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Harrods Sells Holographic TV
beuh_dave writes "Harrods is selling a holographic TV, CLARO, for £15,000. The Holoscreen is a revolutionary holographic film which displays any image fed through a projector at a specific angle on to a transparent display. All other light is ignored. The result is a remarkably bright and sharp image quality - even in brightly lit environments."
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This isn't really "holographic" in the sense of a 3D image in space, or a perception of a 3D image.
All it is is a screen that hangs in space (or supported by glass as in the site) and only shows images directed on it from a certain angle - from a projector sitting conspicuously on the floor behind it.
It's pretty, but hardly world shattering.
RST
Rear projection onto a transparent screen. Kinda cool but not worth £15000, not by a long shot. It seems to me to be a case of them mixing "can do" up with "should do".
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Why call a beamer 'holographic television'?
From the article (which is rather lacking in technical details), the display sounds like a holographically-recorded diffractive optical element on a glass substrate. If so, I'm curious how they compensate for the dispersion intrinsic to the diffraction phenomenon (since selling a 15,000 quid monochrome display is probably not a commercially-viable option :-p). Also, since the display claims to be angularly selective (it has to be if it only accepts a specific projection direction), I wonder if it has a similarly selective viewing angle (like early LCD displays, which were only bright and clear at normal incidence).
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why dont you shine a projector towards a mirror and have a look what you see in the mirror, thats right! a projector!
Given the way this thing works, it has to sit somewhere in the middle of the room. That is not a good place for a display or TV; it is an even worse place for a transparent piece of glass (because you are going to run into it and knock it over).
I'd like to know how much these devices will cost elsewhere. Harrods have a reputation for inflating prices above and beyond high street level. For example, a toy that costs £10 in every other shop is selling for £25 in Harrods. You are paying for the experience of shopping in the store.
First of all:
Given we are talking about how wonderful this new tech is, how much contrast it hat - how about some contrast on the freaking article! Come on, grey text on a white background? Obviously we now know where some of the layout people from Wired Magazine went.
Second of all:
The pictures in the article look too damn good - I smell retouch. If you want to convice me of the value of this technology, you need to show me a movie of the produce in use, as the camera moves around the room. After all, I can take your average rear-projection TV and make it look fabulous, IF I pick the camera angle to maximize the brightness of the screen. But as anybody who has ever looked at a rear projection TV knows, the "sweet spot" of the image is very narrow, and if you leave it, the image fades tremendously.
Third of all:
The single biggest cause of loss-of-contrast on a light sourcing display, be it a projector or a CRT, is the fact that the light in the room is reflected from the screen, making the blacks of the image not black. Now, this display may be wonderful at redirecting the light from the projector, but if the "glass" is clear, and the wall behind it is NOT black, then the blackest the image can be is the color of the wall behind it. If you wanted to truly get deep blacks, you would need to put something like black velvet behind the glass, to absorb the ambient light.
Fourth of all:
Back to the viewing angle issue: holographic techniques usually are VERY angle sensitive - the diffraction grating allows light from a very specific angle to be redirected to a very specific angle. Is this image REALLY viewable from more than one or two places in the room?
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