So... I wanna make my own video projector

[Zero Cool]

I've currently got the DVD player. Still gotta get the rest of the parts, but what I wanna know is what should I use as the light source.

I originally wanted to use LEDs, but found out that their lumens level is crap.

I heard of someone using a bulb from a halogen light.

But I found out that my local Ace Hardware has those energy-efficient bulbs, and those range from 500something to over 1700 lumens. But, aside from their mercury content (there's a place to take them in my town), I hear that they put off hellacious(sic?) heat.

But I plan on putting in a fan.

Someone wanna chime in?

What kind of light source could I use, that has lumens suitable for both indoor and outdoor usage?

Some ppl have made cheap ones for only $50, but mostly with stuff they already have. If I only have a few of the things, how much would it cost?

What other concerns am I overlooking?

And in case you're wondering... FM tuner built-in, but also there'd be audio output for external audio sources.

[snowpenguin]

Search on Instructables. You will find several 'Overhead projector' ibles on there, people who use an overhead projector an an LCD with backlight removed.

[bicostp]

An overhead will give you the widest choice of resolutions, since you can easily find LCD TVs that run at at least 720p that will fit.

However, I think your best bet is an old, used video projector. If the bulb is burned out, replace it with a Halogen car headlight, preferably a very bright one that puts out white light (not the fake HID blue ones or the really cheap yellow ones). There are a couple articles on Instructables that describe this process. (You'll want a projector that can at least 800x600 for regular NTSC video.)

[Zero Cool]

I'm NEVER gonna use an overhead projector. They are WAY too heavy. I need to be able to carry it from Point A (i.e. the living room) to Point B (either the back yard or an off-premise location, like someone else's house).

But if I do use one, which I won't, it'll be built around a broken laptop in lieu of a hacked-up DVD player.

And I have looked there... tons of times. I just want to hear more than a how-to from just a few cases. I wanna hear something that can totally take the place of the "Idiot's Guide to Homemade Video Projectors" that they should release but they won't cuz they're too good to do it.

Also:

A) Can I make it so I can alter the brightness of the light, so I can adjust it to the current light situation?

B) Is it possible to make a lens for making them project a 3D image (red/blue)? Can I do it with a dual lens setup?

[marshallh]

Most LCDs block a huge percentage of light coming through. You are going to need a REALLY BRIGHT light source. As in, so bright that it physically pains you to look at it.

I used a 300 watt halogen bulb in an old projector, the output was barely usable in a completely dark room.

[snowpenguin]

You could try taking the lens and light assemblies of an overhead and building them into a box, then replace the bulb with an incredibly light one.

[hailrazer]

About the only light source that works good is a 250 watt or 400 watt Metal halide lamp. The T15 is the best form factor because of the size.

Halogens are to hot and produce much lower lumens per watt than the Mh bulbs. They are also to yellow and will make the projection look bad.

You do not need an adjustable light source because even at the brightest you will be able to make it, you will still only get about 250 lumens max. So in a dark room it will be just bright enough and in a lighted room it will be not bright enough. So dimming it will do no good.

The basic design is a 400 watt mh bulb with reflector. A 220mm rear fresnel. The lcd. a 330mm front fresnel. A 317mm or 330mm triplet.

The box will need to be about 24" long and as wide as your lcd and as tall as your lcd.

[ZN13]

Try this.

That should answer a few a couple questions and also give you some ideas.

[Zero Cool]

So... using this particular Instructable, I plan on making one. Now, this person had a great deal of the stuff and spent $50 on what s/he didn't. Now, I only have the DVD player, so how much would the rest cost? If it's too much, I'll just buy this $100 projector from Heartland America.

And what lumens would you recommend for the following applications:

* Bedroom about 6-7ft long with a big window?

* Open-air backyard?

* Living room with two windows next to a kitchen with two windows (one big, one small) separated from living room by countertop? FYI, when you open all the blinds, it gets really bright, but when you close them all, it's comparable to a dark, cloudy day almost.

I ask because the Ace Hardware near me sells all sorts of light bulbs, and they sell three-ways that can reach just under 4000 lumens.

[snowpenguin]

Don't get the one you linked to at HA, it's a cheap knockoff with rectangular pixels.

[Zero Cool]

Don't get the one you linked to at HA, it's a cheap knockoff with rectangular pixels.

So... then I should stick to making one, cuz I'm not going to shell out something that needs to be supplied with impossible-to-find-outside-the-Internet lamp bulbs. Especially since even the cheap, refurbished ones are too expensive for me.

[hailrazer]

No bulb will work well but a Metal Halide. I have been building projectors for over 5 1/2 years and I have tried almost every light source available.

With a homemade projector you will get approximately 1/2 of 1% of the bulbs lumens through the projection lens. The reason behind this is the light loss through each fresenel (2 of them) at around 10% light loss from each. Then a Lcd has a 95% light loss, that's right it will only allow 5% light through. Then the triplet has 3 pieces of glass and blocks 10% light per piece.

So with a 4000 lumen bulb you will get around 20 lumens on the screen. Barely visible. With a 400 watt 40,000 lumen MH bulb you "might" get 250 lumens with an exceptionally good build.

Also that instructable will help you make a nice paper weight. The cheap magnifiers will discolor and melt and you will get a dim yellow projection that will make you quickly decide to throw the projector on the ole burn pile.

My 2 best projectors :
http://www.lumenlab.com/forums/index.ph ... opic=15796" onclick="window.open(this.href);return false;
http://www.lumenlab.com/forums/index.ph ... opic=20278" onclick="window.open(this.href);return false;

[Zero Cool]

No bulb will work well but a Metal Halide. I have been building projectors for over 5 1/2 years and I have tried almost every light source available.

With a homemade projector you will get approximately 1/2 of 1% of the bulbs lumens through the projection lens. The reason behind this is the light loss through each fresenel (2 of them) at around 10% light loss from each. Then a Lcd has a 95% light loss, that's right it will only allow 5% light through. Then the triplet has 3 pieces of glass and blocks 10% light per piece.

So with a 4000 lumen bulb you will get around 20 lumens on the screen. Barely visible. With a 400 watt 40,000 lumen MH bulb you "might" get 250 lumens with an exceptionally good build.

Also that instructable will help you make a nice paper weight. The cheap magnifiers will discolor and melt and you will get a dim yellow projection that will make you quickly decide to throw the projector on the ole burn pile.

My 2 best projectors :
http://www.lumenlab.com/forums/index.ph ... opic=15796" onclick="window.open(this.href);return false;
http://www.lumenlab.com/forums/index.ph ... opic=20278" onclick="window.open(this.href);return false;

So... can you point me in the direction of a better how-to? And I'd rather buy that HA "knock-off" than spend too much on something I'll more than likely screw up completely. And while the projector is crappy, is it a decent model for it's price? Or should I look elsewhere? Cuz ChinaVasion has cheap yet decent ones for over twice as much.

[bicostp]

That ChinaVision link goes to a parked domain.

We have a somewhat old InVision LP330 my dad got for free from work (they threw it out because they bought a shiny new one with a remote control ). You can probably find a decent used one for under $200 on eBay.
http://shop.ebay.com/?_from=R40&_trksid ... Categories" onclick="window.open(this.href);return false;

Even those really old projectors that are the size of a large suitcase will do fine for DVDs and TV. You can probably find one cheaper than that.

[marshallh]

Get a used, working projector on ebay.

A few years ago I bought a 1500 lumen, XGA 1024x768 projector with DVI, vga, s-video and composite inputs for $200 of ebay.

It worked for several year, after many hours of playing games with friends, movies, etc. It was $200 well spent, and there's no way you can match it with DIY for that price.

The bulb finally burned out (either that or the ballast died) and since bulbs are several hundred dollars, just get another $200 projector.