Re: LCDs for HA (was Re: FS: (18) LCD . . . )

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Lewis Gardner" <lgardner@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:46d24e33$0$26705$d94e5ade@xxxxxxxxxxxxxxxxx
> Robert Green wrote:
>
> > What I dislike the most about LCD panels is that the
> > angle of view almost never equals that of a good CRT.
>
> Take off your polarized sunglasses!
>
> Seriously, I have installed lots of LCD computer and video monitors and
> the viewing angle is on par with CRTs for all but the oldest and
> cheapest models. The widescreen Dell I am using right now is readable
> for almost 180 degrees on both axes.

"Readable" is a very subjective word.  I've looked at a lot of different
monitors and TVs since this posts try get a feel for the problem.  While
LCDs are indeed much more readable at an angle than they once were (my
Fujitsu and Compaq PC screens, the best quality there was at the time, were
unreadable when about 45% off-axis.  Any one of the newer LCD's I have, both
cheap and mid-range, can do far better than that.  While 180 degree viewing
is a physical impossibility, a rough eyeballing with a plastic
protractor and a "sight tube" made out of PVC pipe (where's sextant when you
*really* need one?)  you can still make out the characters at about 150
degrees.  At least *I* can.  That's remarkable considering the Fujitsu, as
beautiful as useful as it is can't be mounted on a wall and then read easily
from a nearby sitting position.

But there's a catch to the wider viewing angles of the newer, supertwisted
LC displays.  The differing ways the pixels are created causes LCD to have
much more of a "sweet spot" than equivalently sized CRT's.  As the viewing
angle increases, the light falloff on an LCD is quite a bit more dramatic
than a CRT.  I find nowhere near the same falloff on CRT's because with my
bad visions the reduction in brightness lowers contrast as well and often
causes normal room light to wash out the image when viewed at an angle.  I
work with multiple monitors and now that I've been replacing 3 monitor
"clusters" with one or more LCD monitors I find myself adjusting monitors
far more often than I ever did with CRT's.

As I was trying to photograph the Windows 2000P login screen to show how the
problem still exists, I noticed that the there's substantially less light
reaching the lens/eye as soon as you go off-center.   As I varied the angle
between the screen and the camera, my camera, which displays and records
F/stop and shutter speed, captured the this information in each photo and
showed substantial difference between on and off axis viewing.  The image is
indeed readable at far greater angles than 5 year old screens using older
technology.  But the considerable difference in the way the pixels are
illuminated does make a difference in the screen readability from off-axis.

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

The CRT image is created by phosphorescence from an electron beam.  The
image is displayed behind a layer of hard, optical quality glass that's not
likely to yellow over time. On the other hand, the LCD display is created by
filtering light from our old friend, the compact fluorescent light bulb. The
light is than filtered through layers of plastic and liquid crystal
material.  Maybe the new displays are better, but on lots of LCD panels I've
seen, the CF bulbs cause very visible blotches and hotspots,. especially on
a big, mostly white screen.  I am sure that will improve with time, but on
my test bench, the CRT will be returning.  The main reason is that LCDs mean
I have to stoop or pull up a chair and sit just to log in to Windows.  I
didn't have to do that with a CRT in the same position.

Try reading the WIN2K login dialog box on an LCD display from a very high
upward angle and report back.  While I agree that most new LCD panels are a
lot better than they were, dialog boxes that use high-lighting and other
display attributes can render the most critical piece of information on the
screen unreadable.  I noticed this "feature" since cracking my ribs.  It's
painful for me to have to sit just to log on to a desktop computer, so I am
aware that with LCDs I find it necessary to sit or adjust the screen angle
just to type in my password accurately.

There was an article on the viewing angle issue just this month:

http://www.newscientist.com/article.ns?id=dn12425&feedId=online-news_rss20

**********************************************************
Screen swivels its crystals for a better view
12:53 06 August 2007
NewScientist.com news service
by Tom Simonite

The Taiwanese researchers have developed a prototype display connected to a
miniature camera that tracks the location of a viewer. Software then
calculates how to adjust the liquid crystals within the display to produce
the clearest possible image.  "Viewing angle is an inherent, fundamental
problem for the LCD because of its working principle," says Wayne Cheng, who
developed the screen with colleague Chih-Nan Wu at the Photonics and Display
Institute, National Chiao Tung University in Taiwan.

**********************************************************

Why would anyway undertake such an effort if there wasn't nearly universal
acknowledgement that LCDs have viewing angle problems?

My point in bringing that up I'm just reminding people to be cautious about
buying an LCD monitor of unknown age and design that they can't really
inspect before buying.  Especially not from someone who really shouldn't be
advertising commercially in a COMP hierarchy newsgroup anyway.  A simple
Google search revealed (428,000) hits about the viewing angle problem, many
of them quite current:

http://www.google.com/search?q=LCD+monitors+angle+of+view+compared+to+CRTs

All About Monitors: CRT Vs. LCDA CRT monitor can be viewed from almost any
angle, but with an LCD this is often a problem. When you use an LCD, your
view changes as you move different ...
www.webopedia.com/DidYouKnow/Hardware_Software/2005/all_about_monitors.asp -
80k - Cached - Similar pages

TalkBack: LCD vs crt review | reader response on| CNET News.comAngle of
view: Although the CRT monitors lead the way in this department, the viewing
angle on LCD monitors is getting wider and wider and current models ...
news.com.com/5208-1041_3-0.html?forumID=1&threadID=3505&messageID=19541&star
t=-1 - 46k - Cached - Similar pages

CRT vs LCD Monitor Comparison GuideUnlike those clunky CRT monitors, LCD
displays usually weigh in under 10 ... and size are the LCD's big advantage;
now here's the tricky parts: view angle, ...
www.techimo.com/articles/index.pl?photo=202 - 74k - Cached - Similar pages

Google Answers: CRT VS LCD Monitors/Health Risks VS Image QualityCon: -While
graphics colors are very sharp, the angle of view the graphics .... Eye-One
Display from Gretag Macbeth, is intended for CRT or LCD monitors. ...
local.google.com/answers/threadview?id=318068 - 27k - Cached - Similar pages

Digital Darkroom Forum: CRT vs LCD for Digital Darkroom - photo.netAny
thought on the pros and cons of CRT vs LCD monitors for editing color photos
... Yup, they are horribly fussy about the angle you view them at. ...
photo.net/bboard/q-and-a-fetch-msg?msg_id=00FZPu - 21k - Cached - Similar
pages

LCD TV Buying Guide: flat screen tv ordering FAQ & TipsUnlike CRTs, LCD
monitors have only one optimal resolution. ... One of the main disadvantages
of LCDs when compared to CRTs is their limited viewing angle. ...
www.lcdtvbuyingguide.com/lcdtv-crt.shtml - 24k - Cached - Similar pages

Web Design - The Complete Reference: Chapter 13: Color - Monitor ...Monitor
Types: CRT vs. LCD. Most desktop computer monitors are CRT ... The most
important color issue for LCD monitors has to do with the angle of view. ...
www.webdesignref.com/chapters/13/ch13-14.htm - 11k - Cached - Similar pages

Monitor DetailsAngle of view: Currently CRT monitors are the leaders in this
area. However, LCD screens are improving all the time. Viewing angle is
usually not a major ...
www.dmcunlimited.com/index_files/monitors.htm - 75k - Cached - Similar pages

Comparison: Sony SDM-N50, Samsung SyncMaster 570S and IBM T85A LCD ...If
you're running business software, the view angle sensitivity is unimportant.
.... It's still light compared with CRT monitors - and very light compared
...
www.dansdata.com/flatscreens.htm - 40k - Cached - Similar pages

Liquid crystal display - Wikipedia, the free encyclopediaLCD panels tend to
have a limited viewing angle relative to CRT and plasma displays. This can
reduce the number of people able to conveniently view the same ...
en.wikipedia.org/wiki/Liquid_crystal_display - 80k - Cached - Similar pages

With so many people experiencing the problem and designers working on ways
to automatically adjust the displays to optimize LCD viewing angles I'll
stand by my contention that LCDs aren't equivalent in viewing angle to CRTs,
at least not when it comes to the light falloff that occurs when LCDs are
viewed at anything other than perfectly perpendicular to the viewer's plane
of vision.

--
Bobby G.