Projecting CRTs

[AKA_RA]

Is there any way i could possibly project the image off of a CRT monitor onto a surface with a bit of clarity. Im not thinking of watching my DVDs on it. I'm experimenting with lighting options and im looking for something that could get colored patterns on a surface/object without using a projector. Ive seen many DIY ones using LCD monitors, but thats out of my price range currently. In the long run thats exactly what im going to do, but for now, any suggestions for using an old CRT? possibly focusing the image using a lens and if needed, defuser of some sort?

[silverdemon]

I don't think you can. CRT have a vacuum inside them and that's not for nothing. When you remove the vacuum the elektrons will not bend to the right position and you wont get a nice pattern.
I think...

[tybrenis]

You might be able to as long as you have a flat screen CRT. I don't see why not, as long as you aren't disassembling it or anything.

[AKA_RA]

definately not takin one of these apart. i enjoy my heart beating and my brain not being fried. heh. i was thinking more so having something in front of it, like a lens, to focus the image. no way am i taking one of these apart, and god forbid i ever attempt to actually open the tube. my guess is that if i could even get that far without electrocuting myself it would shatter/explode/implode/hurt me a lot, something bad. besides, isnt it basically a hot cathode tube that would cease to function the moment the vacuum was broken?

[silverdemon]

ok ok, sorry I didn't understand that...
yeah, a CRT will not function once it is broken :p :D ;)
but then again, I don't think it'll work how you have planned it...

you're probably better of buying a normal light and then put some colored plexi or something in front of it. though you won't get very sharp images then...

[crazybillybob]

The only way to "project" a CRT isn't really projecting It's refelcting. Best example is a Arcade game, there's a CRT pointing up in the bottom cabinet, there's a angled mirror in the back, then the plex that you look through they all work together as a system of mirrors that let you see the CRT.

Sorry that's the best I've got.

CrazyBillyBob

[AKA_RA]

Thanks for the input guys. Youre not exactly helping me solve my little problem, but your trying, and thats what counts. Lemme describe what im going for, maybe thatll give you a better idea as to how to help me out. ^_^

It's hard to explain, but ill try. I'm trying to set up a mini-rave like scenario. but i want it to be more than a crappy spiny light or laser on a wall thing. i want the walls to have constantly changing colors that react with the music. Imagine any visualization program projected onto a wall, ceiling, or an entire room where there may be funiture and other things. I know its easily done using projectors and the hardware i have now, problem is, im flat broke, so a projector is completely out of the question. as of right now the best i can do is point the crt at the wall and have a visual program on that monitor, problem is it just kinda ends up one color, or just white, id like the patterns to be noticeable, even if they are not clear. in fact id prefer them to be diffused or otherwise softened.

I plan on employing this method not only for parties, but for some video projects i have and on occasion just for casual use. it may sound like im over doing it, but when i relax and listen to music, i go all out. and i have a thing for lighting effects. prolly cuz of my work in theater(not acting, but stage/lighting/sound work) although I am extremely obsessive about the lighting. no lights in the eyes, and absolutly no strobes. soft light or backlighting is best. it seems like all my ideas i have are out of my grasp. theyre possibly but not with a budget of whatever i find in the couch.

for referance i have a 6600GT on the box im using for it, VIVO of course, i have at least 3 somewhat ok CRTs laying around and a TV or 3, heh.

my next option is a super cheap LCD that can be used in a similar way to the DIY projectors ive seen. remember, quality is not an issue. but ill start a seperate thread for that i guess, im already making it hard on you guys as it is, with all the typing and everything, heh. thanks again for your input though. it is definately appriciated

[Razors Edge]

Well, Its highly improbable that you can project form a CRT, but yet again Impossible is nothing...hehe

But from a stand-point view, The work you would have to put in projecting a CRT, you can just buy a projector. The amount of work and tools you put into the projectino CRT will apss how much you spend for a projector.

[jdbnsn]

AKA-
I think I know what you are talking about and off hand I'd say it can't be done, at least not to accomplish the effect you want. I have seen plans for home-built projectors and I don't know if it's the same as what you've seen or not but they involved removing the LCD screen from a monitor and projecting a beam of light from a halogen bulb through a series of optic lens and the LCD screen. I don't think there is anything you can remove from a CRT monitor that you would be able to project the light through and produce an image, but I don't know too much about CRT's either, just my 2 cents.

[EPYK]

you could actually project the image... only it the image is really bright and you have a mirror and a projection lens... im sure about the specifics but it is possible... this would be very similar to how a transparency projector

http://img267.imageshack.us/img267/1768/untitledcz0.jpg

[Omega]

How many of you know what CRT stands for?

it means...

Cathode Ray Tube. That's right, your moniter is a Cathode Ray Tube, just like the CCFL's in 80% of cases i see.

Now, you can't disassemble a CRT and magically make it project, but you can do the mirror to a lens technique, which will also flip the image (you're using a mirror, after all.)

That also means you'd have to concentrate the light to get it to hit right or merely just gat a giant-ass mirror and lens.

hope this helps,
Omega

[AKA_RA]

in not new to this. and no offense, but did some of you spend the time reading previous posts? im not trying to be mean, but its pointless to tell me notto do somehting after i said i definately dont wanna do it. example: i specifically stated there will be no opening of the monitor. please dont get mad that im pointing it out, i dont mean to be rude.

the lens idea is exactly what i was thinking, and yes, the LCD that refered to that you could use for a DIY projector is exactly what your talking about. i dont know why i didnt think to replace both the projector lamp and the gutted LCD with the CRT, sounds so simple now. ^_^ Epyks diagram shows it. except i wont need a mirror, im most likely going to be aiming the monitor right at what im wanting the imaging on. anyone know off the top of their head where to get a lens that would work? do you guys think any old lens would work since i dont need any real clarity, just not have the image somewhat focused and not just diffused.

as for anyone that ever says that something cant be done, you need to wake up and smell the bondo(not really, its kills brain cells). nothing is impossible, just really really hard sometimes. ^_^

One more thing in response to omega: please remember, you dont know much about who your talking to on these forums a lot of the time, so please dont talk down to other members, i persoanlly dont like it, and i dont think im alone on that. but also, please understand that im only saying this because im a defensive person at times and i feel you were questioning my intelligence. so lets drop this and pick up a dremel. ^_^

Edit: BTW Epyk, nicely done with the diagram ^_^

[EPYK]

if you plan on doing a projection with out a mirror then you will need to mount the crt upside down to get the right projected image... the lens will invert the image just like the human eye....

[AKA_RA]

good point, i totally forgot about that. lol. but really, its not important due to the intended use. im planning on heading downtown today to ask around at some places that i frequent to see what their input is on getting such a lens

[EPYK]

another idea this brings up.... what about projecting an illusion.... when i find the article i want ill post it... but you could make a box put your crt in the box and project the crt as a whole to an area at the top of the box preserving a 3 dimensional aspect

[CanaBalistic]

Ask and you shal recieve. I found this little gem a while back. Works with any tv and projects up to 100'' image on any flat wall. And it only costs $15!!!

http://cgi.ebay.ca/Turn-Your-TV-into-a-100-DIY-Projector-Lens-Plans_W0QQitemZ230046677812QQihZ013QQcategoryZ2914 QQrdZ1QQcmdZViewItem

[simon275]

Does it even work?

[AKA_RA]

ive got the same question about that as simon. does it work? it says lens and plans. looks like some guy got a bulk shipment and didn't know what to do with it. i would go for it. but ive never bought anything off eBay using non-american currency. do i basically convert it to american and pay that amount though paypal and they take care of the rest?

[FyreKnight]

I would also like to know how well it works, although it sounds like exactly what you need. As far as paying for it goes, if you buy it on ebay and pay with Paypal the conversion is automatic. For me Paypal merely charges the appropriate amount in Canadian to my credit card and converts it to whatever currency the auction was held in to transfer it to the seller. It's really quite painless.

Later
FyreKnight

[AKA_RA]

huzzah! i may get my idea working after all.

[EPYK]

cool, do it to it

[switz]

http://bigscreentv.20m.com/photo.html

Here is how you do it, in case you don't want to spend that.

or

http://www.i-hacked.com/content/view/47/94/

[d_stilgar]

Those ebay kits are usually ripoffs.

http://www.denguru.com/2004/11/13/supersize_your_tv_for_/

there's a good link for a guide that uses an LCD. The problem with a CRT is taht your room will have to be absolutely pitch black in order to see anything if you do the same project with a CRT. The LCD has light projected through it, the CRT will be relying on its own brightness, which is bright enough for you to enjoy viewing when it is on your desk. If all that light is diffused over 100"+ it will be very very dim.

[switz]

lumenlab.com

if you wanna do it with an lcd

[Luke122]

Sony used to make a projector (early 80's) that was basically a crt driven to super brightness, and then focused through a lens. It actually didnt work too bad, but the quality wasnt great. In a totally dark room, it was satisfactory to watch movies with a @ 100" screen, but any ambient light at all would ruin the picture.

So perhaps if you crank the brightness right up, and use a lens, you'd get a short throw projector, but you'd still have the bulk of a CRT to deal with.

[AKA_RA]

bulk of the crt isnt a big deal, its getting the image on the wall. and it doesnt have to be detailed, its mainly going to be a special effect kinda thing, just throwing moving colors onto a wall.

btw, i thought this thread was long dead, im glad its been revived...kinda, lol.

i may just look for a cheap projector, but it might not be worth the investment. the only thing id really use this for is adding dynamic light to a party/raves/my bedroom/etc

i think ill buy a cheap Fresnel lens and just mess around with it.