's randomly either a golfer or NFL players. The idea being, I guess, that you're watching sports on your home theatre system.

Re:Paint your own screen (1)

calibanDNS (32250) | more than 9 years ago | (#13053298)

Off topic, and not quite what you asked for, but if you haven't settled on a remote control for your setup yet, I just picked up Logitech's Harmony 880 [] and it is fantastic. I know I sound like a commercial (and no, I'm not affiliated with Logitech), but the Harmony is really the best thing I've found on the market for controlling a high-end system. There are LCD-only remotes that allow you to customize the button layout more than the Harmony, but I found that having to hunt for a button everytime I needed to press it is not as easy as finding most of the buttons by feel. The price is high (US $250), but other model Harmony remotes are cheaper if your budget is tight. The list of devices that it can control is impressive (create a test login at Logitech's Harmony site to see if the components you have/are getting are already supported) and their customer service has been excellent so far. Be sure to check out the forums at Remote Central [] for discussion on the Harmony and other high-end remotes. And trust me, you won't be truly happy with your system until you can easily control it the way that you want.

Re:Paint your own screen (4, Informative)

The-Bus (138060) | more than 9 years ago | (#13053306)

Well, you will probably want to invest in a good DVD player. The decoding between players can have a big difference on image quality. I am not a videophile, but in my experience it's not so much the quality during slow, colorful scenes, but during very rapid sequences where you might see issues with playback. The Home Theater Forum [] is always a great start (they have a very nice moderated DIY section), and I am looking into possibly getting an Oppo Digital DVD [] which has been extremely well rated. As a plus, places like HK Flix [] sell it with updated firmware (so you can switch regions easily on the fly), although I've seen it for $50 less on Froogle [] .

As far as receivers, I can give you my analysis and feedback as a regular consumer (I wouldn't even call myself a "prosumer") of home theatre electronics. You definitely would do well in investing in a good receiver with as many inputs as possible, and don't get them from Circuit City / Best Buy / Fry's as they are usually $100 more than what you can find online. In reality, you will probably not need more than 3 or 4 component inputs (DVD + HDTV + Console + Other). Depending on the # of inputs on your TV/projector, this should put you in the $300-$500 range for receivers. Look for wattage ratings and buy from a well-known company (say, Harman-Kardon, Denon, Onkyo, Sony, Yamaha).

Once everything is set up, get a calibration DVD like Digital Video Essentials [] or Avia [] to tweak your settings. It can make a noticeable difference.

You don't need Monster Cables. If you have a friend at a store who can get you the discount (retailer markup is at least 100%), then they're fine. But you don't need to spend $300 on cables. Spend that money on better equipment.

Just do your research. It's possible that over the next few months older models will be discontinued and be heavily discounted. That can always save you some cash.

Thanks! (1)

Drog (114101) | more than 9 years ago | (#13053398)

Thanks for the excellent advice.

Re:Paint your own screen (1)

Tamugin (851088) | more than 9 years ago | (#13053417)

I built my screen, and in researching how to do it I looked at Screen Goo. Nice product, however you'll have a hell of a time getting a nice even and run-free coating on your substrate. If you thin it and use a nice sprayer you should be ok.

I however, opted for the even cheaper method of Plas-Tex. I believe it is made by Parkland and is initially indended as wall covering in wet areas; public restrooms and such. The nice thing is that it has a gain of almost 1.0 and doesn't hotspot at all. I picked up a 4'x8' sheet at the local hardware store for $13. I built a wood frame and secured the plas-tex to it like a painting canvas. Some black material for masking and I have a great screen that is rigid and flat. [] It looks really great with my Marquee 8501 throwing light onto it.

Re:Paint your own screen (1)

Mr. Flibble (12943) | more than 9 years ago | (#13053661)

You may want to read this for your screen first: .php?s=&threadid=224307 []

Less expensive than buying the screen paint, and from the sounds of it, both more effective and a nicer looking finished solution on your wall.

Call me when (5, Insightful)

amcdiarmid (856796) | more than 9 years ago | (#13053110)

My wife will accept one in the living room.

Otherwise this is just another "Overhead projectors with LCD panels make big ugly projectors that you cannot use anywhere but a darkened room" story.

Hmmmm (5, Funny)

Phurd Phlegm (241627) | more than 9 years ago | (#13053111)

I read one page--the one on "Theroy." I find it distracting when someone doesn't bother with even elementary proofreading. If the content is interesting enough, I can overlook it, but this didn't seem all that novel. Just so there'd be some discussion, I made a quick list of the first errors that sprang out at me in the "Theroy" page [] . Doesn't everyone know some pedantic jerk that will edit their stuff for them?

  1. principals : principles
  2. cheep : cheap
  3. cellulous : celluloid?
  4. threw : through
  5. LCD's : LCDs
  6. Simi-gloss : semi-gloss
  7. portal : portable
  8. Walmount : wall-mount
  9. theroy : theory
  10. togeather : together
  11. its : it's
  12. . : ?

    I anxiously await the first person to point out a spelling or usage error in my post--it's traditional.

Re:Hmmmm (0)

Anonymous Coward | more than 9 years ago | (#13053181)

theroy : theory

Re:Hmmmm (2, Funny)

I confirm I'm not a (720413) | more than 9 years ago | (#13053195)

I anxiously await the first person to point out a spelling or usage error in my post--it's traditional.

Dude! You misspelt "fuc... oh, forget it.


Re:Hmmmm (1)

timster (32400) | more than 9 years ago | (#13053235)

Well, I had a college professor tell me that the use of the dash should be carefully constrained, lest it lose its force through overuse. Twice in a short post would certainly be over her limits.

Also, isn't a jerk a person? So should it be "a pedantic jerk who"?

Re:Hmmmm (1)

hhghghghh (871641) | more than 9 years ago | (#13053250)

I anxiously await the first person to point out a spelling or usage error in my post--it's traditional.

Very well. The comma after "If the content is interesting enough" is superfluous. Happy now, punk?

Re:Hmmmm (0)

argStyopa (232550) | more than 9 years ago | (#13053302)

Theroy is correctly spelled THEORY.

(It's equally traditional to not RTFM)

Re:Hmmmm (1)

Noel Coward (16378) | more than 9 years ago | (#13053503)

> I read one page--the one on "Theroy."

Should at least be:
I read one page--the one on "Theroy".

spend the same on a widescreen CRT but sit closer (2, Insightful)

hilaryduff (894727) | more than 9 years ago | (#13053113)

a 1024x768 screen is going to look pretty damn pixelated blown up to 100" unless you sit quite a way back!

It's Not Worth It (3, Insightful)

dafz1 (604262) | more than 9 years ago | (#13053116)

The author of the article keeps saying it's better to DIY than spend $5K on a commercial model. However, you can get a decent projector for $800(or less if you buy a refurb non-current model). Plus, the picture quality is a lot better(supports 480i, 480p, 720p, and 1080i), and is in an appealing form factor.

The other question is how noisy is the overhead projector? Remembering back to elementary school, those things were pretty loud.

Re:It's Not Worth It (1)

Drog (114101) | more than 9 years ago | (#13053209)

Yeah, I agree. There's no way I'd want an ugly, noisy, low-res projector like that in my living room.

Re:It's Not Worth It (1)

og_sh0x (520297) | more than 9 years ago | (#13053221)

For $600 you can build a 1024x768 projector with DVI input and brightness equivalent to a 1500 lumen projector. The bulbs cost $40 to replace and last 18,000 hours. Parts are cheap and interchangable, should something go wrong (heat is the major issue.)

Your $800 refurb projector will be an 800x600 with no DVI support and $300 bulb replacements twice a year. Good luck repairing it cheaply if something else breaks.

Re:It's Not Worth It (1)

LetterJ (3524) | more than 9 years ago | (#13053505)

Many of the $300 bulbs are now rated for 4000 hours. Just how much are you watching in a day?

Re:It's Not Worth It (1)

og_sh0x (520297) | more than 9 years ago | (#13053622)

They're rated for 4000 hours often times in "economy" mode where you're watching a much dimmer screen. Also, the bulbs carry a 90 day warranty only. They can and will sometimes burn out after only a couple hundred hours of use, especially if the projector is often transported. I know at work I've seen a bulb implode after as little as 30 hours of use. It's a dirty little secret of the cheap, miniature projectors. Much like the dirty little secret of the cheap inkjet printers. It's practically a loss leader.

Re:It's Not Worth It (1)

Overzeetop (214511) | more than 9 years ago | (#13053711)

You're nuts right? Or you've never used an overhead projector. There's a reason they usually have a dedicated place for a replacement lamp - the lamps don't last long. I quote:

In a test done by GTE/Sylvania on 10 ENX lamps, the range of life was 34.3 hours to 76 hours. The average lamp life for this batch was 68.7 hours, higher than the published average of 65 hours. However, the lamp that lasted only 34.3 hours is not considered to be defective.

Okay, so those lamps will run you $6/ea in quantity. I'll give you $6/70 hours. That's $0.08/hr. More like $0.16/hr if you get a short one, that is still within spec. Modern projectors will get you 2000-4000 hours *to half brigtness*, not necessarily failure, for $300. At the worst case, that's $.15/hr, and the best case $0.075/hr. And the number of movies interrupted by a lamp change is 1/50th of that with an overhead.

Next, that 1500 lumen projector is going to put out about 300-400 from the last optic, if you're lucky, once you put an LCD panel on it.

Finally, even the OP admitted that the thing was LOUD due to fan noise. Many HT projectors - even the cheap ones, as so quiet that you can't hear them except in silent passages of the film (sub-35dB).

If you're watching mostly DVDs, or don't "need" HD resolution, the following NEW, 16:9 DLP with SCREEN could be had for $900 after rebate this month. From FatWallet, on the InFocus 4805 dedicated HT projector:

The deal is available at Circuit City until Monday July 4th.

The projector is $1099.99+ tax...

Use the new 10% off CC coupon code DJA3QLGADC

Total should be 989.99 +Tax

Circuit City qualify's for the $100 rebate as well as the 76" Wall Mount Screen from Infocus.

(Quick Edit: It looks like the screen mail in rebate is only valid until 7/2 - so if you want it you have to pull the trigger fast hehe)

Total with the rebate, screen and 10% off would be $889.99 + tax

These deals happen all the time.

I'd say your $600 is a waste of money, when you can just turn a couple extra tricks and get the real thing.

Re:It's Not Worth It (1)

jason718 (634659) | more than 9 years ago | (#13053229)

I agree - $1K will get you (from a well known warehouse store) a brand new fantastic DLP projector that is great for movies and gaming. They even throw in a 72" 16:9 screen as well.

Re:It's Not Worth It (1)

evilviper (135110) | more than 9 years ago | (#13053309)

Plus, the picture quality is a lot better(supports 480i, 480p, 720p, and 1080i), and is in an appealing form factor.

Point me to an $800 projector that can handle 1080i (1920x1080).

The other question is how noisy is the overhead projector?

It's easy to replace the fan.

Seconded! (2, Informative)

gilesjuk (604902) | more than 9 years ago | (#13053684)

Look at the cost of life of the bulbs in OHPs. Typically 50 hours and cost of about £30-50 here in the UK.

Bulb life in a projector is typically 2000 hours (4000 in mine) and cost about £250 for the bulb.

So using 2000 hours as an example:

Projector cost £599 will last 2000 hours so total cost for first 200 hours is £599.

Self made projector will cost about £200-300, for 2000 hours of use you'll need 40 bulbs at £30 a go which works out at £1200 for bulbs and £200-300 so grand total of £1400-1500 (for which you can get a good DLP).

You also end up with a big ugly box which you can't place anywhere easily, a projector with no analog inputs, no warranty, no adjustments to compensate for placement etc etc.

Just buy a projector, it'll be safer too, something you can leave for 30 minutes and know you aren't going to come back to a fire.

Interesting tidbit from the article (2, Informative)

Woogiemonger (628172) | more than 9 years ago | (#13053139)

When commenting on lenses, it says:

"Many lenses are coated to improve the optics of the lens. Products like Windex will severely damage these coatings resulting in pilling, fogging, or even etching of the actually glass. FYI, most CRT monitors are subject to the same conditions. Don't ever clean your CRT with Windex or similar products. Of course you would know this if you read the manual."

Didn't know that! :) It's nice to get immediately useful info from an article about something you don't have time for.

Re:Interesting tidbit from the article (1)

DocSavage64109 (799754) | more than 9 years ago | (#13053707)

Actually, your monitor's screen is quite easy to damage. It is much like the window tint on a car. (I discovered this after a kitten scratched my screen and I tried to buff the scratch out. I ended up having to peel plastic off the entire screen. After all that, my black levels sucked and I was probably getting irradiated at dangerous levels.)

Light passes through? (1)

igotmybfg (525391) | more than 9 years ago | (#13053166)

I've been reading and re-reading the article to found out how the LCD acts as an imagery medium. How does this work? When I think LCD, there is the side that faces you and has pretty pictures and whatnot, and there is the side that has a plastic casing on it. How/where does the light pass through?

Re:Light passes through? (1)

frieked (187664) | more than 9 years ago | (#13053201)

How about RTFA again.
He explains that he uses a proxima ovation lcd panel for this project which light can pass through
Here's a pic of it []

Re:Light passes through? (2, Informative)

Anonymous Coward | more than 9 years ago | (#13053222)

an LCD monitor actually has a backlight behind the LCD screen, so to get the picture, you actually cannibalize a monitor, and use the LCD screen itself with a bright light behind it, and Fresnel lenses to focus the image...check out [] for more info...

Re:Light passes through? (1)

og_sh0x (520297) | more than 9 years ago | (#13053282)

An LCD monitor itself is translucent. Behind it is a light source. It's encased in plastic to keep the light from escaping out the back. Remove the casing and shine a much brighter light source through the LCD. The rest is focusing and heat removal.

Re:Light passes through? (1)

thedak (833551) | more than 9 years ago | (#13053676)

The backlight of an LCD is a luminescent sheet behind the 'sheet that faces you and has pretty pictures' so, the light passes through that part. (okay, ibooks have a luminescent sheet, others may have another lighting mechanism I seem to remember a friend's compaq armada having lighting from the right and left sides of the screen basically shining across.... very irritating in low light as you could actually see the swath of light from the sides.. *shiver* [old old 700Mhz era armada, so relax those of you who like the armadas, I agree, very nice laptops, magnesium lid, sexy]).

So naturally as one would assume, the plastic/magnesium/titanium/whatever the heck your lid is made out of casing comes off, the luminescent screen in my case comes off (oh to hell with taking mine apart) and the LCD screen itself is used to pass light through.

Silly if your goal is to have a projector (1)

Raunch (191457) | more than 9 years ago | (#13053179)

Now, I do admit that its bigger brothers in the 5K price region have a little bit better resolution, and a little better refresh rates. But when comparing the bottom line here 0.2K verses 5K... it still blows my mind. The real benefit here is in the budget for our version of the DIY projector, we got a really nice screen out of it.

I bought mine on ebay for 600 dollars, and it has a remote control, will mount to the ceiling, and does NOT sound like a vacuum cleaner. Not to begruge anyone their project, but there is no good reason for anyone to ever build one of these things unless they are *really* strapped for cash, or they are bored and want to play (much better reason as far as i'm concerned).

Re:Silly if your goal is to have a projector (1)

evilviper (135110) | more than 9 years ago | (#13053247)

I bought mine on ebay for 600 dollars, and it has a remote control, will mount to the ceiling, and does NOT sound like a vacuum cleaner.

The noise can be easily fixed by replacing the fan.

The main issue that concerns me was addressed in the article. Commercial projectors tend to use very expensive bulbs, for no good reason. Your $600 projector may have a bulb that will need to be replaced several times a year, which costs $100+ each time...

Point me to a $600 projector that uses a $10 bulb... Haven't seen them yet.

Re:Silly if your goal is to have a projector (1)

Trifthen (40989) | more than 9 years ago | (#13053768)

What I don't get is why they never use the equivalent of the bulbs used in car headlights. They're bright enough to light up the entire road, last forever, embarrassingly inexpensive, and I could go on like this forever.

Build a proper enclosure based on a car headlight and reflective backing with some kind of focusing mechanism, and you'd get something smaller, quieter, using less voltage, and so on. I mean, sheesh.

DIY? (4, Insightful)

WhatAmIDoingHere (742870) | more than 9 years ago | (#13053194)

How is this a "do it yourself" project? You bought an overhead projector. You bought the LCD display that was made to go on overhead projectors. You bought a screen.

The only DIY here was "Make a box with a window in it" and that's not really a "Do it yourself LCD projector" now is it?

What a crock. (0, Troll)

millennial (830897) | more than 9 years ago | (#13053215)

Cost: $174
Cost of SCREEN to project onto: $110
Why would you not just hang a sheet on your wall?

Re:What a crock. (1)

SisyphusShrugged (728028) | more than 9 years ago | (#13053401)

He states specifically in the "guide" that projection screens increase the quality of the image significantly.

Dude, just... (1)

CaptainFork (865941) | more than 9 years ago | (#13053225)

...sit closer to your monitor!

Low light v. High light (2, Informative)

Raunch (191457) | more than 9 years ago | (#13053227)

I have to be honest, this screen is really worth it. It looks great in low light and no light situations and is very clear.

Projectors look really good in low light and no light situations, on a sheet or a wall, or on your little brother. The test of a screen is how it does in situations with higher amounts of ambiant light.

umm.. (0)

Anonymous Coward | more than 9 years ago | (#13053274)

why bother..

i recently plunked $1200CDN down on a old (circa 1994) "used" (4000 hours) sony CRT.

It will display 1080P.. which is more than enough..

i have a 120" screen in my basement now.. and it's VGA in as well.. (RGBHV).. my mythTV (necessary linux plug) and well.. it sure beats the crap outta any LCD/DLP solution i've seen lately for $5K+ (and that's professional not some hacked together POS)

LCD panels with overhead projector = HORRIBLE SCREEN DOOR..

so unless your a geek with cokebottle lenses in your glasses and everything is "kinda blurry" anyway and you need a 100" screen and LARGE FONTS to even see your 800x600 screen.. then don't bother.

OTOH.. go head and build one.. just means when i want to upgrade my CRT there'll be less people that want them. Go get your fresnel on..

(BTW.. has slashdot been taken over by the womens network? it's full of how-to articles.. UGH.)

Well, there is another DIY projector (1)

sixpacker (687012) | more than 9 years ago | (#13053291)

and it just costs around $600. Its max resolution is 1280x1024. According to what I've heard so far, it's very nice. Visit here(Korean site), 97818968 []

Strong light (1)

Doppleganger (66109) | more than 9 years ago | (#13053388)

"Light passing threw the film, and interacting with a shutter created the viewable content."

Beware of flying film, particularly when it's thrown by passing photons.

Geeks in fabric stores (1)

Woogiemonger (628172) | more than 9 years ago | (#13053422)

We will be using some felt that we acquired at the local fabric store. Now I will say this on the note of the fabric store types: Not Geeks! These are the types of people that never get out and experience the world. And their idea of creative or innovative thinking is using a slightly-different-than-recommended shade of embroidery floss for their "There's No Place Like Home" wall hanging or pillow. So don't be surprised if you feel really uncomfortable in a fabric store. I sure as hell did! And people make fun of geeks dressing up like Jedi for star wars premiers and waiting in lines for days to be the first one in the door for the 12:01 AM showing....

He touched on exactly which geeks you might find in a fabric store. Roleplaying geeks! Not just Star Wars fanatics, but trekkologists, otaku, and LARPers. Geeks are everywhere... you just need need the right eyewear to see them. []

DIY? Where? (3, Interesting)

The Fun Guy (21791) | more than 9 years ago | (#13053639)

All they did was take an LCD screen, designed to be used with overhead projectors, and put it onto an overhead projector. The only "DIY" was the case they built out of "partial board" and covered with black felt.

My department bought one of those transparent LCD screens in 1997, back when overhead projectors were still to be found in every lecture hall, laptops were $3000 and LCD projectors were $5000 and as big as a suitcase. The idea was to use this to go from the computer screen to the wall screen on the cheap. It was used every once in awhile, but if you weren't using a laptop, it was a pain to use, since you had to wheel in a cart with a desktop PC.

Once laptops got cheap enough so that they were commonplace, LCD projectors had gotten cheap enough that the department bought one and consigned the transparent LCD screen, with its terrible picture quality, to the back closet of the copier room. There, it collected dust, along with all of the other obsolete junk that no one wanted to use anymore, but had cost too much to just throw away.

The transparent LCD screen was an ugly kludge, a bridge technology to mate the old with the new. Let it die.

Nothing new here (1)

davidmcg (796487) | more than 9 years ago | (#13053650)

I seen plans for this on the web years ago. There's nothing here that hasn't been posted on 100's of websites already.

To All Those That Claim That This is Useless (1)

oblivionboy (181090) | more than 9 years ago | (#13053679)

I would suggest you just relax. Aside from the obvious, "MAYBE I WANT TO BUILD MY OWN PROJECTOR", excuse, there are some very good reasons for an article like this. For example, I have several older laptops sitting around. One of them is a Compaq that is powerful enough to play MPEG video at SVGA, but the backlite is gone. And even if the backlite was gone, I still don't use it because its a few years old.

So in fact I've been thinking of some uses for this machine, and I can see that this would be perfect. Anyone else that has an older laptop and doesn't mind pulling it apart to make a project could make one cheaply. It would then become a dedicated video playback system. With Project. Great for parties!

People on slashdot do have parties don't they? :) .o.

My only question about this... (1)

rAiNsT0rm (877553) | more than 9 years ago | (#13053710)

Is that I remember in college a professor of mine using one of these overhead LCD projector doo-dads and she had to constantly turn the overhead off while lecturing because the heat of the projector would start to "burn" the LCD and the image would be distorted on the screen. After cooling down it would work again, but still during a 2+ hour movie or gaming session... I just can't see how this will work.

Now overhead projector technology may have come a long way (hehe) since then but isn't this an issue? At the very least, especially when it is crammed in a felt-lined box.

Anyone know?

Proxima 944+? Unobtanium. (3, Informative)

larsoncc (461660) | more than 9 years ago | (#13053750)

According to this link [] the Proxima Ovation 944+ is 8 grand new. Not that anyone would pay that, right? Well...

None are listed on eBay.

Finished auctions on eBay list at about 300. [] That's fine, but try to find one!

Kind of eliminates the ability to do this project, doesn't it?

I don't understand why all of these DIY projects have to use some amount of unobtainium. Why not price out some NEW parts, ones that are currently on the market? Leave it as an exercise for the reader to find used or discounted products.

Only then can you make a fair assessment of whether or not one of these projects is "do-able."

I would love to see some names / brands of recommended overhead projection panels - but unfortunately, THAT is left up to the reader. I thought making these recommendations was a key part of a DIY article. After all, look at Woodworking magazine or any other DIY magazine - they all list the parts, the specs of the parts, and typically, a price or two with each.

Real LCD Projectors (0)

Anonymous Coward | more than 9 years ago | (#13053782)

Real LCD Projectors actually use three seperate panels with each panel reproducing a primary colour. The light source is filtered into the primaries. Each colour then passes through its own panel and the image is recombined and then projected.

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