Why does the kd34xbr960 need 1400 line of resolution. - Page 4 - AVS Forum
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post #91 of 306 Old 11-16-2004, 07:26 PM
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Quote:
Originally posted by Artwood
If Sony is able to achieve 1400 in 34-inch Widescreen and 36-inch 4:3, do you think they would have the technical expertise to boldly go where no one has gone before and dream the impossible dream and do the same 1400 in a larger size set? I'm sorry for being ridiciulous. Everyone knows that might decrease sales of 42-inch Rear Projection LCD. Making money is always more important than Picture Quality!
It you will research a bit on the way a CRT functions you will find that they are and have been running into real physical limitations to the CRT for years. Gun speed is a big problem. Yoke deflection is another. Drawing an image on a relatively flat large screen is filled with inherent hurdles. Not to mention the weight of such a finished product. 350lb 42" CRT anyone?

If you like CRT displays and want larger look to plasmas now as a compromise and SED in the future. SED solves all the CRTs inherent problems if they can figure a way to reliably create the arc.

ss
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post #92 of 306 Old 11-16-2004, 07:31 PM
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Quote:
Originally posted by BigGreenMat
Alright well this thread has been awfully informative to me the noob as far as the actual physics and such involved in CRT technology. The question I have is why can't a CRT television produce greater resolutions? Haven't CRT PC Monitors been doing as great or great resoultions at >60hz for YEARS now? I mean you can easily get a 17" monitor that can display 1600x1200. According to what you all are stating here is the PC actually only showing at most 1100 lines by 625? This entire thread I constantly thought 'Why can't we have full 1080i resolution on such a large tube' and 'What is with all the problems with conversion'. CRT monitors have been doing these things for a while quite a bit better than any LCD technology. What am I missing here?

Oh and given all the things you have all stated is there any reason then that I should get say a Samsung CRT HDTV over a Samsung CRT EDTV? Is the question only one of what signals they receive or is the actual display different? Will an EDTV actually DISPLAY at 480p? Since HDTVs obviously don't display at 720p or 1080i.
Yes an EDTV will easily pull off 480p. The wider a range in vertical resolution you ask the set to do, the worse will be its performance on one or more of them.

IMO 540p on one of these sets, particulary a dot shadow mask set, would look quite nice. The jury seems to still be out as to whether the Toshiba will do 540p on its latest sets on most input resolutions. If so that would deserve a hard look.

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post #93 of 306 Old 11-16-2004, 07:45 PM - Thread Starter
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SS
Why not just phone or email Toshiba? I'm 95% convinced 540p is not a universally applicable display option. Again, Sebceocanada (I think it was), talks specifically about DVD and non specific about HD sources. I would also point out that Toshiba is even worse than Sony in terms of overstating and exagerating it's feature's. I love there "proprietary" Colorstream technology. That's a "Good One"!!!;)
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post #94 of 306 Old 11-16-2004, 08:23 PM
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Originally posted by gdg
SS
Why not just phone or email Toshiba? I'm 95% convinced 540p is not a universally applicable display option. Again, Sebceocanada (I think it was), talks specifically about DVD and non specific about HD sources. I would also point out that Toshiba is even worse than Sony in terms of overstating and exagerating it's feature's. I love there "proprietary" Colorstream technology. That's a "Good One"!!!;)
Yea they all love the words they can cobble together and then trademark. I will try to call them Thurs, I have a trip tomorrow during business hours.

I am personally leaning towards an ED plasma at this point largely because of my viewing distance. I am getting a set for the bedroom and my viewing distance is now a little over 10'.

ss
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post #95 of 306 Old 11-16-2004, 08:54 PM - Thread Starter
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I guess those network logos don't worry you?:D
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post #96 of 306 Old 11-16-2004, 09:15 PM
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Originally posted by gdg
I guess those network logos don't worry you?:D
It does worry me a little, but allegedly on these newer sets burn-in has been relegated to a temporary annoyance.

At least thats what theyre saying.....

They have extended the lifespan on the glass so that should coincide with a drop in burn-in potential....I hope.

Its gonna be a patch til better things come along I am also hoping. SED really has the potential of being the true CRT repalcement in larger sizes and lower weights and consistent screenwide performance.

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post #97 of 306 Old 11-16-2004, 09:20 PM
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Quote:
Originally posted by subysouth
Whoa not so fast there. Theres only one big problem with that approach.

There isn't just one beam exiting that aperture grill, there are three. One for each red, blue and green phosphor. Unless Sony has been able to figure a way also to cycle the beam current 4200 times per line and use a single gun. The widescreen profile itself makes scanning an aperture pitch grille more challenging.
There are three beams but they all move in tandem at the same time. When I talk about drawing a single vertical red line, only one gun will cycle on and off per scan line, 1080 times each frame. The Blue and Green guns remain silent. The only thing that changes with a widescreen profile is that the beam has to travel a longer distance to illuminate the edges of the screen and this means that the focus will be larger and the projection of the beam on the phosphors will be oval instead of round. That is why the pitch must be larger at the edges than in the center, but that just means that the wires that are strung vertically to form the grill are spaced a little more apart on the edges.


Quote:
Originally posted by subysouth
So now you have to figure a way that Sony can have a .45-61mm horizontal pitch and a .39mm average vertical stripe pitch(will be shorter in the center) and the horizontal has to comprise three distinct addressable phosphors arranged horizontally being addressed by three separate guns with in theory three round beam spots. And no bleed or overlap.

Much taller order than 1400 lines horizontally. I don't share your assumption of 1080i without overlap. I think thats why you see a full picture at 1080i instead of scan lines as gdg noted. And it only has to muddy in one direction to muddy both directions.
ss
I agree that if it's going to muddy in one direction then its going to muddy in the other direction as well. And there is probably overlap because the beam diameter may actually be be fatter to allow the horizontal lines to all blend together when displaying 480p. Doing 1080i with this same beam means that the lines of alternate frames will definitely overlap the lines of the previous frames, but because of the decay of the phosphors, the eye tends to pick up 1080 lines of distinct visual information.

If I reword the question that the original poster asked:
Once you have optimized the diameter of a round shaped beam so that all 1080 horizontal lines can be scanned with minimum overlap, do you really need a horizontal pitch that is finer than the vertical thickness of the horizontal lines?

My answer would be no unless there is a way to create an electron beam which has a greater height than width. Does anyone know if the grid of the gun can allow the shape the beam to be "sculpted" ?
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post #98 of 306 Old 11-16-2004, 09:34 PM
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Quote:
Originally posted by BigGreenMat
The question I have is why can't a CRT television produce greater resolutions? Haven't CRT PC Monitors been doing as great or great resolutions at >60hz for YEARS now? I mean you can easily get a 17" monitor that can display 1600x1200. What am I missing here?
The problem is that as resolution increases by making the holes in the mask smaller and closer together or by making an aperture grill with more vertical wires, the electron beams end up spending more time colliding with the mask and there are less electrons that hit the phosphors. The result is a screen that looks great from one foot away like a PC monitor but looks very dim when viewed from 6 feet back. That is why there is a balance struck between light output and detail, bearing in mind that when viewers are placed at a comfortable distance, there is a limit as to how much detail they can see.
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post #99 of 306 Old 11-16-2004, 10:29 PM
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Quote:
Originally posted by montreal
There are three beams but they all move in tandem at the same time. When I talk about drawing a single vertical red line, only one gun will cycle on and off per scan line, 1080 times each frame. The Blue and Green guns remain silent. The only thing that changes with a widescreen profile is that the beam has to travel a longer distance to illuminate the edges of the screen and this means that the focus will be larger and the projection of the beam on the phosphors will be oval instead of round. That is why the pitch must be larger at the edges than in the center, but that just means that the wires that are strung vertically to form the grill are spaced a little more apart on the edges.




I agree that if it's going to muddy in one direction then its going to muddy in the other direction as well. And there is probably overlap because the beam diameter may actually be be fatter to allow the horizontal lines to all blend together when displaying 480p. Doing 1080i with this same beam means that the lines of alternate frames will definitely overlap the lines of the previous frames, but because of the decay of the phosphors, the eye tends to pick up 1080 lines of distinct visual information.

If I reword the question that the original poster asked:
Once you have optimized the diameter of a round shaped beam so that all 1080 horizontal lines can be scanned with minimum overlap, do you really need a horizontal pitch that is finer than the vertical thickness of the horizontal lines?

My answer would be no unless there is a way to create an electron beam which has a greater height than width. Does anyone know if the grid of the gun can allow the shape the beam to be "sculpted" ?
They move together as a horizontally aligned trio of theoretically round beams. Like this OOO (which is basically what the Trinitron sets look like with associated sizable gaps between lines to maintain squareness.) It would need to look like this llll to squeeze that many pixels on the set and have 480p be viewable at all. Maybe sculpting the three beams like that is possible but any changes in power are going to amplify changes in vertical bleed.

You did hit on a key point I do agree with. The beam spot is likely oversized to reduce gaps on 480p, so the likelihood is you are already getting some overlap at a line count well short of 1080.

The more I have been pondering this the more I have realized a couple of things. Only on the Sony or another aperature grille equipped set would we even be having this discussion. The aperature due to its theoretically unlimited vertical reolution and horizontally aligned phosphors is uniquely equipped to have an argument's stab at HD and I see why Sony et al lobbied for softness on the horizontal HD resolution first. The comment that bothered me that you made in the other thread montreal was all the current HD monitors are supporting a 1080 vertical line count. Only the Sony and other aperature grille sets might do 1080. Theres no negotiating vertical resolution on a dot mask set, it either is or isnt and the ill effects of lower line counts on those sets would be amplified compared to an aperature grille set in some ways. Meaning they dont bleed anywhere near as much as the aperature grille types and 480p vs 1080i if they were doing it would be immediately and painfully obvious on the same set. I can think of some ways Sony or other aperature grille sets could work it back and forth to get average performance on both ends.

It has sparked a great discussion regardless and made me at least recall and outright learn how these sets actually work.

Im gonna still say that the max resolvable vertical is well below 1080. Where it is I dont know but logic would say Sony should err towards somewhere in the middle of 480 and 1080.

I still think for my viewing pleasure I would prefer a larger dot pitch(with more point control of light output) screen driven progressively to its native resolution. I dont want to be stuck in no mans land on a set trying to do two widely different line counts. And again I question whether the size pixels on this set in particular are useful for the average person and worry about what was done to maintain light output against that smaller pitch/beam spot.

ss
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post #100 of 306 Old 11-16-2004, 11:34 PM
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Quote:
Originally posted by subysouth
I dont share your assumption of 1080i without overlap. I think thats why you see a full picture at 1080i instead of scan lines as gdg noted. And it only has to muddy in one direction to muddy both directions.
Easy enough to test for overlapping scan lines ...

To gdg and anyone else with a Sony Direct View:

As always, properly calibrate using Video Essentials or Avia. Once you have an otherwise well-calibrated set ...

1) Pull up some HD content. A relatively bright, uniform scene will make this easier.
2) Turn Picture setting (aka contrast, aka white level) all the way down.
3) Look very very closely ... you should see very slight gap between scan lines. Hard to see, but they should be there.
4) Now that you know what you're looking for ... slowly start turning Picture back up
5) Stop exactly at the point when the scan lines dissapear
6) Picture setting should be very close to where it started ... whites should appear white ... and the set should be reasonably bright

- If you can't see scan lines in #3, set is most likely out of focus.
- Any Direct View set that achieves #6 has shown some fairly impressive characteristics.

For kicks I did the above on my 34XBR800 ... no overlapping scan lines.
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post #101 of 306 Old 11-16-2004, 11:54 PM
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Quote:
Originally posted by montreal
And there is probably overlap because the beam diameter may actually be be fatter to allow the horizontal lines to all blend together when displaying 480p.
Except that scan lines DON'T blend at 480p or 960i. There's a noticable gap between scan lines when not running at 1080i.

Well, noticeable at 2 ft. ... not noticable at 6 ft.
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post #102 of 306 Old 11-17-2004, 01:00 AM - Thread Starter
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Quote:
Originally posted by subysouth
....and worry about what was done to maintain light output against that smaller pitch/beam spot.

ss
Well, Sony has decided to back up the 960 with a full 2 year warranty. They must have, at least some, faith in the durability of their new technology. I believe that Toshiba's full warranty is only for 1 year.
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post #103 of 306 Old 11-17-2004, 08:34 AM
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Quote:
Originally posted by subysouth
The comment that bothered me that you made in the other thread montreal was all the current HD monitors are supporting a 1080 vertical line count.
What I meant by that is that all these monitors will cause the guns to sweep across the screen 1080 times every thirtieth of a second. Whether you see 1080 distinct lines vertically without too much overlap will depend on how sharp the focus is.

If it is true, as some claim, that the beam focus is sharp enough so that the resulting horizontal lines do indeed have a thickness of about 0.4 mm. (thin enough so that there is actually a slight gap visible between horizontal lines when viewed up close at 480p), then that means that the beam might also allow an average aperture grill pitch of about 0.55 mm. to deliver optimum results.

Again, why would Sony have gone to the trouble to place the phosphor stripes so closely together without improving the sharpness of the electron beams at the same time? When the XBR910 was introduced, I remember reading in the Sony catalog that their MICROFOCUS guns had been included. Formerly, MICROFOCUS guns had only been used on large CRT RPTVs.

In the case of a shadow mask versus an aperture grill and the ability of each to reduce bleeding, one would have to know the physical dimensions of the openings in the metal screening relative to the space between the openings in order to draw any conclusions.
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post #104 of 306 Old 11-17-2004, 12:03 PM - Thread Starter
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Any opinion on whether there is any real advantage in the "megaband" wide band video amplifier, used in the Tosh 34hfx83/84, over the "regular" wideband video amplifier, used in the 34hf83/84?
Or is this, as some have suggested, just a marketing gimmick with no realistically practical advantage.
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post #105 of 306 Old 11-17-2004, 01:12 PM
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Quote:
Originally posted by gdg
Any opinion on whether there is any real advantage in the "megaband" wide band video amplifier, used in the Tosh 34hfx83/84, over the "regular" wideband video amplifier, used in the 34hf83/84?
Or is this, as some have suggested, just a marketing gimmick with no realistically practical advantage.
Having an amplifier that passes higher frequencies is always better even when you don't have a fine pitch mask/grill that can take advantage of this.

The reason is that the amplifier can switch the guns on and off faster (slew rate) provided the input signal has a high frequency content. Switching a gun on faster means that the phosphor elements become fully activated more quickly at the position of transition where we are going from full black to full light. Even if our focus is large and muddy, the transitions are still crisper.

For Sony models, the wider band amplifier is commercially called the HD Detailer and was introduced with the XBR800 to pass up to 30 mhz which is way above what my aperture grill of 850 slots can display.
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post #106 of 306 Old 11-17-2004, 01:53 PM
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Quote:
Originally posted by gdg
Any opinion on whether there is any real advantage in the "megaband" wide band video amplifier, used in the Tosh 34hfx83/84, over the "regular" wideband video amplifier, used in the 34hf83/84?
Or is this, as some have suggested, just a marketing gimmick with no realistically practical advantage.
Unless Toshiba discloses the specification of these "wideband" video amplifiers (was 2003 different from 2004?) who knows. The best test is taking these sets and using test patterns determine if their is a difference in resolution. However at normal viewing distances I doubt you could tell the difference. From what I have read at Keohi HDTV their was a major improvement between 2002 and 2003. In 2002 the video amplifier could not produce a satisfactory resolution on even DVDs. According to them Toshiba redesigned the circuitry for 2003 and it now produces all the resolution a DVD is capable of (and I assume it greatly helped HDTV resolution also).
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post #107 of 306 Old 11-17-2004, 10:13 PM
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Quote:
Originally posted by montreal
What I meant by that is that all these monitors will cause the guns to sweep across the screen 1080 times every thirtieth of a second. Whether you see 1080 distinct lines vertically without too much overlap will depend on how sharp the focus is.

If it is true, as some claim, that the beam focus is sharp enough so that the resulting horizontal lines do indeed have a thickness of about 0.4 mm. (thin enough so that there is actually a slight gap visible between horizontal lines when viewed up close at 480p), then that means that the beam might also allow an average aperture grill pitch of about 0.55 mm. to deliver optimum results.

Again, why would Sony have gone to the trouble to place the phosphor stripes so closely together without improving the sharpness of the electron beams at the same time? When the XBR910 was introduced, I remember reading in the Sony catalog that their MICROFOCUS guns had been included. Formerly, MICROFOCUS guns had only been used on large CRT RPTVs.

In the case of a shadow mask versus an aperture grill and the ability of each to reduce bleeding, one would have to know the physical dimensions of the openings in the metal screening relative to the space between the openings in order to draw any conclusions.
When 1080 lines are laid over the back of a aperature grille screen it is debatable whether all of the lines are discretely displayed. When 1080 lines are a laid across the back of a dot mask screen with 611(an example found in the 1st gen Panny 34") vertical dots, there is no longer a debate. The maximum vertical resolution possible is 611, it may be less but never more.

The aperature grille is a compromise in brightness vs bleed. There is NO vertical delineation of phosphor triad stripes and minimal horizontal. Vertical bleed in a set of this nature is IMO a guarantee. Its almost unavoidable.

On the other hand is much more easy to eliminate bleed entirely on a dot mask set because so much material is dedicated to the mask. The downside is lower brightness given the same general screen size. Dimmer but sharper. You are correct that exact opening vs mask dimensions would firm it up, but especially in the vertical some mask is much more likely to reduce bleed than no mask at all correct?

ss
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post #108 of 306 Old 11-17-2004, 10:19 PM
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Quote:
Originally posted by gdg
Any opinion on whether there is any real advantage in the "megaband" wide band video amplifier, used in the Tosh 34hfx83/84, over the "regular" wideband video amplifier, used in the 34hf83/84?
Or is this, as some have suggested, just a marketing gimmick with no realistically practical advantage.
As others have said, if it works it would be better, but theres little gorunds for actual comparison. Have to just take their word. It wouldnt be a pro or con for me.

The nastiest test pattern to test bandwidth is a square wave single pixel alternate black/white vertical stripe pattern. If it can do this well at the target scan rate it can do anything you need.

I dont think bandwidth is really an issue on these sets. It has already been demonstrated bandwidths can be higher than these sets need to function properly.

ss
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post #109 of 306 Old 11-17-2004, 10:32 PM
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Quote:
Originally posted by dt_dc
Easy enough to test for overlapping scan lines ...

To gdg and anyone else with a Sony Direct View:

As always, properly calibrate using Video Essentials or Avia. Once you have an otherwise well-calibrated set ...

1) Pull up some HD content. A relatively bright, uniform scene will make this easier.
2) Turn Picture setting (aka contrast, aka white level) all the way down.
3) Look very very closely ... you should see very slight gap between scan lines. Hard to see, but they should be there.
4) Now that you know what you're looking for ... slowly start turning Picture back up
5) Stop exactly at the point when the scan lines dissapear
6) Picture setting should be very close to where it started ... whites should appear white ... and the set should be reasonably bright

- If you can't see scan lines in #3, set is most likely out of focus.
- Any Direct View set that achieves #6 has shown some fairly impressive characteristics.

For kicks I did the above on my 34XBR800 ... no overlapping scan lines.
dt, I want you to think about another possible outcome to this test.

Picture the aperature grille in question and lets just for arguments sake say that the line count is some what deficient.

Picture the Sony laying say a .6mm tall beamspot size on .4mm line centers. What is the resultant image on an apearture grille screen? The areas of overlap are actually brighter than the native scan lines themselves. In a relative sense the native lines appear like "scan lines" or a darkened area between lines. I have seen this effect on CRT front projectors and based on the continuous vertical phospors on the Sony, I cant see why such and effect couldnt occur.

You can see this efect in overlapping the two circles generated by two falshlights. The overlapped area will be brighter than the un-overlapped areas.

You would need to examine the screen closely to be sure or be able to progressively increase vertical line count so that the appraoch to overlap is more readily visible. You can do this on a computer monitor. My 19" computer monitor for instance is supposed to support 1600x1200 but the magic full screen without line overlap at reasonable brightness is about 1280x1024. At 1600x1200 you do get this weird bright and brighter scan lines.

ss
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post #110 of 306 Old 11-17-2004, 10:34 PM
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Isnt Joe kane working on an HD DVE? A 1000 line vertical test pattern would be just the ticket.

ss
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post #111 of 306 Old 11-18-2004, 12:16 AM - Thread Starter
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Strangely, the 960 doesn't appear to be capable of converting to 480p or 540p itself. I can see lines in 480i broadcasts on all picture display modes ie progressive, DRC or interlaced. On the other hand it seems to do fine if fed a progressive signal. The picture displayed from my Panansonic RP82 is pristine, with no lines visible. That Ok with me because I would never get the TV to do the progressive conversion when I have a DVD player with a state of the art (or close to it) Farouja de-interlacer.
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post #112 of 306 Old 11-18-2004, 06:28 AM
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Quote:
Originally posted by subysouth
Isnt Joe kane working on an HD DVE? A 1000 line vertical test pattern would be just the ticket.

ss
.... it has been out for a long while, again here is a clip from the Gary Merson review of the 34xbr910 in which he uses the HD DVE to test the resolution and concludes it lines up with 1400 lines. I guess you can lead a horse to water but you can't make him drink.

"I moved on to HDTV signals. I have on hand Joe Kane’s new HD Digital Video Essentials (DVE) on D-VHS D-Theater tape. There are two versions, 720p and 1080i. This set upconverts 720p input signals to 1080i so I choose the 1080i version of the tape for my tests. DVE contains an extensive array of test patterns and some original HD content. I concentrated on its multi-burst patterns, which are used to examine HD display resolution capabilities. The top pattern I could resolve was the 22MHz pattern, which by no coincidence matches up to the set’s super-fine picture tube’s 1400+ horizontal resolution."

And again another link to the full article if you want to actually read it this time ;)

http://www.theperfectvision.com/news...v34xbr910.html
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post #113 of 306 Old 11-18-2004, 08:23 AM
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Quote:
Originally posted by subysouth
When 1080 lines are laid over the back of a aperture grille screen it is debatable whether all of the lines are discretely displayed. When 1080 lines are a laid across the back of a dot mask screen with 611(an example found in the 1st gen Panny 34") vertical dots, there is no longer a debate. The maximum vertical resolution possible is 611, it may be less but never more.

The aperture grille is a compromise in brightness vs bleed. There is NO vertical delineation of phosphor triad stripes and minimal horizontal. Vertical bleed in a set of this nature is IMO a guarantee. Its almost unavoidable.

On the other hand is much more easy to eliminate bleed entirely on a dot mask set because so much material is dedicated to the mask. The downside is lower brightness given the same general screen size. Dimmer but sharper. You are correct that exact opening vs mask dimensions would firm it up, but especially in the vertical some mask is much more likely to reduce bleed than no mask at all correct?

ss

I agree with you 100%, that masking, whether vertical or horizontal, reduces bleeding in those respective directions.

I am less concerned about vertical bleeding compared to horizontal bleeding because it has been shown that the human eye/visual perception process is much more sensitive to horizontal resolution than vertical resolution. Try turning your head sideways for a while reading this text and see how the demarcation between horizontal lines of text (graphics) becomes sharper.

I also agree with you that if the Panny has 611 holes vertically, then it is going to behave like a fixed pixel display with 611 vertical elements. The difference being that for the fixed display, there is a computer trying to intelligently remap 1080 lines to about 700 and in the case of the Panny, the remapping is done mechanically by the shadow mask in a hit or miss fashion.
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post #114 of 306 Old 11-18-2004, 08:39 AM
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Originally posted by subysouth
The nastiest test pattern to test bandwidth is a square wave single pixel alternate black/white vertical stripe pattern.
Does anyone know the maximum pixel format of the photos stored on a Sony Memory Stick taken by a digital Sony camera?

I think the XBR960 tries to remap this high density format into its own internal format, but I don't know what internal format it chooses, 480p or 960i, or 1080i.

Would creating a custom JPEG test pattern with Adobe Photoshop and then displaying it on the XBR960 using the stick reader give us a better idea of how sharp the beam really is?
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post #115 of 306 Old 11-18-2004, 09:32 AM
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Originally posted by Dearth
.... it has been out for a long while, again here is a clip from the Gary Merson review of the 34xbr910 in which he uses the HD DVE to test the resolution and concludes it lines up with 1400 lines. I guess you can lead a horse to water but you can't make him drink.

"I moved on to HDTV signals. I have on hand Joe Kane’s new HD Digital Video Essentials (DVE) on D-VHS D-Theater tape. There are two versions, 720p and 1080i. This set upconverts 720p input signals to 1080i so I choose the 1080i version of the tape for my tests. DVE contains an extensive array of test patterns and some original HD content. I concentrated on its multi-burst patterns, which are used to examine HD display resolution capabilities. The top pattern I could resolve was the 22MHz pattern, which by no coincidence matches up to the set’s super-fine picture tube’s 1400+ horizontal resolution."

And again another link to the full article if you want to actually read it this time ;)

The resolution in question at this juncture is the vertical not the horizontal.

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post #116 of 306 Old 11-18-2004, 09:55 AM
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Originally posted by montreal
I agree with you 100%, that masking, whether vertical or horizontal, reduces bleeding in those respective directions.

I am less concerned about vertical bleeding compared to horizontal bleeding because it has been shown that the human eye/visual perception process is much more sensitive to horizontal resolution than vertical resolution. Try turning your head sideways for a while reading this text and see how the demarcation between horizontal lines of text (graphics) becomes sharper.

I also agree with you that if the Panny has 611 holes vertically, then it is going to behave like a fixed pixel display with 611 vertical elements. The difference being that for the fixed display, there is a computer trying to intelligently remap 1080 lines to about 700 and in the case of the Panny, the remapping is done mechanically by the shadow mask in a hit or miss fashion.
I do agree that the human is somewhat more sensitve in the horizontal by design, however vertical bleed can contribute to an overall softened picture especially if there is more than just bleed, outright overlap.

Is the Panny set not knowingly repainting a large percentage of those next 540 field lines on the same exact phosphors it just painted in the preceding field? It cant light the phosphor triads correctly if it doesnt know their location and count. The Panny set knows its not doing a legitimate 1080i because it doesnt have the seperate pixels to lay the info on, same as the Sony sets know they arent painting more than 850 or 1400 of the theoretical 1920 in the horizontal. These sets know exactly how many horizontal triads they have and in the case of the Panasonic, exactly the vertical too. The Sony gun could be shooting for a given location in the vertical and not an exact triad group because the phosphor is borderless in the vertical. I am however dramatically more comfortable believing the resolution numbers on the Sony H and Panny H&V(albeit much lower.) That Sony V is still loaded with potential issues IMO.

I think all CRTs should function like a fixed pixel device. Any thing above or below the sweet spot of resolution the set is not doing well. Sets should not be being asked to do both 480p and 1080i if a quality picture is desired. There are huge compromises when this is done. For instance, that Panny IMO should always be driven at 611p with all sources. CRTs are really no more or less variable resolution devices than any other display, in that varying the resolution has compromises. Same as it would on a plasma. You could force a 768p plasma to display 480p. The plasma manufacturers have not allowed you at this juncture to shoot yourself in the foot that way, and yet CRT manufacturers are doing it for you. If I believed these sets were truly capable of 1080i or 720p or whatever actual resolution, I would say scale everything to that. I still believe widely disparate sets are bieng asked to do unrealistic things to satisfy "HD" display. If the best picture is really the goal, IMO there is a better way, native rates for all.

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Quote:
Originally posted by montreal
Does anyone know the maximum pixel format of the photos stored on a Sony Memory Stick taken by a digital Sony camera?

I think the XBR960 tries to remap this high density format into its own internal format, but I don't know what internal format it chooses, 480p or 960i, or 1080i.

Would creating a custom JPEG test pattern with Adobe Photoshop and then displaying it on the XBR960 using the stick reader give us a better idea of how sharp the beam really is?

I for one am satisified(and was as soon as I saw montreal's numbers on horizontal pitch) that the Sony can do the 1400 H res and I think bandwidth isnt gonna be a problem either. Other "lesser" 34" sets have exceeded this bandwidth already by a pretty healthy margin.

I would concentrate on resolving the 1080 vertical line performance question. It would seem likely its gonna lock into a lower line count progressive display for still pictures. It would be interesting to see what it did with a 1080 vertical alternating black/white line picture though.

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post #118 of 306 Old 11-18-2004, 10:49 AM
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Originally posted by subysouth
dt, I want you to think about another possible outcome to this test.
1) With Picture turned all the way down, you can see a (very small) distinct, sharp, black gap between scan lines. In your scenerio above, overlapping scan lines would not provide small black line /(sharp transition)/ white line (OK, actually with Picture/Contrast turned down it's small black line / grey line) ... they would provide white line /(fuzzy transition)/ whiter line. Black line / white line is what I'm seeing ... which to me indicates an actual gap.
2) Joe Kane, Guy Kuo, Gary Merson, and others have talked about sets with the inability to properly seperate scan lines for ... well, for longer than I have been in to home theater. It is so easy to test for ... the end results are so obvious. Unfortunately, I don't have a DVHS deck and Digital Video Essentials (or an HD signal generator). However, anyone who 1) does and 2) is at all competent would be able to test this extremely quickly (and would do so while reviewing the set).
3) If, as your suggested, the results at the end of my test above were that scan lines were actually overlapping by 50% ... the reulting picture would be so poor ...

That being said ... yes ... alot of people probably are running their set with overlapping scan lines ...
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One caveat: Do not bump the Contrast/Picture parameter too high. If you do, the resolution will not realize its full potential. With HDTV sources, we ended up with a setting of about 30 percent, which produced approximately 18 footlamberts. That brightness is fine for viewing the TV in dim rooms with the lights off. For DVD and other sources, we were able to switch to around 40 percent and get a significantly brighter picture.
http://hardware.gamespot.com/Story-ST-1341-x-10-11-x

The old light-output vs. resolution issue for CRTs ... which is a valid issue for people looking at this set (will your viewing environment allow for the resolution you're paying $$$ for).

Now, unfortunately I don't have a test to ensure the set is actually scanning at 1080i. The old 'resolvable resolution' vs. 'actual resolution' ... and how CRTs are constructed ... prevents me from knowing how to actually test for that. Perhaps there is a way, but I don't know of it.

However, since
1) Sony explicitly states that it does
2) It's part of the CEA's labeling requirements for HDTV ... over manufacturers would likely take issue if it didn't
3) I have seen no credible information to suggest otherwise

I'm going to go with 1080i ... not overlapping.
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Originally posted by dt_dc
1) With Picture turned all the way down, you can see a (very small) distinct, sharp, black gap between scan lines. In your scenerio above, overlapping scan lines would not provide small black line /(sharp transition)/ white line (OK, actually with Picture/Contrast turned down it's small black line / grey line) ... they would provide white line /(fuzzy transition)/ whiter line. Black line / white line is what I'm seeing ... which to me indicates an actual gap.
2) Joe Kane, Guy Kuo, Gary Merson, and others have talked about sets with the inability to properly seperate scan lines for ... well, for longer than I have been in to home theater. It is so easy to test for ... the end results are so obvious. Unfortunately, I don't have a DVHS deck and Digital Video Essentials (or an HD signal generator). However, anyone who 1) does and 2) is at all competent would be able to test this extremely quickly (and would do so while reviewing the set).
3) If, as your suggested, the results at the end of my test above were that scan lines were actually overlapping by 50% ... the reulting picture would be so poor ...

That being said ... yes ... alot of people probably are running their set with overlapping scan lines ...
http://hardware.gamespot.com/Story-ST-1341-x-10-11-x

The old light-output vs. resolution issue for CRTs ... which is a valid issue for people looking at this set (will your viewing environment allow for the resolution you're paying $$$ for).

Now, unfortunately I don't have a test to ensure the set is actually scanning at 1080i. The old 'resolvable resolution' vs. 'actual resolution' ... and how CRTs are constructed ... prevents me from knowing how to actually test for that. Perhaps there is a way, but I don't know of it.

However, since
1) Sony explicitly states that it does
2) It's part of the CEA's labeling requirements for HDTV ... over manufacturers would likely take issue if it didn't
3) I have seen no credible information to suggest otherwise

I'm going to go with 1080i ... not overlapping.
Maybe - maybe not. Without out an appropriate test pattern or a known line deficient count on the set(particularly with you dropping contrast) I am not sure what you are seeing isnt what I described.

On your quoted paragraph, increasing contrast effectively increases beam spot size along with brightness. You might interpret the above to say, that too high a contrast creates line overlap and that a relatively low contrast is required to control it.

Also on the issue of manufacturers calling each other on actual resolution or the feds calling them on it.

Like I cited earlier Gary Merson and WSR KNEW and published that the $6500 1st gen set by Panasonic being sold as a 1080i set had only 611 vertical hole count in its dot mask. Even if you ignored the horizontal, which was still defined at that point at 1920, for 1080i, the 1080 still had to be satisfied, but it clearly wasnt on the Panny by a large margin. Theres no discussion on what its full vertical res potential was. Its maximum is 1117x611 and yet no feds stopped Panasonic from selling the set and Sony et al didnt call them on it. Wanna know why I think that is? People in glass houses dont throw stones. Even if by some miracle the latest Sony 34" "HD" sets are producing 1400x1080i(still not full 1080i,) what about all the earlier non-Super Fine pitch sets Sony et al have already sold as HD? You think they want to open that can of worms? You get consumers begining to question what 1080i is and the consensus is gonna turn out at 1920x1080i, and other consumers will agree. Can you see the probs?

We can because of the design of Sony's set have an interesting discussion about what its vertical res potential is. Other dot mask sets dont have that luxury. And just because we can discuss it on the Sony, doesnt mean its doing the 1080 vertical lines IMO - the jury is still way out on that point. Like I said earlier my hat is off for Sony dialing in 1400 in the horizontal(although youre gonna need to sit close to appreciate) but by comparison thats a cakewalk compared to doing the V 1080 without overlap on an aperature grille set. There should be a vertical test pattern on HD DVE.

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post #120 of 306 Old 11-18-2004, 11:42 AM
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Originally posted by subysouth
Is the Panny set not knowingly repainting a large percentage of those next 540 field lines on the same exact phosphors it just painted in the preceding field? It cant light the phosphor triads correctly if it doesn't know their location and count.
Most modern TVs use digital timers and precision DACs to make sure that as the vertical amplifier places each new horizontal line below the previous one, the line positioning on the alternate frame is exactly a half line height lower than the line positioning of the previous frame. This slight offset is all the difference that there is between 540p and 1080i (or 480p and 960i). In spite of this, the guns blindly paint the lines not knowing how well the beams are going to line up with the shadow mask holes.

It is impossible to record the X Y coordinate position of each of the half million holes in the mask into the computer memory so that the beam position can be dynamically corrected on the fly for each hole location.

Assuming you could achieve such a perfect alignment in the factory, by the time the TV gets transported to the owner and gets subject to all the thermal, magnetic, and mechanical stresses that take place over time, the original performance would be so badly corrupted that no advantage would have been gained by this exercise.

So the general approach is to just shoot all the electron bullets in a fixed mechanical way and hope that the net result looks reasonable. Anyone who has ever done a static convergence of the three guns on a color TV knows what I mean when I say that CRTs are a compromise taken to reconcile many competing forces. We accept these geometric compromises because in return we get an image with a greater contrast ratio and perhaps better color purity than with fixed pixel displays.

Quote:
Originally posted by subysouth
[b]The Panny set knows its not doing a legitimate 1080i because it doesn't have the separate pixels to lay the info on, same as the Sony sets know they aren't painting more than 850 or 1400 of the theoretical 1920 in the horizontal.B]
The world is not made up of visual textures boxed at 1920 units per panorama width. The world is an analog place. We chop the image up into an arbitrarily chosen format of 1920 units for transmission purposes but quickly try to melt the 1920 units back into one continuous streak as faithfully as audio CDs try to recreate music by blending 44 thousand samples together each second. The goal in audio is not to synchronize the sampling rate with the frequency of the guitar string. It to make analog momentarily digital and then analog again.

Therefore the Sony and Panny need not care if the analog scan line painted by each gun takes into account the number of horizontal holes in the shadow mask and the number of pieces of data in a transmission signal. The guns have already forgotten that the signal arrived as 1920 discrete units of data per line. To do its job properly the gun doesn't want to know this fact. Each gun just wants to spray a continuously varying stream of electrons squarely onto the solid block of monotone phosphor that it sees laying behind the holes in the mask. Each gun sees a block of a different primary color. (The Sony may have one gun, but this single gun has three different barrels spaced side by side.)

It is the precision mechanical positioning of the mask in the factory that determines if there is a straight line of site between each red phosphor spot on the inside of the screen and the end of the barrel of the red gun located some 20 inches back. Same for the other two colors. Because it is hard to get this perfect for all half million red phosphor spots, purity magnets have to be added afterward to coax the beam to bend slightly to prevent corruption on the edges of the screen. Once this is done, you are stuck with what might be slight bowing of vertical and horizontal lines that may appear at different locations on the screen. To correct these, the computer can slightly adjust the deflection amplifiers dynamically, but these corrections are generalized over large areas and not particular locations on the screen where bowing is occurring.
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