| Topic: |
Science > Physics |
| User: |
"TonyJeffs" |
| Date: |
02 Dec 2003 07:55:00 AM |
| Object: |
Difference in light between tft and crt monitors |
I find TFT monitors painful to use - can't use em -, as opposed to
Cathode Ray Tube monitors;
But what could be the significant difference?
Contrast? TFT are quoted as having a better contrast (therefore better
dynamic range? presumably?"
Brightness?
Flicker?
Infra red, or uv emissions? - presumably tft is better if anything in
this regard.
Colour? Perhaps the colors are slightly different due to the materials
used, but can't see that being an issue?
- I can't think of anything else...
So what could be the relevant difference?
Tony
.
|
|
| User: "EL" |
|
| Title: Re: Difference in light between tft and crt monitors |
03 Dec 2003 04:45:30 AM |
|
|
(TonyJeffs) wrote in message news:<8ec4c623.0312020555.511d47bf@posting.google.com>...
I find TFT monitors painful to use - can't use em -, as opposed to
Cathode Ray Tube monitors;
But what could be the significant difference?
Contrast? TFT are quoted as having a better contrast (therefore better
dynamic range? presumably?"
Brightness?
Flicker?
Infra red, or uv emissions? - presumably tft is better if anything in
this regard.
Colour? Perhaps the colors are slightly different due to the materials
used, but can't see that being an issue?
- I can't think of anything else...
So what could be the relevant difference?
Tony
[EL]
Psychological.
EL
.
|
|
|
| User: "TonyJeffs" |
|
| Title: Re: Difference in light between tft and crt monitors |
04 Dec 2003 08:18:49 AM |
|
|
(EL) wrote in message news:<7563cb80.0312030245.5b8f9b43@posting.google.com>...
So what could be the relevant difference?
Tony
[EL]
Psychological.
EL
Darn ;-)
Good answer, but how can I prove it's not?
I have an eye condition, which gets very slowly worse, and I know when
it's getting worse because it's more painful.
I've been working with TFT for a painful 2 months, and there's
definitely a difference.
But I can't prove that to you or my bosses.
I guess I could do a controlled trial with before and after retinal
images before and after prolonged exposure to a)CRT and b)TFT.
Anyhow, here's a perfect straight line!
_________
___________________________________________/ |________
...............
Thanks too Professor for all the detail, but still nothing that really
explains the problems I have with TFT.
Tony
.
|
|
|
| User: "Tony" |
|
| Title: Re: Difference in light between tft and crt monitors |
05 Dec 2003 09:35:06 AM |
|
|
(TonyJeffs) wrote in message news:<8ec4c623.0312040618.8e8dc4e@posting.google.com>...
Good answer, but how can I prove it's not?
I have an eye condition, which gets very slowly worse, and I know when
it's getting worse because it's more painful.
I've been working with TFT for a painful 2 months, and there's
definitely a difference.
<snip>
Thanks too Professor for all the detail, but still nothing that really
explains the problems I have with TFT.
I just checked out some flat panel displays, all have a
refresh rate of 60 Hz. Yikes!!! I do not know what is
claimed for TFT stuff, but a CRT at 60 Hz. is *big*
trouble. This goes back to the days of EGA graphics and
IBM PS2 computers. But the problem was by no means restricted
to IBM monitors. The 60 Hz. flicker from the monitor would
beat against the 60 Hz. flicker from fluorescent lighting
and *everybody* would get eyestrain and headaches. About
the only thing that could be done was to turn off as
many fluorescent lights as possible, which had only a
modest effect. 70 and 72 Hz. monitors got real popular
real fast because of this. It was horrible.
Just looking at flat panels in the stores hurts my
eyes, so I can't imagine working on one. I feel like
I "Been there, Done that" with this issue. Big CRTs are
cheaper than flat panels and have a better image, so
get one and make room for it.
Cheers,
Tony.
.
|
|
|
| User: "TonyJeffs" |
|
| Title: Re: Difference in light between tft and crt monitors |
06 Dec 2003 04:59:08 AM |
|
|
Hi The other Tony,
That's an interesting thought about the interaction between monitor
refresh and fluorescant light refresh.
I think it is less of an issue with TFTs since they have sustain,
where the pixel doesn't fade out,, like a conventional light bulb, so
the flicker isn't apparant.
Detector, no it isnt a notebook, although I do have one that I never
use. Toshiba notebook -doesnt have brightness contrast adjustment!!!
Cheers
TonyJeffs
.
|
|
|
|
|
| User: "Detector195" |
|
| Title: Re: Difference in light between tft and crt monitors |
04 Dec 2003 08:30:34 PM |
|
|
(TonyJeffs) wrote in message news:<8ec4c623.0312040618.8e8dc4e@posting.google.com>...
hemetis@hotmail.com (EL) wrote in message news:<7563cb80.0312030245.5b8f9b43@posting.google.com>...
So what could be the relevant difference?
Tony
[EL]
Psychological.
EL
Darn ;-)
Good answer, but how can I prove it's not?
I have an eye condition, which gets very slowly worse, and I know when
it's getting worse because it's more painful.
I've been working with TFT for a painful 2 months, and there's
definitely a difference.
But I can't prove that to you or my bosses.
I guess I could do a controlled trial with before and after retinal
images before and after prolonged exposure to a)CRT and b)TFT.
Anyhow, here's a perfect straight line!
_________
___________________________________________/ |________
..............
Thanks too Professor for all the detail, but still nothing that really
explains the problems I have with TFT.
Tony
I sympathize, since I get eyeball headaches from computer use.
Is the TFT attached to a notebook computer? My only reason for asking
is that your screen may be too damn close. Or it may be too low down,
so you are stooping down to see it.
Maybe your eyeballs are getting older, your workload has changed,
office environment, lighting conditions, etc.
One thing to do (regardless of CRT or TFT) is make sure you are not
staring at the screen for extended periods. Train yourself to look
away whenever you don't need to be looking at the screen.
You have a legal and ethical right to a safe workplace, and you should
not have to prove anything.
.
|
|
|
|
|
|
| User: "Jan Panteltje" |
|
| Title: Re: Difference in light between tft and crt monitors |
02 Dec 2003 11:00:10 AM |
|
|
On a sunny day (2 Dec 2003 05:55:00 -0800) it happened
(TonyJeffs) wrote in <8ec4c623.0312020555.511d47bf@posting.google.com>:
I find TFT monitors painful to use - can't use em -, as opposed to
Cathode Ray Tube monitors;
But what could be the significant difference?
There are a few important differences:
TFT has better geometry then CRT (the pixels are aligned neatly in lines
so no geometric distortion of pictures is possible).
TFT is more flat then CRT (depth of set).
TFT uses perhaps less power then CRT.
TFT has less electromagnetic radiation the CRT (from the deflection system).
TFT has no very high 25kV voltage supply.
Now thats about all of the pros, maybe I forgot something.
Now the contra arguments:
TFT is more expensive then CRT
TFT (all the ones I have seen) have lousy gamma.
Gamma is this:
In a normal CRT the brightness / drive voltage relation is 1 to the power 2.2
In the cameras this is compensated for by an opposite correction.
In TFT manufacturers seems to have big problems with achieving the 2.2
This causes black areas to become less detailed and sometimes white areas
to have incorrect grades of brightness.
This is really bad (looks horrible on movie material).
TFT does NOT have higher brightness then CRT.
TFT does NOT have higher contrast ratio then CRT.
TFT may have (with backlight) very un-even distribution of white,
for example in LCD projectors if you put a 70% white screen, it will be
brighter in the middle then on the sites.
TFT does NOT have higher resolution then (a good) CRT.
TFT does NOT have a higher lifetime then CRT, for example defective pixels
can show up in the middle of the screen, and that is really a no no for hight
quality TV use, I already get nervous about specks of dust on my screen, one
defective pixel would be a throw away issue, this will certainly count in a
TV studio monitor.
TFT are sometimes too slow for use in live video.
As to the flicker maybe TFT has no flicker, but what use is it if it is to
slow.
Color can be quite good, but not as vivid (now I am subjective) as CRT.
If the colors are different then the one used in the camera / encoding matrix
specification, the colors will be simply WRONG.
When selecting a monitor / TV, the PRIME objective is a good picture.
TFT / LCD is NOT ready for prime time TV.
Get a plasma display if you MUST be flat, and have money to burn.
CRT and plasma have large viewing angle, high brightness.
Plasma has short life time.
Projectors (LCD) are very expensive because of the cost of replacement bulbs..
Sales talk, new product, worse then the old, LCD TV, wait a couple of years...
Maybe 20.
There are other techniques being developed, polymers, oil drops on paper,
what not.
Brain implants too...
Oled display...
I am watching this on a Samsun SyncMaster 950p monitor (with CRT).
This one is great for video too.
If a better TFT screen with a better picture then this is ever made, yes
then it would be time to switch.
Now, if you want a TV buy a nice one for 500 $ with a CRT.
It will save you 4000$ over the big LCD or Plasma, and unless you can
make that money back by renting out the little room space you saved, this
is not only the better, longer lived, brighter, cheaper, faster etc...
solution, but you can go on holiday from the 4000 'saved' and who knows
who you will meet, well that is another story altogether.
Professor Panteltje
.
|
|
|
|
|
Related Articles |
|
|
