and there i thought a crt could never produce an exact square wave (without some rise and fall time no matter how tweaked) so 100% resolving 1080p is never the case let alone resolving it with the limitations optically and a perfect astig.
You were correct - No crt (or anything else for that matter) will ever be able to produce a perfect square wave. In the case of a crt, it doesn't matter, as it doesn't need to.It never receives a square wave.
Please excuse any errors as it has been over 40 years, but a Fourier Transformation of a step response show that it is the infinite sum of all frequencies from zero to infinity. Infinite bandwidth would be required!
When a crt projector is rated as having a bandwidth of 150Mhz, unless they are cheating, that means that the signal at that frequency is 3db less than the input signal is. That means it is 1/2 the voltage it should be. It initially falls off from there at 6db per octave and then gets much steeper as the different stages of the video chain have additional effects.
I wish I could have found the patterns that Craig posted a while back as it showed this effect very well.
That is one of the reasons why blending looks so good as the the bandwidth requirement is cut nearly in half (less the blend percentage).
This, of course, has completely ignored any physical limitations and only dealt with the video electrical signal.
Link Posted: Wed May 30, 2012 11:35 am Post subject:
To put some numbers to this and for simplicity ignoring the increase necessary by creating porches, a 1920X1080@72Hz signal is about 150Mhz. To create the same final 1920X1080@72Hz in a blend, each projector only receives an 82.7Mhz signal. Any drop off from limitations is for all practical purposes, a non-issue. If you decide to up the resolution or refresh rate past 1920X1080@72, you will of course use up some of this advantage. To up the resolution/refresh with a single projector would almost be impossible without serious anomalies.
BTW, the "physical" issues at this rate are also reduced by blending.
Link Posted: Wed May 30, 2012 12:27 pm Post subject:
VideoGrabber wrote:
> I run 1200 lines (800 from my DVDO VP50 and then scale to 1200 with my blend boxes). If I had a pair of 9" projectors, I would take it to 1600. <
Thanks again, Bob. You're basically doing what I would expect, and would do myself. Makes good sense. I have no problem accepting 1200p on 8" PJs (~90 kHz scanrate), or 1600p on 9-inchers. I appreciate the clarification.
let's look at this, and this is so common from folk who first has not really experienced the better high end blend setups, because even the thought of changing native 1920X1080 to any other resolution than its true nature (1920X1080) before going into the blend processor means a serious loss in performance. This need not be tried out, because once the native resolution was converted to 800 lines, in the real blend world, it would no longer be considered an High Def signal.
Consumer and for the most part HD source resolutions should remain untouched, with the exception of deinterlacing 1080I to 1080P, which maintains the same line of resolution. The only other thing that can happen without effecting the resolution is changing the refresh rate. So going from 60hz to 72Hz, etc still maintains that same resolution structure, which is the actual nature of the signal.
Another reason to respect this is to maintain true 1:1 before the blend process. Any source into a blend unit that is not native (1920X1080 - 1280X720, etc) and true 1:1 when dealing the HD signals creates a lower performance image going into the projectors.
A good blend unit should always get true and native HD on its input. Scaling should never be used when dealing with HD signals, and is not necessary with any of the blend units I know of. Again, scaling degrades the true nature of the HD signal, and it should never be done BEFORE the blend process.
Not familiar wit the "blend boxes" mentioned, but I would doubt very seriously if they have the power of some of the units that I'm familiar with, that clearly follow the Industries rule to respect the input and output resolutions to process HD signals.
So using a scaler before the blend box to scale an HD signal makes absolutely no sense, when the native signal MUST go into the blend unit.
The blend unit must maintain that 1:1 mapping, so what it does is split the signal into two 4:3 images. And it does so by also allowing for 256 to 380 pixel blend zone (20% to 25%). The blended image MUST maintain a 1:1 mapping, so that would mean it should put out one of the standard resolutions like:
1280X1024
1400x1050
1600-1200
There are more, but these are the recommended rates that should be used for the projectors we deal with, because they all are 1:1 - 4:3 ratio.
That is one of the reasons why blending looks so good as the the bandwidth requirement is cut nearly in half (less the blend percentage).
This, of course, has completely ignored any physical limitations and only dealt with the video electrical signal.
Bob
Ok, but I'm not sure why you keep saying the bandwidth would be half of the bandwidth, and I would agree, but for a high performance HD source to be properly displayed, bandwidth would not be as low as you think.
If haven't noticed, the entire industry is moving to higher resolutions. And there's reason for that, mainly because of the increase in signal source quality itself, it makes it better to go with higher resolutions without seeing any real loses. But still, the reasonable and standard rates should work well for us and our low resolution projectors:
1280X1024
1400x1050
1600-1200
Let's look at the three scan rates (above) and attach the bandwidth requirements to them:
For the sake of argument, I'll use the AMX bandwidth calculator, that instead of -3db, it uses the +/- 3db figure. So its more closer to a flat bandwidth response.
Now, if a CRT projector is operating from any of the three recommended scan rates as suggested by the industry, where would there be a less than or half of the required bandwidth needed?
But back to your 1200P resolution you mentioned, what horizontal resolution you also use?
Link Posted: Wed May 30, 2012 1:03 pm Post subject:
I see why you're confused, Mike... They're cropping (not scaling) 1080p to arrive at 800p or 832p or whatever, so there is no resolution loss or scaling (of scope material), and the content is still 1:1 mapped, and "HD" even if the signal isn't "standard" anymore.
I don't know why you're suggesting anybody needs to use those "standard" resolutions either, Mike. The 1280x1024 resolution you mentioned is the old standard graphics workstation resolution, but it isn't even 4:3, and has little relevance in HT with modern resolutions. 1600x1200 is at least 4:3, but still has no relevance for home theater. Same with 1400x1050... No reason to even consider it.
Bandwidth? Yeah, using your "standard" resolutions, you only drop about 40% of the bandwidth requirement, but using Bob and Nash's effective and technically correct method, you truly are closer to 50%.
What the big commercial guys were doing 5-10 years ago just doesn't have much relevance today with scope screens and BD as the source.
Link Posted: Wed May 30, 2012 1:35 pm Post subject:
Quote:
This need not be tried out, because once the native resolution was converted to 800 lines, in the real blend world, it would no longer be considered an High Def signal.
It was never converted!!! The process has been named "active area scanning" All it does is ignore the lines utilized to make black on the top and bottom of the picture because of the difference in aspect ratios of the BD and the actual picture - NO CHANGE TAKES PLACE! The only change is that we are saving about 1/3 of wasted bandwidth.
If you don't consider it to be HD, that is your choice, but you are then saying that every 2.4 movie on BD is no longer High Def.
Quote:
So using a scaler before the blend box to scale an HD signal makes absolutely no sense, when the native signal MUST go into the blend unit.
There is no scaling that takes place before blending!!!!!!! It is native!!!
Quote:
Ok, but I'm not sure why you keep saying the bandwidth would be half of the bandwidth, and I would agree, but for a high performance HD source to be properly displayed, bandwidth would not be as low as you think.
Ok - Obviously you have figured out a way to ignore the simple laws of physics but have not revealed your secret.
Quote:
The blended image MUST maintain a 1:1 mapping, so that would mean it should put out one of the standard resolutions like:
1280X1024
1400x1050
1600-1200
Incredible! How can you start with 1920X1080 and end up with any of the list you gave and claim to be 1:1. Unbelievable! The ONLY reason that this list is called "standard" is because they are the normal resolutions used by computers and also the digital projectors native resolutions! Analog projectors are not stuck with fixed pixels.
Quote:
There are more, but these are the recommended rates that should be used for the projectors we deal with, because they all are 1:1 - 4:3 ratio
Yes - But they are not the resolutions that are on BD's or any other consumer source! Displaying them does not add any resolution - It create's artifacts!
I have three final resolutions that I use: 1920X1080@60Hz, 1920X800@72 and 1920X1200@72. Of these three, only the last one uses any scaling at all, and as I have stated it is a 1.5 ratio and therefore an easy conversion that is done by the Blender!
The 1064 horizontal resolution that each projector displays is NOT the result of scaling, but the result of zooming in on that many pixels from each side and ignoring the rest - It is truly 1:1 the whole way!
Mike, I give up. Unless you have a halfway intelligent comment or question, I will not respond.
My concern is that there might be some viewers that are considering blending with their crt's and you are going to confuse them with gross misinformation. That would be a shame as this wonderful forum provides a wealth of information to so many.
Link Posted: Wed May 30, 2012 1:42 pm Post subject:
ecrabb wrote:
I see why you're confused, Mike... They're cropping (not scaling) 1080p to arrive at 800p or 832p or whatever, so there is no resolution loss or scaling (of scope material), and the content is still 1:1 mapped, and "HD" even if the signal isn't "standard" anymore.
I don't know why you're suggesting anybody needs to use those "standard" resolutions either, Mike. The 1280x1024 resolution you mentioned is the old standard graphics workstation resolution, but it isn't even 4:3, and has little relevance in HT with modern resolutions. 1600x1200 is at least 4:3, but still has no relevance for home theater. Same with 1400x1050... No reason to even consider it.
Bandwidth? Yeah, using your "standard" resolutions, you only drop about 40% of the bandwidth requirement, but using Bob and Nash's effective and technically correct method, you truly are closer to 50%.
What the big commercial guys were doing 5-10 years ago just doesn't have much relevance today with scope screens and BD as the source.
SC
The very newest systems still have those same resolutions in them for the 'older' projectors, that we still use. But things have changed with analog still being limited in bandwidth to 165mhz, with DVI going as high as 330mhz. So the only thing that has changed is the higher scan rates, and them being on DVI.
I did not read the entire post, but reading 800 lines into the blend boxes coming out of the VP 50 lead me to believe it was scaling down the image. Nothing mentioned cropping, which I'm shocked that's not being done in the blend units. Where I think it would make more sense because, even the very latest blend units do everything in the unit itself, which still makes for why we are STILL making sure the native rate is going into the blend processor. And in when that's not done especially on a 3D setup, there text in the image distorts. In fact we have a system we're discussing now that has that problem.
Yes, the industry has changed over the years, but for CRT, nothing has changed with the newer processors. Those same old scan rates are still in them. And they still have the predetermined rates.
An for some reason 1600X1200P is still thought of as a lower bandwidth, when its pretty much the same bandwidth as 1920X1080P
However, there is a newer standard, or resolution that was later found to be the best, and that is 1440X1080P. They have found that going 1440X1080P produces the best image. And the reason has more to do with maintain the vertical resolution.
Link Posted: Wed May 30, 2012 1:53 pm Post subject:
Boilermaker wrote:
There is no scaling that takes place before blending!!!!!!! It is native!!!
Ok, I did not read the entire thread, so I did not see why you were using the VP 50 and for what.
Quote:
Incredible! How can you start with 1920X1080 and end up with any of the list you gave and claim to be 1:1. Unbelievable! The ONLY reason that this list is called "standard" is because they are the normal resolutions used by computers and also the digital projectors native resolutions! Analog projectors are not stuck with fixed pixels
They are actually still being used today for 4:3 aspect ratios, and yes, analog projectors are not fixed pixel, but the resolutions are for the standards 4:3 CRT.
Quote:
I have three final resolutions that I use: 1920X1080@60Hz, 1920X800@72 and 1920X1200@72. Of these three, only the last one uses any scaling at all, and as I have stated it is a 1.5 ratio and therefore an easy conversion that is done by the Blender!
The 1064 horizontal resolution that each projector displays is NOT the result of scaling, but the result of zooming in on that many pixels from each side and ignoring the rest - It is truly 1:1 the whole way!
Ok, so please explain how either of those three scan rates are not putting a strain on your projector?
Mike, I give up. Unless you have a halfway intelligent comment or question, I will not respond.
My concern is that there might be some viewers that are considering blending with their crt's and you are going to confuse them with gross misinformation. That would be a shame as this wonderful forum provides a wealth of information to so many.
[/quote]
No, and to be honest with you. I think anyone interested in doing blending should go with a blend unit that does most things in the unit itself. Any modern blend unit today should have everything done in the unit. I know that's the case with the Gforce cards.
Link Posted: Wed May 30, 2012 1:59 pm Post subject:
And lastly, prove your point by posting a screenshot of the pixel bandwidth test (one pixel one, one off) test.
And do so at the three resolutions you mentioned. I would love to see those NEC's resolved that pattern. For some reason, you're not going to post it. But if you did, it would move you away from theory and allow you to prove your point..
Joined: 12 Jan 2007 Posts: 12843 Location: West Seneca NY
TV/Projector: Marquee 8000, 8500 And a 9500LC RetroIV , 2 Longbow 8500 Ultras(2004!!)Hd145's , Ampro 3600, a G90!!
Link Posted: Wed May 30, 2012 2:11 pm Post subject:
Mike the Tv-Ones will do 1:1 pixel mapping, I have screen shot showing the 1:1 but i'll let you go find them.
Blending just zoom's the entire image. 1920x1080 is the same if its a 1 inch screen or a 2000 foot screen!! No matter what refresh rate!!
I higher refresh rate doesn't increase resolution!!!!
Have you seen the TV-One units Mike? Go to Bobs Place and see for your self.
I have done all sorts of resolutions and the 1:1 pixel works out perfectly each time. Also i run my blend at 96hz, i like to hide the scan lines and smooth out the image a bit. And it looks f*cking awesome beside the blend zone the lowest IRE's. But I'll work on that when I get time.
Nashou _________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"The government can't control the economy without controlling the people" RR
One Smart Dog!!! Tom Bauerle to Andre Cuomo" Elliot Spitzer Screwed some Prostitutes, you screwed the Constitution" On his call to Cuomo to Resign!!!
Link Posted: Wed May 30, 2012 2:31 pm Post subject:
Nashou66 wrote:
Mike the Tv-Ones will do 1:1 pixel mapping, I have screen shot showing the 1:1 but i'll let you go find them.
Blending just zoom's the entire image. 1920x1080 is the same if its a 1 inch screen or a 2000 foot screen!! No matter what refresh rate!!
I higher refresh rate doesn't increase resolution!!!!
Have you seen the TV-One units Mike? Go to Bobs Place and see for your self.
I have done all sorts of resolutions and the 1:1 pixel works out perfectly each time. Also i run my blend at 96hz, i like to hide the scan lines and smooth out the image a bit. And it looks f*cking awesome beside the blend zone the lowest IRE's. But I'll work on that when I get time.
Nashou
I want to see Bob post the shot. And I would like to see it posted at resolutions he mentioned. Not sure how you guys keep saying the low bandwidth things, and you're able to say that even at 96hz....I know, I'm missing something.
Anyway, I was able to make it out to Barco Training class and got to see all the new stuff, especially the New D-Cinema stuff. And so that you'll know, both Barco and Christie have seriously geared themselves towards Digital Cinema. With the exception of how they secure the movie content and that the methods they use to protect it, they still stick to the basics of HD. but they call it 2K (2048X1080P) which will be a standard for a long time to come.
Well of course, I got my cup as well with their very latest sayings!
Link Posted: Wed May 30, 2012 2:34 pm Post subject:
[quote="mp20748"]
Boilermaker wrote:
Quote:
I have three final resolutions that I use: 1920X1080@60Hz, 1920X800@72 and 1920X1200@72. Of these three, only the last one uses any scaling at all, and as I have stated it is a 1.5 ratio and therefore an easy conversion that is done by the Blender!
The 1064 horizontal resolution that each projector displays is NOT the result of scaling, but the result of zooming in on that many pixels from each side and ignoring the rest - It is truly 1:1 the whole way!
Ok, so please explain how either of those three scan rates are not putting a strain on your projector?
He sends 1064 x 1080 to each PJ for 1.78AR material or 1064 x 800 for 2.40AR material. The combined image resolves 1920 x 1080 or 1920 x 800.
Each PJ has less strain because it's effectively doing half the job. The challenge with blending is not 1:1 it's getting the blend zone to be as seemless as possible _________________ Projector: 9500LC- Dragan's HD Mods, ETECH PS Mods, Moome 1.3, HD10F's & a V1 case!
Joined: 12 Jan 2007 Posts: 12843 Location: West Seneca NY
TV/Projector: Marquee 8000, 8500 And a 9500LC RetroIV , 2 Longbow 8500 Ultras(2004!!)Hd145's , Ampro 3600, a G90!!
Link Posted: Wed May 30, 2012 2:55 pm Post subject:
[quote="jbmeyer13"]
mp20748 wrote:
Boilermaker wrote:
Quote:
I have three final resolutions that I use: 1920X1080@60Hz, 1920X800@72 and 1920X1200@72. Of these three, only the last one uses any scaling at all, and as I have stated it is a 1.5 ratio and therefore an easy conversion that is done by the Blender!
The 1064 horizontal resolution that each projector displays is NOT the result of scaling, but the result of zooming in on that many pixels from each side and ignoring the rest - It is truly 1:1 the whole way!
Ok, so please explain how either of those three scan rates are not putting a strain on your projector?
He sends 1064 x 1080 to each PJ for 1.78AR material or 1064 x 800 for 2.40AR material. The combined image resolves 1920 x 1080 or 1920 x 800.
Each PJ has less strain because it's effectively doing half the job. The challenge with blending is not 1:1 it's getting the blend zone to be as seemless as possible
Exactly
Nashou _________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"The government can't control the economy without controlling the people" RR
One Smart Dog!!! Tom Bauerle to Andre Cuomo" Elliot Spitzer Screwed some Prostitutes, you screwed the Constitution" On his call to Cuomo to Resign!!!
Link Posted: Wed May 30, 2012 3:17 pm Post subject:
[quote="Nashou66"]
jbmeyer13 wrote:
mp20748 wrote:
Boilermaker wrote:
Quote:
I have three final resolutions that I use: 1920X1080@60Hz, 1920X800@72 and 1920X1200@72. Of these three, only the last one uses any scaling at all, and as I have stated it is a 1.5 ratio and therefore an easy conversion that is done by the Blender!
The 1064 horizontal resolution that each projector displays is NOT the result of scaling, but the result of zooming in on that many pixels from each side and ignoring the rest - It is truly 1:1 the whole way!
Ok, so please explain how either of those three scan rates are not putting a strain on your projector?
He sends 1064 x 1080 to each PJ for 1.78AR material or 1064 x 800 for 2.40AR material. The combined image resolves 1920 x 1080 or 1920 x 800.
Each PJ has less strain because it's effectively doing half the job. The challenge with blending is not 1:1 it's getting the blend zone to be as seemless as possible
Exactly
Nashou
And I agree...but, I would like to also see those screenshots showing that those resolution are being resolved, and to be honest with you, that would be the determiner on this matter.
Oh, I'm very aware of when everything is done right down to the math, but there's something that just does not look right.
For instance, a blended setup should rendered the brightness and sharpness of a good quality Lcos digital. And should even display good to better background detail. But in order for that to happen, some things would need to take place first.
And even on my single 9500LC, I can get it to resolve all those rates that was mentioned, and can get it to do a better resolve and sharpness job than either blend setup. And it will also resolve the patterns to backup what I'm saying.
So since there is so much benefit mentioned from owning a blend setup and that some may want to do the same, then show us something that would make us want to blend rather than keep saying how good it looks.
One of the main benefits of having blended CRT's is 1, brightness. 2, the ability to clearly project higher resolutions, 3, a punchier and more dynamic image.
Come on guys, prove me wrong by posting those shots..
Joined: 12 Jan 2007 Posts: 12843 Location: West Seneca NY
TV/Projector: Marquee 8000, 8500 And a 9500LC RetroIV , 2 Longbow 8500 Ultras(2004!!)Hd145's , Ampro 3600, a G90!!
Link Posted: Wed May 30, 2012 3:28 pm Post subject:
mp20748 wrote:
And I agree...but, I would like to also see those screenshots showing that those resolution are being resolved, and to be honest with you, that would be the determiner on this matter.
Oh, I'm very aware of when everything is done right down to the math, but there's something that just does not look right.
For instance, a blended setup should rendered the brightness and sharpness of a good quality Lcos digital. And should even display good to better background detail. But in order for that to happen, some things would need to take place first.
And even on my single 9500LC, I can get it to resolve all those rates that was mentioned, and can get it to do a better resolve and sharpness job than either blend setup. And it will also resolve the patterns to backup what I'm saying.
So since there is so much benefit mentioned from owning a blend setup and that some may want to do the same, then show us something that would make us want to blend rather than keep saying how good it looks.
One of the main benefits of having blended CRT's is 1, brightness. 2, the ability to clearly project higher resolutions, 3, a punchier and more dynamic image.
Come on guys, prove me wrong by posting those shots..
It just fun..
Wait which one is it? It can or can't? make up your mind.
Here read this Mike, its on Active Area Scanning. It will explain the 1920x800p@72hz for you.
Link Posted: Wed May 30, 2012 3:41 pm Post subject:
mp20748 wrote:
And even on my single 9500LC, I can get it to resolve all those rates that was mentioned, and can get it to do a better resolve and sharpness job than either blend setup. And it will also resolve the patterns to backup what I'm saying.
So since there is so much benefit mentioned from owning a blend setup and that some may want to do the same, then show us something that would make us want to blend rather than keep saying how good it looks.
One of the main benefits of having blended CRT's is 1, brightness. 2, the ability to clearly project higher resolutions, 3, a punchier and more dynamic image.
Come on guys, prove me wrong by posting those shots..
It just fun..
Okay, so it sounds like the issue isn't whether when you blend you can resolve 1:1; it's whether Nash's or Bob's projectors can do 1:1 at all. So it's a Bob/Nash PJ vs the all mighty Super MP 9500LC
Nash already posted a screen shot of his PJ resolving 1:1 so I'm not sure why we keep going around in circles on this _________________ Projector: 9500LC- Dragan's HD Mods, ETECH PS Mods, Moome 1.3, HD10F's & a V1 case!
Ok that last pic is before i realized i need to play with the peaking circuit, so that is why the top box colors are off. Actually its in both pics. Thats from 2010. I still had shceimphlug to do in the blend zone( Still havn't got that done yet )
Athanasios _________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"The government can't control the economy without controlling the people" RR
One Smart Dog!!! Tom Bauerle to Andre Cuomo" Elliot Spitzer Screwed some Prostitutes, you screwed the Constitution" On his call to Cuomo to Resign!!!
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