I agree. I also think the centre would be a hot spot with the outside being dim, I think the resolution would be questionable, and the light output would be dim. I would like to hear a review of someone that has done it.
Haven't built it yet. You can buy the lens at Office Depot for around $5.00. It's basically a full page map magnifier.
I did place the lens out in a dark room about a foot or so from the Television and it did cast an image. It wasn't very bright, not terribly clear, but it sure was BIG! It took up the entire back wall in my bedroom. And that was without yet building the projection lens housing and increasing brightness, tweaking etc.
Will it produce an acceptable image? Most likely not, or it would be utiilized by manufacturers. The single tube projectors from the 80's all cast dim images, which is why the three tube system became popular.
I'm sure it wouldn't exaclty be hi-res or 1000 lumens of brightness, but I'd still be interested to find out first hand just how bad the image is. I mean if you're going to project something like the superbowl just how good does it need to be?
I actually created one of these "projectors" with the "fresnel" lens from Office Max about 6 months ago. I saw all of the ads on ebay when I was looking for a projector, so I decided to start making one on my own.
I just took a large box cut it down to fit around the edges of my TV screen (a 13 inch sony flatscreen) so it was basically a rectangle open on both the screen side and the oposite end.
I then put the fresnel lens with some matting in the end opposite of the screen and slid it back and forth.
While it did project an image on my wall about 15 feet wide from 12 feet away, it was not very bright. My EIKI LC7000U produces a much brighter image.
The image itself was very blurred around the outside edges. It was kind of a trade off... Either outside blurriness, or make the outside clear and the center would be blurry.
Cheap solution for children entertainment however, without wasting bulb hours on cartoons.
I was thinking about doing it up again for Video games or my bedroom, because they are quite easy to make.
To be honest with you, I have never seen the 80's projectors.
Well, Actually, I remember seeing a projection TV for a superbowl a while ago...It had 3 crts that projected on to a mirror then onto an attached screen. I would say the image was comparable to that.