LCDs cause measurably less eye strain than CRTs - for a couple of reasons:
Most CRTs are 'multi-synch' - which means that they can draw different
numbers of horizontal lines based on the synchronization signal from the
card. On Trinitron tubes, synch rates below the design target of the
monitor result in faint horizontal lines - which aren't that bad.
On all other color monitors which use a shadow mask, you get misalignment
from the electron gun on the shadow mask at all but the design synch rate.
The result is that all monitors (trinitron included) get 'fuzzy pixels'
above their designed synch rate, and all but Trinitron's get fuzzy below
their design synch rate.
This fuzziness results in eye strain because letters are harder to read and
require more careful focussing.
A second factor is caused by the 'dwell' or 'retrace' cycle. Especially
when reading text - less so in image processing. The intermediate and above
reader, does not 'sound out' words. Instead we 'chunk them, whole words at
a time and prescan between 5-15 letters ahead. And our eyes (western) scan
left to right. Problem is that when the dwell phase comes through, the
darkness causes us to lose the word we were in the middle of scanning. This
causes our eyes to have to come to a screeching halt, reverse direction,
scan backwards, reverse direction again and scan forwards. Also causing eye
strain.
Note that the above effect also occurs when reading paper text by
flourescent lighting, and flourescent lighting in combination with CRT
monitors exacerbates the problem by causing higher rate 'beat frequencies'
LCDs do not have this problem. In part because the scan rate of LCDs is in
the Hundreds of hertz (its necessary to get gray scale variation), and
typically a single high resolution (1024x768 or higher) LCD monitor will
have rescanning going on in multiple sub-panels. Also LCDs typically rescan
on the vertical axis - one that the human eye is less sensitive to. As a
result, you don't get the dwell cycle problem.
Also pixels on LCDs are fixed in size. LCDs get 'multi-synch' capabilities
by interpolating the signal and either adding or subtracting pixels when the
signal is outside the designed synch rate.
That said, LCDs typically are very poor for image processing because
1) their color balance isn't as accurate as a CRTs
2) their max contrast ratio isn't as high as a CRTs (I can go into why if
you want)
3) they cannot get as dark a black as a CRT
4) their color gamut isn't as broad as a CRTs
And the lower the price of the LCD, the worse the problem.
----- Original Message -----
From: "Laurie Solomon" <laurie@advancenet.net>
To: <karlsch@earthlink.net>
Sent: Monday, October 21, 2002 2:04 PM
Subject: [filmscanners] RE: Digital Darkroom Computer Builders?
>I hear that they still cannot be taken seriously as far as colour accuracy
and profiling
That is what I hear also. I also find that unless one views the screens at
a given angle, they tend to be hard to see clearly; but this could also be
my eyes. :-)
>I like the idea of LCD's
>being less painful on the eyes (on long work sessions)
Where did you hear that? It may be your ecxperience and that of others; but
it has not been mine, although to be sure I have not had that much
experience with LCDs.
Aside from these factors, I am not sure that I can elaborate.
-----Original Message-----
From: filmscanners_owner@halftone.co.uk
[mailto:filmscanners_owner@halftone.co.uk]On Behalf Of David Townend
Sent: Monday, October 21, 2002 1:34 PM
To: laurie@advancenet.net
Subject: [filmscanners] Re: Digital Darkroom Computer Builders?
Hi Laurie,
I'm in the middle of updating my system and am following this thread with
interest... Re : CRT verses LCD. Can you elaborate on why you prefer CRT's ?
It may help with my decision on which way to jump. I like the idea of LCD's
being less painful on the eyes (on long work sessions), but I hear that they
still cannot be taken seriously as far as colour accuracy and profiling
go's. Is this still the case ?
Thanks.
>From David
--
You can view David's on-line folio at
and also the results of a recent job at
T - 00 44 (0)20 8374 6289
M - 00 44 (0)7770 622144
> From: "Laurie Solomon" <laurie@advancenet.net>
> Reply-To: filmscanners@halftone.co.uk
> Date: Mon, 21 Oct 2002 12:40:50 -0500
> To: d.townend@ntlworld.com
> Subject: [filmscanners] RE: Digital Darkroom Computer Builders?
>
> I personally would
> prefer two 21 inch CRT monitors or a single 21 inch CRT monitor and a 17
CRT
> inch monitor for the palettes to a single LCD monitor of any size or a CRT
> monitor bigger than 21 inches.
----------------------------------------------------------------------------
------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title
or body
----------------------------------------------------------------------------
------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title
or body
----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or
body
