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Screen With 180 Degree Field of View
emj writes to tell us project jDome has started actively soliciting consumer feedback and, of course, donations. They are currently promising to deliver their "180 degree FOV monitor" this year for a pricepoint of around $200. The videos and talk have been circulating for the last couple of weeks or so, but they have added a video of the supposed tech in action. Buyer beware, but I would love to see a couple of reviewers get ahold of this and let us know what the story is.
I just watched the video and it looks to me like all the have done is stretched the standard view to fill the 'dome'. This results in all objects that are at the edges of the dome to be stretched and way out of proportion. The "man at the right" is a prime example of this.
Undetectable Steganography? Yep, there's an app fo
It's a $200 white, round umbrella. Then you still have to buy your own projector? I don't see anything new, apart from a new use for an umbrella.
...although it might be possible with a pixel shader, the hardware would really need to support other projection types than just standard 3-point (and with some hacking the transformation matrix, 2-point) perspective.
For a dome projection, you essentially need a linear fisheye projection out of the card, and the cards just don't do that.
You could do it in software, render a hemicube in the buffer, use a pixel shader to map the appropriate pixels onto the circle, done. Except that to get to 'done', you have to go through some very expensive (in terms of performance drop) steps.
1) rear projection onto a deeply curved screen? Getting even illumination at the edges, where the light is striking at an angle, is going to be quite a trick, due to Lambert's law.
2) How are they going to avoid the problem of washout and reduced contrast due to light from one side of the screen reaching the other side? This is always a problem with deeply curved screens. It's very noticeable in IMAX Dome (Omnimax) screens. The only system I've personally seen that avoided it was the original Cinerama screen, which was a very specially built screen made of hundreds of individual strips. And that only worked because the screen was huge and you were sitting very far from it.
Cinerama and IMAX screens are huge and far away. They're almost at optical infinity. The texture of the screen is invisible. There's very little binocular depth cues to tell you that you're looking at a flat screen, and if you move your head (as you always do unless it's in a clamp), that doesn't give you any parallax cues to speak of. This means that the screen itself is hard to see, and there are practically no binocular depth cues. That in turn means that there's nothing to contradict the numerous depth cues you get from any flat picture (light, shade, interposition, etc.--see any perceptual psychology text). The screen itself falls away, the non-binocular depth cues dominate, and you have a distinct feeling of being in 3D space.
But this is a small screen a short distance away from you. That means:
a) The texture of the screen may be visible unless they're using some rather special screen material.
b) Again, because it's a small screen a short distance away from you, there will be enough binocular disparity between your two eyes for you to form a stereo image: that will tell you that you're looking at flat image in a bowl, and in the battle between those cues and other cues, it's not clear which will win. The same thing will happen when you move your head. In fact, if you move your head a few inches, you will probably be far enough from the center, as a percentage of the radius, that the image will show geometrical distortions.
I am very, very, very skeptical that this system will produce a high-quality 3D-like image in the way the IMAX does, or Cinerama did.
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Im not sure where this is coming from. I bought a mitsubishi 720p project for $800 over a year ago, and aside from a few key difference its pretty much equivalent to an lcd tv.
The main hassel with a projector is that you need a sound system and you have to deal with light levels.Keep in mind that whatever your wall/screen looks like is what blacks are going to look like.
I was worried about bulb burn out when I got my projector, but out of the projected 2000-3000 hour lamp life, ive only clocked ~650, so in my case ill likely replace the projector before the bulb.
If you can take care of all that then its basically a 90+in lcd tv for a fraction of the cash.
Some people mention resolution concerns, but for console gaming almost no games render at anything above 720p. Even games like gta4 that support 1080p just upscale.
If 1080p movies or PC output are a requirement then theres always 1080p projectors, their still around $2k but that price has been dropping quickly. I assume if youre playing Crysis at 2560x1600 that price is no object.
You can find your own FOV:
1. Draw two dots on a white board and measure the distance between them
2. Stand in the middle of these two points, but far away from the board
3. Start moving closer until the two dots disappear from your vision (of course, keep looking in the middle)
4. Measure your distance to the board when the dots have disappeared
5. Use middle-school math to figure out the angle
I found mine to be roughly 120 degrees
Change is inevitable, except from a vending machine -- Robert C. Gallagher