DIY Home Theater Projector
So DIY home projectors are nothing new. For years people have been trying to make their own projectors due to the high cost of real LCD projectors.Home theater receivers and a strong stereo system, along with this projector can make you feel like you are at the movies. So what makes this guide practical? Simply put, the theory behind projection coupled with the breakdown of costs for each main component of the projector. We let you decide what components are right for you, but give you a fully functional example.
We have been nearly overwhelmed with fan mail over the DIY Projector project. We have also received a plethora of questions on panels (would this make us in-famous?). So instead of answering 5 billion emails individually we put this break down on panels together. We have hand tested each model shown and will update it frequently.
The theory behind projection:
The principals that make projection in general possible are very simple in concept. You need simply 4 requirements to be met: a light source, the brighter the better; some form of imagery medium, film or LCD it’s all the same conceptually; a focusing mechanism to help provide a crisp image; and finally a display medium. There are many ways of accomplishing each of these requirements. We will be glancing over them and providing some examples that could fulfill the requirements for our LCD Projector.
The Light Source – The LCD Projector Bulb
Back in the day traditional carbon arc were used in actual film based projection, but modern xenon arc lights are now more common. Xenon’s were introduced in the 1950s, they are safe and easy to use, and are relatively cheap. Most all LCD based projection use Xenon or filtered Metal Halide, based light sources. Commercial or non DIY projectors can have bulbs that are very very expensive, often in excess of $500.00 for a bulb that usually can only last for 2000 hours. All bulbs are sensitive to shock, getting bumped too hard can be a costly mistake. So what are the most common practical light sources?
Xenon Light Source
|$20 – $150|
Construction Utility Lights
|$50 – $250|
Modified Automotive Head Lights
|$10 – $40|
|$10 – $150|
|$20 – $100|
The Imagery Medium – The LCD Projector Panel
Historically, cellulous based films were used as the imagery medium. Light passing threw the film, and interacting with a shutter created the viewable content. LCD projectors act on a similar principle. Light passing threw the LCD creates the viewable content. There are many ways of using LCD‘s of many verities. Now, here is where I have to return to the point that this may not be the first how-to article. There are a lot of articles with little to no foresight in this type of project. Picking a cheap LCD monitor off the shelf for instance is a bad idea. Normal LCD (Liquid Crystal Display) are not designed to be used in high-heat environments. Using a cheap LCD panels can result in nothing more than an expensive paperweight. The seal around the edge of the monitor can crack or become damaged allowing the liquid layer between the layers of glass to dry out and become worthless. Secondly, there are many DIY attempts to fulfill the requirements of an inexpensive monitor with a small (4 inch or so) LCD panel. The problem with this is most small monitors have only 250 or so lines, so you may as well throw the image quality out the window. These methods do work, they just are not very effective compared to similarly priced solutions.
The Focusing Mechanism – The Lens:
Arguably the most important part of the projector, the lens allows the transition of light to projection medium. The quality of the lens you use is of utmost importance as it will directly affect the image quality of your projector. If you get a scavenged lens, be sure the lens is not scratched, and inspect the lenses for any coatings. 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.
The Display Medium – The Screen:
In most cases you will need a reflective surface which may be either treated with aluminum (for higher contrast in areas with ambient light) or a white surface with small glass beads (for high brilliance under dark conditions). Using a painted wall is usually not a good idea. Most paints are gloss or Simi-gloss and reflect and diffuse the light and there for color away. There are several ways to get your screen setup. From wall laminates to wall mount dropdown screens, to portal tripod based screen.
Overview So, what did we choose as the best solution? We chose the cheapest option, that just so happens to out perform many of the other combinations. But ultimately as this is a self funded site, I choose the cheapest way to do it. Which I think, oddly enough, is what the majority of visitors would want any way…
|LCD Projector Pannel||$25.00|
The overhead Projector:
This is a really basic Overhead Projector. Nice and bright. In fact, it’s bright enough to project our content on to the side of large buildings. Another big bonus is the fact that the bulbs are comparatively very long life, and at $10.00 each compared to the $500 variety, I would say they’re a no brainer. Also we got this unit very inexpensively. We hunted at school surplus, eBay, local business surplus equipment shops and found this and several others at a local thrift store. The only down side is that it is a little bulky and not very quiet. This can be addressed by a custom enclosure. By building a custom enclosure we can cut the noise to about nothing, prevent light leaks, and make it look much better. And if done right, we will have a great place for some sodas and a bowl of popcorn between a couple of lazy boys.
The LCD Pannel:
We chose the LCD Panel for a few reasons. First off its ready to go, out of the box, for what we needed. They are cheap and readily available on eBay and other online sources. They have all our vga, composite, and s-video connections ready on-the-spot. The image quality is really exceptional with these units as they are basically a 15″ LCD monitor without a backlight. And it was instantly and universally compatible with our projector. Now, we chose the Proxima Ovation 944+ as the unit of choice for us. It natively supports 1024 X 768, and supports about any aspect ratio and refresh rate you could dream of. Now I wouldn’t play UT2005 on this competitively as all LCD monitors (with a few exceptions) are far too latent to really game on. Nothing really compares to the good ole CRT when it comes to gaming. But it is really good for the console games I found.
This is really a simple and basic part of the project. 4 sides. The rear with hinges. And the front with a hole and some glass, nothing too special here. We did line the inside with black felt after some experimentation and found it handled the light pollution and sound dampening allot better than just black spray-paint. A couple drinks on top and we’re all set.
We chose the ELITE SCREENS M100UWH 100″ Manual Projection Screen from Newegg.com for $110.00 for this project. The material this screen is made from allows for viewing from a relatively broad range of angles. It is a manual pull down type of the screen (for now…) and can be mounted on the wall or from the ceiling. It is also flame retardant, and will support the 16:9 aspect ratios (HDTV) natively! 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.
All the other main system goodies:
Items we used in the setup and testing / use of this system include but are no limited to…
Building the case:
Assembly of this project was really simple. Basically just making a cube with a hole on one side, and a hinged door on the other. A little glue and some screws. Slather it with some paint. Let dry (optional) and that’s about it, instant bird house! Oh wait. The only tricky part about the construction of this is using a drill to make some holes in the bottom of the case for air flow and the window. Now, our overhead projector’s lens assembly just so happens to be centered over the projector. We did, however, find in our hunting some that were a little off to one side or the other. So just watch for that. Now as one of the main reasons for building this case is the dampening of sound, we decided that a window needed to be installed to provide some sound leak resistance. Initially we used some plexi as that was just lying around. But after some testing we found it distorted the image more than we liked. So we chose some real glass. Cutting glass was an interesting thing to learn. If you cut your own just be real careful. Finally take some scraps and glue them to the bottom to help with airflow, and cut a small notch in the bottom of the door in the rear to allow for cable access.
Finishing out the case:
So, after you have all the construction of the case done, we will be doing 2 final things to it to help address the light pollution and sound pollution, just to make sure its not an issue. And while these steps are not necessary, we do recommend that you entertain them at the very least as a option. 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…. any way, simply put, get some black felt from the ole fabric store. It comes in a small patch and large sheet verity. I recommend getting one large patch and cutting it to fit. With some adhesive spray (don’t use contact cement like I did), spray the inside of the case and stick the felt to it. It’s as simple as that. Noise and light issues are much lessened.
Sticking the stuff into the case:
So after the paint and glue has dried we took the equipment and stuffed it into the case. I used some adhesive Velcro to affix the panel to the projector just in case… This is a good chance to take and turn on the projector and do some basic testing to make sure your rig is set up right and that it blocks out any light leaks. With the unit closed, check for sound leaks and use some extra felt to try to improve this. One thing I also did here at this step is make sure the holes in the bottom of the case are not obstructed by the felt. Turns out I forgot to clear the holes, but quick cut with a sharp x-acto blade and it’s all better. Let the unit run a while and pay attention to the temperature of the case. Address any problems before we get the other electronics into it.
Mounting the screen:
So this turned out to be the hardest part of this entire build: finding a place to mount it, finding the studs to screw into, and finally getting it set on the wall. The screen is 18 Lbs and therefore needs to be well mounted. Don’t do this alone if you can, it really would make it a lot easier with some help… trust me.
So the final step for setup is really simple as well. Place the unit where you want it, focus it, make a few tweaks in its position and plug in your speakers, I used the Logitech Z-5500 and I have to admit I really was impressed. Plug in your media gear. You can have your DVD or tunerVCR hooked up as well as a composite feed and an S-Video feed all at once and just select your input on the unit. Fire up the lamp and tweak the color and contrast setting to your liking.
Finding some cold ones:
Sometimes with the inventgeek projects the testing and configuration section is the bane of my life! Getting this or that to work when something stupid was overlooked… it can drive a man, or even a geek, crazy! But with this project the testing phase really had more to do with finding some cold ones and enjoying! I mean I think I did sweat a little… that Gollum is just so tricksy!
I will be honest, this was a really easy project, almost too easy. I mean, I am a little disappointed as I didn’t even get my dremel out. But as you could see from the theory page of this article it’s really easy to convolute and overpay for something that is actually really easy to do. So do I think it was worth it? Well for under $200.00 it’s a no brainer. The only real downside to this unit is it’s a little large and bulky. But even that could be notably compacted simply by taking the projector apart and the lens system apart and building a smaller case. But I wanted to show how easy and inexpensively this could be accomplished by some one with limitedfabrication skills. 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 think I will be looking into the whole building projecting idea a little more as well. Making a mobile gaming system in a car with some wireless networking could be real cool to do with the local chess club or SCA group. Speaking of the chess club, im late!
Have fun and one last peace of advice to all you geeks out there. Do not touch the bulb when the projector is turned on! Just trust me on that one.
So here is the deal with the donate link. Inventgeek is solely funded out of my pocket. When I publish these articles most of you visitors from to my site come from Slashdot, digg, makezine, hackaday never support the sites existing revenue streams on the site or others. I have reached a critical mass that I never wanted to reach but frustratingly I have. Our revenue stream has been on a steady decline as our traffic has been on a steady incline and our projects are no longer making me take just minor losses. I don’t want to pay for new projects any more. This site is for you the world. Our projects are for all our visitors to see and be inspired to do. Go invent something I always say. But the sad truth is we (I) may have to stop with the free ride folks. So were asking for donations. It’s totally voluntary but without it at this point we will not be doing many more projects. The alternative is to sell out just every other site and bombard you with more intrusive ad’s than content.
I have received an amazing response to the diy projector article. So to help all you out there building your own here is some additional information you may find helpful.
Let’s clear the air about aspect ratios and resolutions first off here.
There are two contrast ratios that you need to be aware of. 4:3 and 16: 9. Simply put the 4:3 is normal TV (you know the crappy DVDs you buy that say “this crap has been edited to fit your screen.) wide screen is 16:9 and is the obvious choice id you can get your hands on it.
Resolution seems to be a point of some serious misunderstanding. So here are some fact on normal TV and HDTV. No matter the TV or tube all of the signals here in North America is bound to a standard. NTSC stands for the National Television Standards Commission, and they are responsible for the standard format of television in North America. NTSC has a pixel aspect ratio of 720 horizontal lines and 480 vertical lines. So basically what this means that that is the absolute top of the performance achievable from the format. In a normal TV signal there are 240 vertical lines and 360 horizontal lines, with a display frame rate of 29.97 frames per sec at 60Hz. In HDTV equipment the best there is so far is a Toshiba tube that can do 600 lines. Realistically that means that an 800X600 LCD panel will suffice for both applications.
So after all this mail I have been trying to get my hands on all the lcd panels I could to test them first hand. Below is what I have for now, I will add to it as I can. This should answer most of the questions on acquiring them. Ever since the DIY projector article went live there has been a mad rush on the projector panels, and they are currently selling for more than there worth according to the past months sales. If you need more direction on finding them use eBay, Froogle or Google. Don’t email me asking me to research them for you, if you cant Google it your self your not qualified to build one.
|Model||Base Resolution||Comments||Est. Price|
VGA & S-video
|Slow Refresh rates, 2 million colors, moderate contrast ratios….||20 – 60|
|Ovation 820||VGA & S-video
|Fair Refresh rates, 2 million colors, Fair contrast ratios…. Vivid Colors.||40 – 80|
|Ovation 844||VGA & S-video
800 X 600
|Fair Refresh rates, 16.2 million colors, typical 100:1 contrast ratios…. Vivid Colors.||40 – 120|
|Ovation 946||VGA & S-video
800 X 600
|Fair Refresh rates, 16.2 million colors, typical 100:1 contrast ratios…. Vivid Colors.||50 – 180|
|Ovation 944||VGA & S-video||Good Refresh rates, 16.2 million colors, contrast ratios vary with revision, 200:1 or 100:1 and clear vivid Colors.||60 – 200|