Laser projectors general? [zero lag & zero blur!!!]
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Re: Laser projectors general? [zero lag & zero blur!!!]
Yea I'm not sure I see the connection either. The wider the gamut, the more metamerism raises its head. Increasing the number of primaries (for any gamut) can reduce metamerism (in the extreme, you'd use hyperspectral imaging to record information, and a display capable of generating an arbitrary spectral signature at each pixel).
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Re: Laser projectors general? [zero lag & zero blur!!!]
Typical primaries used in most gamuts don't follow the entire range of possible colours. I meant the example of a mega-number of primaries in Pointer's Gamut as an example of how to achieve a similar measured spectrum as to what the eye perceives, and since lasers have narrow bandwidth you could increase the control over the entire range of primaries simply by adding more lasers.
So long as they don't overlap you are golden. Many DLP projectors use yellow / magenta / cyan / other primaries in their colour wheels for this purpose, but of course they lose brightness because that cuts out the duty cycle of light for the other colours.
However for simultaneous lasers that is not a problem, your white brightness is the same as your colour brightness and then you can emulate every possible permutation of wavelengths and intensities at each of those, if you can cover the entire visible frequency spectrum with individually modulated lasers and the appropriate mixing / modulation logic.
This is why I suggested using a 16 bit float ACES or XYZ color input because that would be translatable to theoretically any visible colour, even far beyond rec 2020. Computers, through tone mapping, can easily do this. Even HDMI can transmit XYZ colours natively.
Light123, can you tell us what brand the lasers are in the Sony Pico model you took apart? I'm curious about their peak modulation bandwidth.
The highest analog modulation frequency I've found for lasers on the pro market (for lithography and similar applications) is about 300 Mhz. But they are not cheap. So that's why I wonder what lasers and laser drivers the Sony uses.
Apparently they are in the 5mw - 50mw power range according to Karl Guttag (say what you want about him but his teardown is quite interesting. There's another site that took apart the Sony too, did someone post that one here? It's on AVS).
So long as they don't overlap you are golden. Many DLP projectors use yellow / magenta / cyan / other primaries in their colour wheels for this purpose, but of course they lose brightness because that cuts out the duty cycle of light for the other colours.
However for simultaneous lasers that is not a problem, your white brightness is the same as your colour brightness and then you can emulate every possible permutation of wavelengths and intensities at each of those, if you can cover the entire visible frequency spectrum with individually modulated lasers and the appropriate mixing / modulation logic.
This is why I suggested using a 16 bit float ACES or XYZ color input because that would be translatable to theoretically any visible colour, even far beyond rec 2020. Computers, through tone mapping, can easily do this. Even HDMI can transmit XYZ colours natively.
Light123, can you tell us what brand the lasers are in the Sony Pico model you took apart? I'm curious about their peak modulation bandwidth.
The highest analog modulation frequency I've found for lasers on the pro market (for lithography and similar applications) is about 300 Mhz. But they are not cheap. So that's why I wonder what lasers and laser drivers the Sony uses.
Apparently they are in the 5mw - 50mw power range according to Karl Guttag (say what you want about him but his teardown is quite interesting. There's another site that took apart the Sony too, did someone post that one here? It's on AVS).
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Re: Laser projectors general? [zero lag & zero blur!!!]
Some references on Laser and Metamerism issues,
http://www.cis.rit.edu/~yxa8513/Publica ... IC2014.pdf
http://www.displaydaily.com/2014-10-06- ... projection
https://cias.rit.edu/media/uploads/facu ... merism.pdf
Sounds like dual set of RGB primaries is the way to go for a practical solution, optimized such that the pair of each primary minimizes the metamerism problem. I'd rather drop to a smaller gamut to avoid viewer variation in perceived color, and to get more perceived brightness to increase contrast ratio.
http://www.cis.rit.edu/~yxa8513/Publica ... IC2014.pdf
http://www.displaydaily.com/2014-10-06- ... projection
https://cias.rit.edu/media/uploads/facu ... merism.pdf
Sounds like dual set of RGB primaries is the way to go for a practical solution, optimized such that the pair of each primary minimizes the metamerism problem. I'd rather drop to a smaller gamut to avoid viewer variation in perceived color, and to get more perceived brightness to increase contrast ratio.
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- Joined: 06 Apr 2015, 16:09
Re: Laser projectors general? [zero lag & zero blur!!!]
Terrific links, very informative.
The factors contributing to contrast ratio involved in the second link pertain more to commercial cinema than home theater, since at least in home theater you can increase the room contrast quite easily and cheaply by using black velvet material:
http://projectiondream.com/en/contrast- ... vironment/
Also, the "veiling contrast" from the lens aberrations and dispersion don't apply to lensless projectors such as direct laser raster displays such as the ones we're discussing here, so potentially having a 1M : 1 native / static contrast ratio could be a decent boost from a 100,000:1 one in the final CR measurement that includes everything including the light bounce / light pollution from the theater back onto the screen. One of the biggest and cheapest upgrades to a home theater, even for super cheap projectors, is making the room blacker. Then of course you always want a better contrast ratio in the projector and better quality lenses if not no lenses at all. Lenses are the enemy to reach that last mile.
Then, once that's done, you can even use a black screen to go that extra step, or if you want to be able to watch with some lights on. Then again, a dimmer is the cheapest thing, you dim more and get greater CR, cheapest CR boost in the world. Plenty of threads on AVS about people making their own black screens and even some high end laser projectors from LG and Sony use black screens so that you can watch it during the day without it being totally washed out.
The factors contributing to contrast ratio involved in the second link pertain more to commercial cinema than home theater, since at least in home theater you can increase the room contrast quite easily and cheaply by using black velvet material:
http://projectiondream.com/en/contrast- ... vironment/
Also, the "veiling contrast" from the lens aberrations and dispersion don't apply to lensless projectors such as direct laser raster displays such as the ones we're discussing here, so potentially having a 1M : 1 native / static contrast ratio could be a decent boost from a 100,000:1 one in the final CR measurement that includes everything including the light bounce / light pollution from the theater back onto the screen. One of the biggest and cheapest upgrades to a home theater, even for super cheap projectors, is making the room blacker. Then of course you always want a better contrast ratio in the projector and better quality lenses if not no lenses at all. Lenses are the enemy to reach that last mile.
Then, once that's done, you can even use a black screen to go that extra step, or if you want to be able to watch with some lights on. Then again, a dimmer is the cheapest thing, you dim more and get greater CR, cheapest CR boost in the world. Plenty of threads on AVS about people making their own black screens and even some high end laser projectors from LG and Sony use black screens so that you can watch it during the day without it being totally washed out.
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Re: Laser projectors general? [zero lag & zero blur!!!]
Speaking of laser projectors, projection dream has a review of an expensive laser-illuminated one:
http://projectiondream.com/en/epson-eh- ... or-review/
http://projectiondream.com/en/epson-eh- ... or-review/
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Re: Laser projectors general? [zero lag & zero blur!!!]
HAHAHAHAAH!!! Lol
Re: Laser projectors general? [zero lag & zero blur!!!]
Are you guys ready?
Big announcement coming!
Stay tuned to this thread...
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Re: Laser projectors general? [zero lag & zero blur!!!]
Can you please include pictures of your actual hardware when you make this announcement?
Re: Laser projectors general? [zero lag & zero blur!!!]
spacediver wrote:Can you please include pictures of your actual hardware when you make this announcement?