Why is there nobody who can say what are the vertical resolutions are?

[avhed]

On another forum, someone wrote : the super fine pitch of the sony XBR/XS is ~
800+
: the fine pitch, for eg., my Panny CT-30WX15 is~
600+
I counted part of the Panny screen, and there appears to be more?
Do I have to count half the whole height to be accurate, or is the increase of the pixel size to towards the edge linear? If it is, would I be able to count a section of the middle and top, and then average the two out, for a reasonably accurate count?

[kny3twalker]

if you can count them vertically and horizontally I would be interested in the results

[Porcupine2]

What do you mean by vertical resolution?

From what I understand CRTs don't have a vertical resolution, they only have a horizontal resolution. Vertically all HDTV CRTs are 1080 scan lines, simple as that.

There is a vertical "dot pitch" on shadow mask CRTs but that actually doesn't do much. The scanlines still determine everything.

On Trinitrons (aperture grille) they don't even have phosphor separators in the vertical direction. Aperture Grills are just lots and lots of columns (as opposed to lots and lots of dots/rectangles on shadow masks).

[avhed]

I guess I still have to educate myself on the vertical lines work, because they look fixed to me. Is the resolution limited by the openings in the mask?
I asked at on The Home Theater Forum 8 days ago that I am skeptical about the 1080 lines. No replies!

[kny3twalker]

it most probably does not have 1080 resolution vertically
there is probably just some overlap as I understand it

[Porcupine2]

There is indeed some overlap due to the beam thickness but since the odd and even lines are displayed at different instances in time, they can still be considered to be a true 1080 lines (interlaced, though, so only every 1/30th of a second) despite some overlap.

If, on the other hand, you were trying to do 1080p but you still had tons of overlap, things get a bit more debatable, I'd say.

[avhed]

Porc, the scan lines have to scan where the dots are? So are they not the same thing? Am I lost?

[Porcupine2]

I used to think the same thing so I know where you are coming from, avhed. The thing that many people don't realize, is that one dot (square, rectangle, whatever) on a CRT screen is NOT forced to glow with the same intensity everywhere inside that dot. So within one dot you still have infinite information in a sense. This isn't true for LCDs and Plasmas, their dots can only display with the same intensity everywhere inside the dot, so that is why they are called fixed-pixel displays while CRTs are not.

The dot pitch on a CRT screen still limits horizontal resolution in a sense because the screen is structured such that the dots are Red/Green/Blue/Red/Green/Blue/... like that. But vertically the dots just go down as Red/Red/Red/Red.....and the next column over they go down as Green/Green/Green..... etc.

Some older shadow mask tube TVs instead of using tiny dots or squares use tiny rectangles that look like this "|". Screen is like:

|||||||||||
|||||||||||
|||||||||||

or something similar, instead of squares or dots. I'm not sure why they even bother to separate the screen pixels/phosphors in the vertical directon on shadow masks. I think it's just because it is easier to make them that way. If you look at the Sony Trinitions, which are aperture grille, not shadow mask, they are just vertical lines running down the screen with no vertical dot separation at all.

The scan lines actually DON'T bother trying to scan exactly where the dots are. They just scan and couldn't care less where the dots separate themselves vertically. A lot of TVs have Service Menu adjustments that allow you to resize the displayed image right? That's done by resizing the scanlines. When resizing them obviously you can't keep the scanlines firing exactly into the dots.

[avhed]

Porc, thanks for the info. I started going through the 238 pages of Direct View Archives this evening and am reducing my confusion and ignorance.
It would be nice to find a good book on this subject, but by the time I read it, CRTs will probably of little interest to me because of the new screen technologies.

[kny3twalker]

try this site

http://repairfaq.ece.drexel.edu/sam/crtfaq.htm

[lzzy]

[QUOTE=cireaasirefan]Very well said. This is something I can't never write.[/QUOTE]


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