NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/rec/video/16513

Internet Message Format | 1993-01-28 | 5.3 KB

Path: sparky!uunet!think.com!spool.mu.edu!sdd.hp.com!crash!cmkrnl!jeh
From: [e-mail]
Newsgroups: rec.video
Subject: Re:  SONY.....may they rot in hell !!
Message-ID: <[e-mail]>
Date: 27 Jan 93 22:57:30 PST
References: <[e-mail]>
Organization: Kernel Mode Systems, San Diego, CA
Lines: 111

> Apparently Mr. Ricciardi had a problem with geometric
> distortion on his set (as do others) and have felt obligated to either
> attempt adjustment themselves or have called their sets in for service.

In my case, both.  (And I have some experience with tv setup -- and I have
the requisite test equipment.)  The service techs say "that's as good as it
can get".  After fiddling with the adjustments for several hours, I conclude
that they're right.  Meaning that it's a design deficiency, not a problem in
the particular set.

This does NOT mean that it isn't a problem.

> From what I understand, the techs either can't or won't "fix" them and
> fixing the sets themselves is not working.

Yup.

>  Did the sets in the showroom exhibet this problem? If so, why did these

("exhibit".)

> individuals buy them? If they didn't, than thats a different story.

("that's".)

It is not easy to evaluate a set for this complaint in the showroom, unless one
has access to a test pattern generator.

The problem is that lines that are supposed to be horizontal, and which are
near the top or bottom of the screen, bend inward near the left and right
corners.  I can't show this easily with Ascii graphics, but if you imagine the
following:

        / / | | | \ \
        | | | | | | |
        | | | | | | |
top     | | | | | | |  bottom
        | | | | | | |
        | | | | | | |
        | | | | | | |
        \ \ | | | / /

turned 90 degrees left or right, you'll get the idea.

Unless you happen to catch a news program, or something else, that uses
graphics that (a) contain horizontal lines extending the full width of the
screen, near the top or bottom, and (b) hold these lines for long enough to
make the problem obvious, you may not spot it.  Most camera shots don't contain
such features nor do they stay in one place long enough to be certain there is
a problem.  (You might think that that's the way it's supposed to look.  And
anyway, your attention is normally nearer the center of the screen.)

You do notice it, however, when (for example) a camera angle pans across
something like a building  that is *obviously* made up of straight lines, and
and the straightness of the lines changes as they move through the screen.  It
is noticeable even on lines that aren't horizontal, as they will acquire an
extra "bend" if they move into the affected areas.

One place it shows up a LOT is on Star Trek:TNG, if you look at the
straightness of the warp engines as the ship moves through the screen.

Unless you're primed to look for it, you may never notice it.  Once you are
looking for it, though...

There are adjustments in the "service menu" for pincushion distortion in
*vertical* lines (imagine the above illustration, NOT turned on its side), but
in horizontal lines it is corrected by moving these funny little permanent
magnets around on the back of the CRT.  Moving these magnets also affects
convergence.  The trouble with that tradeoff is that you'll notice convergence
errors all the time.

> From my own experience, I've owned Sony tv sets now including my current 27"
> XBR for fifteen years now. I have never experienced a problem and absolutely
> love the picture. I personally know four people with 27" Sonys (XBR and
> Trinitron sets) that have no problems whatsoever with either reliability or
> geometric distortion.

Like I said, unless you're primed to look for it...

And, truthfully, even then, it doesn't jump out at you all that often.

It's just that for the money Sony charges for these sets, they ought to be just
as perfect as the technology allows.  And we DO know how to correct for this
problem.  Hell, the Heathkit color tv (basically an RCA design) I built for my
parents in *1967* had two simple adjustments which corrected for this.

> I would wholeheartedly purchase another Sony tv set in the future.

The only way I will buy *any* 27" (or larger) set, from any manufacturer,
in the future is to ask that it be un-boxed in the store, and then I will play
selected bits of Reference Recordings' _A Video Standard_ LD on it, checking
for this and other problems.

> I just wanted to place a different viewpoint onto the net so that people
> don't think that Sony XBRs are total garbage to be avoided. I'm a happy owner
> along with four of my friends.

Frankly, I have seen this on enough 27" (and larger) sets that I suspect that
the distortion is there -- you and your friends simply aren't noticing it.  In
which case, GOOD FOR YOU!  (It'd be far easier to not be so nit-picky...)

> I hope the people who are having problems that are legitimate will acquire
> satisfation.

Based on reports seen here in rec.video for at least the last two years, the
prospects for this aren't good.  We haven't heard from anyone who has
complained about this problem and had it resolved to their satisfaction.
(This is an invitation for anyone who HAS had it resolved, to speak up...)

    --- Jamie Hanrahan, Kernel Mode Systems, San Diego CA
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