FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Debian > Debian User

 
 
LinkBack Thread Tools
 
Old 09-20-2012, 08:06 PM
Lionel Trésaugues
 
Default Display hurtful on LCD screen with Wheezy

LCDs work by blocking the white light from the backlight. If the pannel is
leaking UV, the leak should be worse on bright images (probably those with
brighter red and blue channel values).

But it really should not be leaking any relevant amount of UV in the first
place.
Very interesting. But it might be difficult to check if that's the case
without specialized devices, no ?



--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org

Archive: 505B7731.60108@gmail.com">http://lists.debian.org/505B7731.60108@gmail.com
 
Old 09-20-2012, 08:37 PM
Neal Murphy
 
Default Display hurtful on LCD screen with Wheezy

On Thursday, September 20, 2012 03:55:48 PM Lionel Trésaugues wrote:
> > And the sub-pixel order is equal too?
>
> The sub-pixel order is set to rgb (like I do in Ubuntu). I can
> definitely see a (worse) change if I use a different mode.
> Disabling the sub-pixel smoothing didn't improve anything relatively to
> the pain generated by the exposure to the screen.
>
> I'll come back to all of you in three days with some pictures to allow
> you to properly compare the rendering in Ubuntu-based distro (currently
> Maya13) and Debian Wheezy with the same graphic drivers, on the same
> computer.
>
> Nevertheless, to me, it seems that one of the best way to properly
> identify and describe in a more objective manner my issue should be to
> get on of these color calibrator such as the ColorHug.
>
> Until them, I'll keep on reading the thread in silence, but please, stay
> calm and respectuous with each other : my issue is not worth turning
> people mad at each other

Come now. It just isn't a proper internet discussion without a flamewar thrown
in.

I forget if you said you are using an LCD or a CRT. I believe you said you've
tried different monitors and different video cards. How about cables? Can you
switch between VGA and DVI cables?

Other things that come to mind.
- have you turned the brightness/contrast down
- if you don't need correct colors, can you reduce R, G and/or B until
whites are neutral or slightly on the red/yellow side?
- how about adjusting gamma?
- if a CRT, can you (or anyone with very good ears) hear a very high pitched
whine, nearly in the ultrasonic spectrum? A bad cap in a CRT will give
me a headache in mere minutes.
- if a CRT, does the display waver or shimmy at all?

That one GNU/Linux distro is OK and Debian causes trouble somewhat befuddles
me. Does Debian now stand for DEranges Brains In A Nanosecond? Should it be
nicknamed Torquemada?


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: 201209201637.43866.neal.p.murphy@alum.wpi.edu">htt p://lists.debian.org/201209201637.43866.neal.p.murphy@alum.wpi.edu
 
Old 09-20-2012, 08:37 PM
Lisi
 
Default Display hurtful on LCD screen with Wheezy

On Thursday 20 September 2012 20:50:40 Mark Allums wrote:
> You were obsessed with the refresh rate.

This is absurd. I mentioned it twice, amid a lot of other things. It is you
who are obsessed.

If you want to continue this absurd attack on me, may I suggest that you go
off list.

Lisi


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: 201209202137.50169.lisi.reisz@gmail.com">http://lists.debian.org/201209202137.50169.lisi.reisz@gmail.com
 
Old 09-20-2012, 08:52 PM
Mark Allums
 
Default Display hurtful on LCD screen with Wheezy

On 9/20/2012 3:37 PM, Lisi wrote:

On Thursday 20 September 2012 20:50:40 Mark Allums wrote:

You were obsessed with the refresh rate.


This is absurd. I mentioned it twice, amid a lot of other things. It is you
who are obsessed.

If you want to continue this absurd attack on me, may I suggest that you go
off list.

Lisi





I'm not attacking you. On the contrary, I am the one who feels attacked.



--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org

Archive: 505B820E.2040507@allums.com">http://lists.debian.org/505B820E.2040507@allums.com
 
Old 09-21-2012, 12:00 AM
Ralf Mardorf
 
Default Display hurtful on LCD screen with Wheezy

On Thu, 2012-09-20 at 16:01 +0100, Lisi wrote:
> On Tuesday 18 September 2012 22:31:21 Lionel Trésaugues wrote:
> > I am experiencing a physical pain whenever I am in front of my
> > computer running either Debian (Wheezy) or Debian-based distributions
> > (such as Mint LMDE, XFCE or MATE edition). Switching from XFCE to MATE
> > doesn't lead to any improvements .
> >
> > My eyes start to suffer and soon, I can feel that an headache is coming.
> >
> > I don't have this feeling at all when I am running either Ubuntu or
> > any Ubuntu-based distribution (Mint XFCE or Cinnamon edition).
>
> Is there any possibility that more of the ultra-violet end of the spectrum
> might be displaying in the Debian list of distros than in the Ubuntu list?
>
> If so, that could certainly cause the problems that Lionel mentions, but I
> know too little about the colour reproduction involved to know whether it is
> possible. If this could be the case, how could Lionel change it?
>
> Lisi

CRT monitors could emit less UV light and LCD displays don't emit UV
light. Xeroderma Pigmentosum patients and vampires shouldn't get
problems using a CRT or LCD, see http://www.xps.org/uvnotes.htm .


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: http://lists.debian.org/1348185608.1272.43.camel@localhost.localdomain
 
Old 09-21-2012, 12:16 AM
Ralf Mardorf
 
Default Display hurtful on LCD screen with Wheezy

On Thu, 2012-09-20 at 11:30 -0400, Joey Hess wrote:
> Inaudible or barely audible noise from either the computer or the
> monitor, possibly created by specific clocks cycles of a particular
> software load. (TV sets do this to me all the time.)
> Try turning the monitor off and staying in front of the
> computer, or leaving it on but with the display obscured to check,
> or find a younger pair of ears who may be able to hear higher
> pitches.

The noise will change regarding to the frequency of CRT monitors. But
what should cause noise for LCD displays? A serious question, since I
don't have experiences with LCDs. The parts that make noise for a CRT
aren't parts of LCDs.

The switching power supply of a LCD display could cause high frequency
noise, but no software settings will change the noise a power supply
will make. Power supplies with classic transformation only could cause
low frequency noise.


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: http://lists.debian.org/1348186614.1272.51.camel@localhost.localdomain
 
Old 09-21-2012, 12:23 AM
Ralf Mardorf
 
Default Display hurtful on LCD screen with Wheezy

On Thu, 2012-09-20 at 08:42 -0700, T Elcor wrote:
> ----- Original Message from Lionel Trésaugues -----
>
> > Lowering the brightness helps a little bit to make the pain more bearable,
> > but it is still unpleasant and hurtful after a while.
>
> Another thing you may want to try is to connect your monitor through the VGA connector instead of DVI, if you have the right cable.
>
> Not sure if that would help, just curious if that would make any difference.

Analog cables could cause echos . For computer screens digital for
sure is better, even while analog is better for many other things. OTOH
failure might compensate something that's related to the OPs issue.



--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: http://lists.debian.org/1348187038.1272.56.camel@localhost.localdomain
 
Old 09-21-2012, 12:38 AM
Ralf Mardorf
 
Default Display hurtful on LCD screen with Wheezy

I don't remember, you still have Ubuntu installed too?

If not, it might be possible that the LCD display gets broken in the
meantime, so even degassing of broken semiconductor could be possible or
emission of ozone and of course the picture could be less good too.


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: http://lists.debian.org/1348187935.1272.62.camel@localhost.localdomain
 
Old 09-21-2012, 12:56 PM
Ralf Mardorf
 
Default Display hurtful on LCD screen with Wheezy

On Thu, 2012-09-20 at 16:37 -0400, Neal Murphy wrote:
> Come now. It just isn't a proper internet discussion without a
> flamewar thrown in.

But an OT t the subject for the flame would be nice.

> - if a CRT, can you (or anyone with very good ears) hear a very high
> pitched whine, nearly in the ultrasonic spectrum? A bad cap in a CRT
> will give

The OP has got a LCD. Btw. there are different parts inside a CRT that
can cause high frequency noise.


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: http://lists.debian.org/1348232164.1108.54.camel@localhost.localdomain
 
Old 09-26-2012, 02:12 PM
Lionel Trésaugues
 
Default Display hurtful on LCD screen with Wheezy

All right.

Some users have asked me to upload some screenshots. So, here they are !
The ones I obtained using Ubuntu got "Ubuntu" in their filenames and the
ones from Debian, "Debian" in their filenames.
I tried to take screenshots as similar as they could be from the two
different OS (using the same desktop environment (XFCE) and the same
fonts settings (96dpi, default font= Sans, 10pt, LCD hinting, slight,
enabled antialiasing).
Screenshots have been taken with shutter, some using xmag as suggested
(in that case, it is also mentioned in the filename).


http://i1058.photobucket.com/albums/t405/Alkalyzer/Ubuntu_Xmag_Terminal_zps95bc0438.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Debian_Xmag_terminal_zps4013e48d.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Ubuntu_Xmag_LibreOffice_Writer_zpsa01ef21c.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Debian_Xmag_LibreOfficeWriter_zpsb4fce188.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Ubuntu_Xmag_Desktop_zps0e433819.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Debian_Xmag_Desktop_zps0727d52b.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Ubuntu_Terminal_zps83103ab7.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Debian_Terminal_zps1867e859.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Ubuntu_LibreOfficeWriter_zpsdb0f8467.png
http://i1058.photobucket.com/albums/t405/Alkalyzer/Debian_LibreOffice_Writer_zpsbf2a133d.png

Because I don't have the same background on Debian and Ubuntu, the
background color look different between the pictures named
"...Desktop...png"


And, to answer a previous question, I am still running Ubuntu and Debian
on the same machine through dual-boot, so we can exclude a hardware
trouble that would have happened to the display.


I'll now try to install a rpm based distro to see if the problem is
Debian-specific.



--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org

Archive: 50630D67.80705@gmail.com">http://lists.debian.org/50630D67.80705@gmail.com
 

Thread Tools




All times are GMT. The time now is 09:46 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright ©2007 - 2008, www.linux-archive.org