CurtPalme.com Home Theater Forum

[cmjohnson]

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After having made multiple passes through all the focus and sharpness related adjustments on my freshly overhauled and
freshly retubed Marquee Ultra with LUG tubes, I'm now reaching the point where I'm seeing clearly defined scan lines in full 1080p HD that I've never been able to achieve before.

I'm not talking about seeing individual scan lines when using a one line on, one line off test pattern, I'm talking about being able to see individual scan lines on a full single color raster.

My focus adjustment methodology is to select an input source with my target resolution active, which these days may be
assumed to be 1080p. and I then increase vertical size to make the image as tall as possible. Then, with the contrast turned down and me looking right into the CRT faces, I adjust focus, astig, and magnetics for maximum edge and corner sharpness and defined scan lines visible in the characters generated by the projector's internal adjustment screens and patterns.

I then start shrinking the vertical screen size and rework the adjustments whenever the visible scan lines become less clear.

I'm not quite getting defined scan lines at normal contrast levels (50 to 60) and with the vertical height shrunk down to be correct for watching DVDs or Blu-Rays (7 in the case of my PJ) but I'm not far from it. I was able to get the height down to 35 before I was sure that I could no longer see defined scan lines in any tube at any point on the rasters.

I suppose I could figure out the effective resolution at the vertical height setting that marks the maximum effective vertical
resolution that scan lines could be made out at.

I'd like to know, for comparison's sake, what is the highest effective resolution/setting you've been able to see individual
scan lines at, as seen on a full raster and not on a test pattern featuring 1 on, 1 off resolution patterns.


Because, while it looks very good indeed to my eye, I have not personally seen an operating high end CRT home
theater installation in several years. I don't know if the focus performance I'm getting out of these LUG tubes is
what it should be or am I really getting near the limit? Or should I still expect that substantial improvements can be made?

Tonight's viewing material was Finding Dory, and as I continuously refined the focus and sharpness performance, this
good looking movie just kept looking better and better. It ended up being quite stunning after my third full pass through the whole system. And sharp, with real detail in the picture content that's quite comparable to what my JVC RS45 D-ILA projector is able to deliver, only without the artificial pixel array sharpness characteristic of any digital display blessed with a lens that has enough resolution capacity to show those individual pixels.

[greg9518lc]

Well this is from my projector 1080P 100% Ire white field. So I would say I have the sharpest in this thread since
I can post a pic of the scan lines in my image .

Stock yokes and magnetics setup by a friend of mine 110" screen with HD10L 3m lenses that kick ass.........

cellphone pic

[cmjohnson]

Nice. You get bonus points for doing it on a white screen.

I base my evaluations on a per-color basis because on a Marquee the minimum convergence step size is big enough that I can't guarantee being able to match up all colors exactly.

So, showing 1080p scan lines on a white field is very impresive. How is it on green only?

I think that Marquee convergence can be made finer but at the expense of convergence adjustment range by reducing
the gain of the convergence amplifiers. Or by adding dropping resistors in the convergence yokes. The catch to this is
obviously that you'll need a setup that demands little convergence. A longer throw to screen with smaller angles on red and blue would be desirable.

[greg9518lc]

1080p 72hz 178mhz blue convergence off kurt