Project Screen Onto Wall

[NNNOOOOOO 0]

I have two convex lenses of different unknown focal lengths to do it with. I also have two concave lenses of the same unknown focal lengths. Those two, however, cannot separate. How do I project the image on my game onto my door.

[rvalkass 5]

Are you planning to put the lenses in front of the screen, and use the screen as the light source? Unfortunately I don't think that will be bright enough to project onto a wall at any size considerably greater than the screen size. Projectors use much brighter bulbs to create their images.

[NNNOOOOOO 0]

That was the plan. Using only one lens, I could get it to project onto the wall. I t would either be smaller than I wanted and blurry, or just the right size, blurry and inverted. I would add the second lense to focus it and re-invert the image, but it always came out too blurry to tel if it was re-inverted.The game has 4 brightness settings.

Edited July 15, 2011 by NNNOOOOOO (see edit history)

[shadowx 0]

I highly suspect the poster above will shortly change their signature to spam links.a monitor will not be bright enough to project anythying, the only way you could get any kind of shape out of it would be to enclose the screen in a dark box ensuring no light can escape and then mount the lenses at precisely the correct distances.The projectors we have here use a massively bright bulb to project an image onto a wall just 30ft or so away, so bright that they come with a warning not to look at the light, if you do then you get bad sunspot type effects for a good 10 minutes, and thats just accidentally getting a glimpse, if you stared into one you would probably get severe eyesight degradation at least temporarily. using just the backlight on a monitor will only get you, at the very very best a projection similar to the size of the screen a few feet away, and even then it will be dim and so blurry that you wouldnt be able to identify large icons let alone text or characters in a game.

[NNNOOOOOO 0]

I highly suspect the poster above will shortly change their signature to spam links.
a monitor will not be bright enough to project anythying, the only way you could get any kind of shape out of it would be to enclose the screen in a dark box ensuring no light can escape and then mount the lenses at precisely the correct distances.

The projectors we have here use a massively bright bulb to project an image onto a wall just 30ft or so away, so bright that they come with a warning not to look at the light, if you do then you get bad sunspot type effects for a good 10 minutes, and thats just accidentally getting a glimpse, if you stared into one you would probably get severe eyesight degradation at least temporarily.

using just the backlight on a monitor will only get you, at the very very best a projection similar to the size of the screen a few feet away, and even then it will be dim and so blurry that you wouldnt be able to identify large icons let alone text or characters in a game.

I'm not trying to project a computer screen. I'm projecting this:
http://forums.xisto.com/no_longer_exists/404.png


It has four brightness settings. The room I'm trying to project it in is almost as dark as it can be. And the wall I'm using is about 4 feet away. I can get it to project into a large image, but it is inverted and blurry.

[shadowx 0]

The inversion would be dealt with by adding an extra lens i believe.The blurriness will be one, or both of two reasons:Either the light source does not have enough contrast (IE you need a brighter source with darker blacks)or the lenses are imperfect/badly aligned.I would guess it is both in this case.

[NNNOOOOOO 0]

The second one is definitely a problem, as the only thing holding the lenses are my hands. As for the first proposed problem, I'm still thinking it is bright enough, but where the lenses have way different focal length, that might be a problem. I'm going to get a couple of (30?)mm lenses from my moms camera case and see if I can get anything else to happen.