# factory cheated? confused by CRT horizontal dot pitch and vertical dot pitch!

N

#### netwom

Hi all,

I am trying to understand how CRT RGB triads work as pixels and I have done
some simple geometry calculations.

Here is a nice webpage and have a nice picture showing the dot pitches.

I perfectly understand the definition of the horizontal dot pitch and
vertical dot pitch and diagonal dot pitch.

However, when it comes to some simple calculation, I got confused:

I have a LG Studioworks 995E CRT monitor, its max physical viewable size is
366mm x 274 mm, and its max resolution is 1600 x 1200, its diagonal dot
pitch is 0.26mm.

Horizontal dot pitch is 0.26*0.866=0.2252mm.
Vertical dot pitch, according to that article and many other article on the
Internet, equals the diagonal dot pitch, so it is 0.26mm.

366/1600= 0.2288mm/pixel, that's almost 0.2252, so I have no problem with
this result.

Now comes to the problem:

274/1200=0.2283mm/pixel, which is not the vertical dot pitch(which should be
0.26mm(see above)).

But 0.26mm, the vertical dot pitch, according to its definition, should be
the distance between two vertically adjacent pixels.

If that distance is vertical dot pitch and is 0.26mm, the maximal vertical
resolution will never be 1200, it should be 1054 pixels.

See the problem?

The factory claimed it to have a vertical max resolution of 1200 pixels, but
actually from the vertical dot pitch, it should only have 1054 pixels. So
the factory cheated?

Any thoughts? Please correct me if I am wrong!

Thank you very much,

-Net

N

#### netwom

netwom said:
Hi all,

I am trying to understand how CRT RGB triads work as pixels and I have done
some simple geometry calculations.

Here is a nice webpage and have a nice picture showing the dot pitches.

I perfectly understand the definition of the horizontal dot pitch and
vertical dot pitch and diagonal dot pitch.

However, when it comes to some simple calculation, I got confused:

I have a LG Studioworks 995E CRT monitor, its max physical viewable size is
366mm x 274 mm, and its max resolution is 1600 x 1200, its diagonal dot
pitch is 0.26mm.

Horizontal dot pitch is 0.26*0.866=0.2252mm.
Vertical dot pitch, according to that article and many other article on the
Internet, equals the diagonal dot pitch, so it is 0.26mm.

366/1600= 0.2288mm/pixel, that's almost 0.2252, so I have no problem with
this result.

Now comes to the problem:

274/1200=0.2283mm/pixel, which is not the vertical dot pitch(which should be
0.26mm(see above)).

But 0.26mm, the vertical dot pitch, according to its definition, should be
the distance between two vertically adjacent pixels.

If that distance is vertical dot pitch and is 0.26mm, the maximal vertical
resolution will never be 1200, it should be 1054 pixels.

See the problem?

The factory claimed it to have a vertical max resolution of 1200 pixels, but
actually from the vertical dot pitch, it should only have 1054 pixels. So
the factory cheated?

Any thoughts? Please correct me if I am wrong!

Thank you very much,

-Net

I also found this happens not only to my Studioworks 995E monitor. It also
occurs in other CRT monitors. Millions of users have been misled and cheated
by the manufactor... Do you think so?

R

#### Rick

netwom said:
I also found this happens not only to my Studioworks 995E monitor. It also
occurs in other CRT monitors. Millions of users have been misled and cheated
by the manufactor... Do you think so?

Much of the info in that article is either misleading, obsolete or
diagonal dot pitch may or may not equal vertical dot pitch. It
depends entirely on the design of the mask.

Your best bet is to email LG Electronics and see what they tell
you. It might take several tries to get to someone who can

Rick

T

#### Testy

I think you have WAY too much free time on your hands.

Testy

G

#### Guest

DOn't think that LG could make false claims about the performance of their
products. Many countries have punitive trade practices rules that would see
them heavily fined.

Get onto LG web site and dig deeper into their Tech Specs.

You seem to have plenty of time to check this out.

BTW if you are right: what can you do about them 'cheating'?

J

#### Jim Macklin

Diagonal dot pitch is an average.
1600/366=4.371584699453551912568306010929 or
0.22833333333333333333333333333333 and
1200/274=4.379562043795620437956204379562 or
0.22833333333333333333333333333333

The pixels seem to be the same distance apart.

Perhaps "some simple geometry calculations" fail when doing
such calculations. Likely some calculus and rounding errors
creep in.

Have you asked LG for their methods?

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.

| DOn't think that LG could make false claims about the
performance of their
| products. Many countries have punitive trade practices
rules that would see
| them heavily fined.
|
| Get onto LG web site and dig deeper into their Tech Specs.
|
| You seem to have plenty of time to check this out.
|
| BTW if you are right: what can you do about them
'cheating'?
|
| "netwom" wrote:
|
| > Hi all,
| >
| > I am trying to understand how CRT RGB triads work as
pixels and I have done
| > some simple geometry calculations.
| >
| > Here is a nice webpage and have a nice picture showing
the dot pitches.
| >
| > I perfectly understand the definition of the horizontal
dot pitch and
| > vertical dot pitch and diagonal dot pitch.
| >
| > However, when it comes to some simple calculation, I got
confused:
| >
| > I have a LG Studioworks 995E CRT monitor, its max
physical viewable size is
| > 366mm x 274 mm, and its max resolution is 1600 x 1200,
its diagonal dot
| > pitch is 0.26mm.
| >
| > Horizontal dot pitch is 0.26*0.866=0.2252mm.
| > Vertical dot pitch, according to that article and many
other article on the
| > Internet, equals the diagonal dot pitch, so it is
0.26mm.
| >
| > 366/1600= 0.2288mm/pixel, that's almost 0.2252, so I
have no problem with
| > this result.
| >
| > Now comes to the problem:
| >
| > 274/1200=0.2283mm/pixel, which is not the vertical dot
pitch(which should be
| > 0.26mm(see above)).
| >
| > But 0.26mm, the vertical dot pitch, according to its
definition, should be
| > the distance between two vertically adjacent pixels.
| >
| > If that distance is vertical dot pitch and is 0.26mm,
the maximal vertical
| > resolution will never be 1200, it should be 1054 pixels.
| >
| > See the problem?
| >
| > The factory claimed it to have a vertical max resolution
of 1200 pixels, but
| > actually from the vertical dot pitch, it should only
have 1054 pixels. So
| > the factory cheated?
| >
| > Any thoughts? Please correct me if I am wrong!
| >
| > Thank you very much,
| >
| > -Net
| >
| >
| >
| >
| >
| >
| >
| >
| >
| >
| >

J

#### Jim Macklin

Look at the answer to your other post on the same subject.
Vertical and horizontal pixel are equally spaced, diagonal
pitch is just an advertising average.

1600/366=4.371584699453551912568306010929 inverted =0.22875
1200/274=4.379562043795620437956204379562 inverted
=0.22833333333333333333333333333333

Rounding errors, pixels that are not visible, LG engineers
build hardware, LG salesmen sell hype.

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.

| I think you have WAY too much free time on your hands.
|
| Testy
|
| | > Hi all,
| >
| > I am trying to understand how CRT RGB triads work as
pixels and I have
| > done
| > some simple geometry calculations.
| >
| > Here is a nice webpage and have a nice picture showing
the dot pitches.
| >
| > I perfectly understand the definition of the horizontal
dot pitch and
| > vertical dot pitch and diagonal dot pitch.
| >
| > However, when it comes to some simple calculation, I got
confused:
| >
| > I have a LG Studioworks 995E CRT monitor, its max
physical viewable size
| > is
| > 366mm x 274 mm, and its max resolution is 1600 x 1200,
its diagonal dot
| > pitch is 0.26mm.
| >
| > Horizontal dot pitch is 0.26*0.866=0.2252mm.
| > Vertical dot pitch, according to that article and many
other article on
| > the
| > Internet, equals the diagonal dot pitch, so it is
0.26mm.
| >
| > 366/1600= 0.2288mm/pixel, that's almost 0.2252, so I
have no problem with
| > this result.
| >
| > Now comes to the problem:
| >
| > 274/1200=0.2283mm/pixel, which is not the vertical dot
pitch(which should
| > be
| > 0.26mm(see above)).
| >
| > But 0.26mm, the vertical dot pitch, according to its
definition, should be
| > the distance between two vertically adjacent pixels.
| >
| > If that distance is vertical dot pitch and is 0.26mm,
the maximal vertical
| > resolution will never be 1200, it should be 1054 pixels.
| >
| > See the problem?
| >
| > The factory claimed it to have a vertical max resolution
of 1200 pixels,
| > but
| > actually from the vertical dot pitch, it should only
have 1054 pixels. So
| > the factory cheated?
| >
| > Any thoughts? Please correct me if I am wrong!
| >
| > Thank you very much,
| >
| > -Net
| >
| >
| >
| >
| >
| >
| >
| >
| >
| >
|
|
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