123Macmini.com
FAQFAQ   SearchSearch   MemberlistMemberlist   GalleryPhoto Gallery   RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Rotating screens 90 deg alters perceived picture quality

 
Post new topic   Reply to topic    123Macmini.com - Forums Forum Index -> Mac Accessories
View previous topic :: View next topic  
Author Message
JohnnyBoy
Veteran Member
Veteran Member


Joined: 13 Jul 2007
Posts: 3954
Location: West Sussex, South-East England

PostPosted: Fri Apr 16, 2010 12:29 pm    Post subject: Rotating screens 90 deg alters perceived picture quality Reply with quote

I've currently got my Mini linked to two 20" displays in 'landscape' orientation. This gives a total desktop resolution of 3200 x 1200 pixels, which is very wide picture shape, 8:3.

But these screens can pivot thru 90 degrees into 'portrait' orientation. When I realised that I could get a resolution of 2400 x 1600 pixels by doing this (which isn't far from the 30 inch ACD's resolution of 2560 x 1600) I had to give it a go.

But when I did, I found that the picture quality was... different. When looking at text, the contrast between the black of a character and it's light background wasn't so stark and the edges of the character became fuzzier and indistinct.

So my question is: Does anyone else see this effect when they look at their display after tilting it (or their head) thru 90 degrees?
(I've got a feeling that it's something to do with the nature of our stereoscopic vision...)
_________________
Intel Mini 2.0GHz C2D (4GB/120GB/SuperDrive/10.5.8 ), 120GB WD Passport, Logitech ergo k/b
iPod Touch (32GB, 3rd gen), iPod Shuffle (512MB, 1st gen)
Back to top
View user's profile Send private message
philiparcario
Veteran Member
Veteran Member


Joined: 19 Jun 2006
Posts: 4577
Location: Howell NJ USA

PostPosted: Fri Apr 16, 2010 12:32 pm    Post subject: Reply with quote

my 24 inch screen. has a rotating pivot so I can have it as a narrow tall screen. good for viewing long email lists. I hate it the print seems wrong I don't know if it is the screen or my eyes.
_________________
2010 Mm 2.4 C2D oem 320gb hdd 8gb ram
2012Mm base 2.5 with 16gb ram diy fusion drive
2012Mm quad with 8gb ram oem 1tb hdd

promise pegasus r6 3x 3tb + 3x 4tb =21tb hdds
lacie little big disk 2x 512gb ssds
synology 2tb disk station
Back to top
View user's profile Send private message Send e-mail
JohnnyBoy
Veteran Member
Veteran Member


Joined: 13 Jul 2007
Posts: 3954
Location: West Sussex, South-East England

PostPosted: Fri Apr 16, 2010 3:37 pm    Post subject: Reply with quote

philiparcario wrote:
I hate it the print seems wrong I don't know if it is the screen or my eyes.

Ah, so it's not just me then! Smile Philip, I can't work out what's to blame. It seems illogical that the pixels should appear differently simply because they've been rotated by 90 degrees. And yet it's there to see... Confused
_________________
Intel Mini 2.0GHz C2D (4GB/120GB/SuperDrive/10.5.8 ), 120GB WD Passport, Logitech ergo k/b
iPod Touch (32GB, 3rd gen), iPod Shuffle (512MB, 1st gen)
Back to top
View user's profile Send private message
philiparcario
Veteran Member
Veteran Member


Joined: 19 Jun 2006
Posts: 4577
Location: Howell NJ USA

PostPosted: Fri Apr 16, 2010 3:40 pm    Post subject: Reply with quote

maybe the pixels are not square?
_________________
2010 Mm 2.4 C2D oem 320gb hdd 8gb ram
2012Mm base 2.5 with 16gb ram diy fusion drive
2012Mm quad with 8gb ram oem 1tb hdd

promise pegasus r6 3x 3tb + 3x 4tb =21tb hdds
lacie little big disk 2x 512gb ssds
synology 2tb disk station
Back to top
View user's profile Send private message Send e-mail
JohnnyBoy
Veteran Member
Veteran Member


Joined: 13 Jul 2007
Posts: 3954
Location: West Sussex, South-East England

PostPosted: Fri Apr 16, 2010 3:54 pm    Post subject: Reply with quote

Yes, that could be it. Perhaps that would mean that the gap between the left/right sides of the pixels is a different size to the gap between the top/bottom sides of the pixels.

Anyway, whatever the reason... I now know that it's not my eyes that are going screwy! Wink
_________________
Intel Mini 2.0GHz C2D (4GB/120GB/SuperDrive/10.5.8 ), 120GB WD Passport, Logitech ergo k/b
iPod Touch (32GB, 3rd gen), iPod Shuffle (512MB, 1st gen)
Back to top
View user's profile Send private message
MacDSmith2
Veteran Member
Veteran Member


Joined: 17 Aug 2009
Posts: 779
Location: Phoenix

PostPosted: Fri Apr 16, 2010 9:51 pm    Post subject: Reply with quote

It would surprise me if the pixels were square and not rectangle. NTSC Digital Video is rectangular pixels, 720 by 480.

"For example, LCDs typically divide each pixel horizontally into three subpixels. (When the square pixel is divided into three subpixels, each subpixel is necessarily rectangular. To make them less oblong, two subpixels per color are used, see pixels on an LCD TV.)"

http://en.wikipedia.org/wiki/Pixel

Added: "However, some imaging systems, especially those which must maintain compatibility with Standard-definition television motion pictures, define an image as a grid of rectangular pixels in which the width of the pixel is slightly different from that of its height." - same reference
_________________
Retired: Altair 8800, PET, TI 99/4A, Apple II
Mac Plus, Mac II, Mac SE/30, Quadra,
20th Anniversary Mac, iMac Purple, G4 Blue & White, iBook Clamshell
Active: Mac Mini (OCT 09) 4 GB RAM, 2.66 GHz, 500 GB HDD
Back to top
View user's profile Send private message
Smithcraft
Veteran Member
Veteran Member


Joined: 09 Nov 2008
Posts: 3246
Location: Seattle

PostPosted: Sat Apr 17, 2010 5:03 am    Post subject: Reply with quote

Perhaps since the refresh, if flat panels refresh like CRTs did, is going from side to side instead of top down, that might be causing a problem.

However, I suspect that in the engineering of the panel, it was decided that it should be designed to look best in one particular orientation. Because of this, other orientations might not have a good appearance.

Can you rotate it around so that it's upside down and try that?

SC
_________________
Grumpy old man of computing.

[Desktop] Intel mini - 2.16Ghz 2GB 60GB HDD - Newer miniStack v2 500GB - 10.5.8

[Media System] Intel i5 mini - 2.33Ghz 8GB 500GB HDD - 4 x Hitachi 2TB HDD in a qBOX-SF - 10.7.5 (Thanks Phil!)

Make sure it has pins!
Back to top
View user's profile Send private message Visit poster's website
JohnnyBoy
Veteran Member
Veteran Member


Joined: 13 Jul 2007
Posts: 3954
Location: West Sussex, South-East England

PostPosted: Sat Apr 17, 2010 11:48 am    Post subject: Reply with quote

MacDSmith2 wrote:
Added: "However, some imaging systems, especially those which must maintain compatibility with Standard-definition television motion pictures, define an image as a grid of rectangular pixels in which the width of the pixel is slightly different from that of its height." - same reference

Yeah, thanks MacDS -- that backs up Philip's hunch.

Smithcraft wrote:
Perhaps since the refresh, if flat panels refresh like CRTs did, is going from side to side instead of top down, that might be causing a problem.

You mean like a scanning cathode ray beam? Hmmm. I'm not sure that a panel behaves like that, especially with a digital (DVI) signal feed.

Smithcraft wrote:
However, I suspect that in the engineering of the panel, it was decided that it should be designed to look best in one particular orientation. Because of this, other orientations might not have a good appearance.

Yes, a design compromise is a distinct possibility; after all, if every LCD screen suffered from the same problem then the display on my iPod Touch would look better in one orientation than the other... but it looks fine both ways.

Smithcraft wrote:
Can you rotate it around so that it's upside down and try that?

Not really, no. These displays only have a 90 degree pivot. Confused
_________________
Intel Mini 2.0GHz C2D (4GB/120GB/SuperDrive/10.5.8 ), 120GB WD Passport, Logitech ergo k/b
iPod Touch (32GB, 3rd gen), iPod Shuffle (512MB, 1st gen)
Back to top
View user's profile Send private message
twitch
Member
Member


Joined: 16 Aug 2009
Posts: 53

PostPosted: Sat Apr 17, 2010 1:50 pm    Post subject: Reply with quote

Do these displays happen to be TN displays? My low cost TN display would look awful rotated into portrait mode. The more expensive IPS looks great portrait or landscape because it appears to have better viewing angle regardless of portrait/landscape
_________________
Mac Mini (mid '09) 2 ghz, 4gb ddr3, intel SSD 80gb g2, bose qc2 headphones, 24" Dell LCD 3008wfp + 2408wfp, apple wireless keybd, logitech g7 mouse, hp 2600n color laser printer; lenovo x61 tablet; Blu-ray HTPC/gaming rig win 7
Back to top
View user's profile Send private message
JohnnyBoy
Veteran Member
Veteran Member


Joined: 13 Jul 2007
Posts: 3954
Location: West Sussex, South-East England

PostPosted: Sun Apr 18, 2010 4:08 am    Post subject: Reply with quote

twitch wrote:
Do these displays happen to be TN displays? My low cost TN display would look awful rotated into portrait mode. The more expensive IPS looks great portrait or landscape because it appears to have better viewing angle regardless of portrait/landscape

I think that you might be the closest to solving this one, Twitch...
http://en.wikipedia.org/wiki/Page_orientation#Rotation_of_LCD_monitors

[Edit] Oh, wait a minute. I found a comment that links text quality to pixel orientation...
Quote:
Rotating LCD monitors is something that is maybe good for occasional use, but not something you want to do for any serious purpose.

This is because you lose the nice font anti-aliasing that ClearType and other algorithms give you. When you rotate the screen, the number of horizontal subpixels drops from 3 x monitor width to 1 x monitor width. The sharpness and clarity of text drops dramatically.

That pretty much describes what I'm seeing... Sad
_________________
Intel Mini 2.0GHz C2D (4GB/120GB/SuperDrive/10.5.8 ), 120GB WD Passport, Logitech ergo k/b
iPod Touch (32GB, 3rd gen), iPod Shuffle (512MB, 1st gen)
Back to top
View user's profile Send private message
twitch
Member
Member


Joined: 16 Aug 2009
Posts: 53

PostPosted: Tue Apr 20, 2010 1:37 pm    Post subject: Reply with quote

*font smoothing on snow leopard for non-apple displays:
opening Terminal and entering defaults -currentHost write -globalDomain AppleFontSmoothing -int 2
LINK: http://blog.jjgod.org/2009/08/18/snow-leopard-vs-dell-lcd-displays/
_________________
Mac Mini (mid '09) 2 ghz, 4gb ddr3, intel SSD 80gb g2, bose qc2 headphones, 24" Dell LCD 3008wfp + 2408wfp, apple wireless keybd, logitech g7 mouse, hp 2600n color laser printer; lenovo x61 tablet; Blu-ray HTPC/gaming rig win 7
Back to top
View user's profile Send private message
Smithcraft
Veteran Member
Veteran Member


Joined: 09 Nov 2008
Posts: 3246
Location: Seattle

PostPosted: Sat Apr 24, 2010 2:11 am    Post subject: Reply with quote

JohnnyBoy wrote:
Smithcraft wrote:
Perhaps since the refresh, if flat panels refresh like CRTs did, is going from side to side instead of top down, that might be causing a problem.

You mean like a scanning cathode ray beam? Hmmm. I'm not sure that a panel behaves like that, especially with a digital (DVI) signal feed.

Regardless of the connection type, not all of the display is sent at one time, and information is displayed as it is received.

Quote:
Smithcraft wrote:
However, I suspect that in the engineering of the panel, it was decided that it should be designed to look best in one particular orientation. Because of this, other orientations might not have a good appearance.

Yes, a design compromise is a distinct possibility; after all, if every LCD screen suffered from the same problem then the display on my iPod Touch would look better in one orientation than the other... but it looks fine both ways.

Which again presents the design criteria. A flat panel display is designed to be displayed in one orientation. Small panels used in handheld devices are designed to be used in any orientation. OLEDs are supposed to have a better display no matter what, or so I have heard. As for the iPod Touch, the display has a substainally higher resolution than most flat panel displays, which can contribute to it's display orientation properties.

As you mentioned with the subpixels, it is a design criteria for the intended use of the panel.

SC
_________________
Grumpy old man of computing.

[Desktop] Intel mini - 2.16Ghz 2GB 60GB HDD - Newer miniStack v2 500GB - 10.5.8

[Media System] Intel i5 mini - 2.33Ghz 8GB 500GB HDD - 4 x Hitachi 2TB HDD in a qBOX-SF - 10.7.5 (Thanks Phil!)

Make sure it has pins!
Back to top
View user's profile Send private message Visit poster's website
JohnnyBoy
Veteran Member
Veteran Member


Joined: 13 Jul 2007
Posts: 3954
Location: West Sussex, South-East England

PostPosted: Sat Apr 24, 2010 4:18 pm    Post subject: Reply with quote

Well, whatever the cause of the lousy picture, I'm not going to try to run these screens in portrait mode; I'm gonna achieve a 1600 pixel desktop height by buying a 30 inch screen. Cool
_________________
Intel Mini 2.0GHz C2D (4GB/120GB/SuperDrive/10.5.8 ), 120GB WD Passport, Logitech ergo k/b
iPod Touch (32GB, 3rd gen), iPod Shuffle (512MB, 1st gen)
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    123Macmini.com - Forums Forum Index -> Mac Accessories All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



      

Shop:  Apple Store  |  Refurbished Macs  |  Refurbished iPads  |  MacConnection  |  Mac Mini Vault  |  Other World Computing

MK 1 Studio Mac mini Racks  |  Crucial Mac Memory  |  Top Free Mac Apps  |  Top Paid Mac Apps



123Macmini.com is an independent publication and has not been authorized, sponsored, or approved by Apple Computer, Inc.
All logos and trademarks in this site are property of their respective owners.
Copyright © 2011 123Macmini.com. All Rights Reserved.