I'm new to the scene... Say about 2 days... And I was wondering about a design I thought up:
Would it be possible to just cut the light and fan from an overhead projector and use what's left with a tv, kinda like the lcd designs, but with the tv BELOW the glass that the OHP LCD sits on facing up.
What I'm trying to get at is: Is this possible, If so will I obtain a good picture and roughly how big with say a 14" tv? Brightness doesn't matter, I'll sort that out in the future.
Aside from brightness and size, heat wouldn't be a problem because of the light being replaced with a CRT.
I have included a small diagram to show the layout.
Would it be possible to just cut the light and fan from an overhead projector and use what's left with a tv, kinda like the lcd designs, but with the tv BELOW the glass that the OHP LCD sits on facing up.
What I'm trying to get at is: Is this possible, If so will I obtain a good picture and roughly how big with say a 14" tv? Brightness doesn't matter, I'll sort that out in the future.
Aside from brightness and size, heat wouldn't be a problem because of the light being replaced with a CRT.
I have included a small diagram to show the layout.
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I've thought about doing that but every time i fliped my tv on its back side it turns green. go figure. You would probably have to use one of those true flat screen tvs, the curved ones might give you fuzzy edges.
ap0the0sis
ap0the0sis
ok that's slightly strange... mine does not do this but dyou rekon it's unhealthy for a tv to be on it's back? i can't see any way around it, but i was going to suspend mine from the projector in some kind of frame or something.
also, wouldn't the fresnel lens flip/invert the image? like in those 100" DIY projectors which meaning all your text would be backwards....
not a good way to watch a movie
ap0the0sis
not a good way to watch a movie
ap0the0sis
you would have problems with lighting and get the dredde screen door effect. This the 100" screen that people keep talking about.
you wouldn't get screen door with a set up like this. all you would have is a very dim blurry picture. Only projectors that have screen door are DLP and LCD.
ap0
ap0
on ohp the text is correct because your on "top" of the fresnel, your talking about putting the tv "under" the fresnel meaning you will have a inverted picture. take out the fresnel and put it in front of the tv. thats the image you'll get. if you can live with it fine , go for it.
ap0
ap0
yeah an inverted picture would be fine to start with, i'll find a way to invert it back after... maybe a lens (concave?)
In my experience with the 100" tv projectors, same concept as what you're thinking up I had an upside down and flipped picture. Meaning I had to turn the tv upside down (green image) and use mirrors to flip the image so that the text would be correct. The picture was very blurry and dim, to the point it was unwatchable. You say you dont need a sharp picture but you WILL want a sharppicture if your going to invite friends to watch something.
Once you see how badly this projector setup works you'll go the lcd route. OHP + LCD panel will give you the best image for a budget of $150.00 or so.
ap0
Once you see how badly this projector setup works you'll go the lcd route. OHP + LCD panel will give you the best image for a budget of $150.00 or so.
ap0
as i mentioned, i'm just testing at present, but i take your point that if i actually want to USE the thing i'll need an lcd layout. The downside is i'm 16 with no money!
-edit
Although the projects I have seen using LCD look almost cinema quality when done right, but maybe that's just deceiving images
-edit
Although the projects I have seen using LCD look almost cinema quality when done right, but maybe that's just deceiving images
I dont think that will work
I tried taking a head from an overhead projector and holding it freehand above the TV like that.
Don't even try this idea you won't be happy. I could barely notice an image in pitch dark using this method.
I tried taking a head from an overhead projector and holding it freehand above the TV like that.
Don't even try this idea you won't be happy. I could barely notice an image in pitch dark using this method.
i don't know if i am correct, but i THINK you require the fresnel lens in order to direct the light towards the head which would explain the barely noticable image in the dark
oh, and does in help with any design if you turn the brightness up full on the tv?
oh, and does in help with any design if you turn the brightness up full on the tv?
when looking at screen shots use them only as a reference. They usually show a much better picture than is actually projected.
lcds' give a very good watchable image. expecially if you were to use a lcd panel with 800x600 or better. i've seen some panels on ebay for for as little as $25 - $50 and a cheap OHP can be found at a yard sale, school sale, surplus stores, ebay for around $50.
Obviously the lighting in most OHP are no good and must be replaced with a MH setup. This can cost around $50-$75.00 so in total you can look to spend about $175 - $200. Trying to put something together for less than that can give you bad results and you'll just be wasting moneys.
You can always get lucky on ebay and buy an lcd projector for under $200.00 ( hard to come by but i've seen them) and as bad as these projectors are they will give an image just as good as a DIY or better.
ap0
lcds' give a very good watchable image. expecially if you were to use a lcd panel with 800x600 or better. i've seen some panels on ebay for for as little as $25 - $50 and a cheap OHP can be found at a yard sale, school sale, surplus stores, ebay for around $50.
Obviously the lighting in most OHP are no good and must be replaced with a MH setup. This can cost around $50-$75.00 so in total you can look to spend about $175 - $200. Trying to put something together for less than that can give you bad results and you'll just be wasting moneys.
You can always get lucky on ebay and buy an lcd projector for under $200.00 ( hard to come by but i've seen them) and as bad as these projectors are they will give an image just as good as a DIY or better.
ap0
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