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piratepowwow
Joined: 27 May 2010
Posts: 51
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| Posted: Wed Jun 23, 2010 4:35 pm Post subject: |
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Hmmmmmmmmmmmmmmmmmm
1080P at 120hz...I don't know if there are any CRT projectors that can handle that kind of bandwidth reasonably.
The best projector on the list is the Cine9 and it only has a bandwidth of 180mhz. 1080P60 uses about 187mhz. The Cine9 has slightly less bandwidth than 1080P60 uses; it's going to be rather soft at 120hz.
Of course our projectors will display content well beyond the projector's bandwidth capabilities, but you lose detail and color.
To get the FULL 3D experience you will need 4 projectors, each displaying 60hz.
Two projectors per side of an edge blended setup. Seeing as the bandwidth for 1080P120 is somewhere around 373mhz, and about a 20% overlap will be used, the total bandwidth comes out to around 448mhz. Divide this by 4 projectors and each one has to cover only 112mhz, easily done.
Do this, and you will acheive immortality.
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David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
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| Posted: Wed Jun 23, 2010 6:04 pm Post subject: |
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The bandwidth is always half the pixel clock as a single pixel can't provide a full period. Unless you want to factor in a razor sharp transition between pixels.
I find talk of bandwidth rather pointless in reality as numbers won't relate to what you see on screen anyway.
And when you talk real content all bandwidth goes out the window anyway.
Many other factors come in when displaying content at high resolution.
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SNR of people are ridiculously low.
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piratepowwow
Joined: 27 May 2010
Posts: 51
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| Posted: Wed Jun 23, 2010 6:30 pm Post subject: |
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David,
For bandwidth calculation I used Extron's guide here: http://www.extron.com/company/article.aspx?id=vidband3
"The bandwidth rule of thumb states that a piece of video gear must have a bandwidth specification of 2 to 3 times the frequency of the original video signal. "
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David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
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| Posted: Wed Jun 23, 2010 6:56 pm Post subject: |
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That is for gear stacked on top of each other that should not degrade the signal.
-3dB is way better than the "sharpness" of the dot being painted anyway so you will waste a lot of bandwidth that could have gone to added content instead of "defining" an edge.
Each to there own I guess.
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SNR of people are ridiculously low.
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Spanky Ham
Joined: 22 Mar 2006
Posts: 5643
Location: Comedy Central
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| Posted: Thu Jun 24, 2010 5:08 am Post subject: |
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| piratepowwow wrote: | David,
For bandwidth calculation I used Extron's guide here: http://www.extron.com/company/article.aspx?id=vidband3
"The bandwidth rule of thumb states that a piece of video gear must have a bandwidth specification of 2 to 3 times the frequency of the original video signal. " |
I think Extron's bandwidth calculator has become standard thinking, but unfortunately it has created a lot of confusion and misinformation.
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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| Posted: Thu Jun 24, 2010 5:44 pm Post subject: |
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| piratepowwow wrote: | David,
For bandwidth calculation I used Extron's guide here: http://www.extron.com/company/article.aspx?id=vidband3
"The bandwidth rule of thumb states that a piece of video gear must have a bandwidth specification of 2 to 3 times the frequency of the original video signal. " |
That's for switching devices in a signal chain where you need to minimize the losses that would otherwise accumulate to intolerable values too quickly. It is not required for the last device in a chain (the display) to maintain that very high standard. The factor used for display devices should be about 1.5 to 2.
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SYC
Joined: 16 May 2006
Posts: 269
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| Posted: Sat Nov 20, 2010 10:26 pm Post subject: |
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The shutter glasses decrease so much light, so is the light output of CRT enought for 3D? I have an ceiling-mounted 8" and a 80-inch wide, gain one screen . I am afraid that if I go 3D way and finally find the picture is too dim. If it is a solution to change a high-gain screen for 3D?
SYC
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