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TFT against CRT

lrn

New member
Hello friends,


What's your opinion of TFT-monitors in comparison with CRT for CAD-CAM work? Would you exchange 19'' CRT professional monitor for 17'' TFT high class too? Thank you in advance!
 

ndk

New member
To me, for CAD-CAM work, TFT is most suitable. where really-world colors is not very important. As you know,TFT is great for you health and also your eyes.


But in graphic situation like corel or photoshop,TFT is not on the same street as CRT(up to now)!CRT with true, real-world colors must be your choice!


Hope this helpful
 

xcad

Member
It depends on the hours you spend on a monitor. If you work >8 hours a day go to a TFT selection, regardless of lower performance (resolution, lightness), because i don't think that TFT today can reach the performance and lightness of a CRT monitor.


CRT monitors "carries" a lot of years of development and matureness.


I suggest you to buy a TFT monitor, but to be very carefull that this monitor can work with an upper of 1600X1200 resolution with safety. If you can not affort the money then go to a CRT (IYAMA, EIZO, SONY) monitor that can work up to these resolution with a affordable refresh rate (>100Hz)
 

lrn

New member
Thank you!


My opinion is the same, as far some time work over 8 hours, so that TFT-monitor will be most suitable.
 

Uros

New member
I do not agree, that CRT is better for rendering. I use TFT (HP 2035) with DVI cable and to my opinnion colors can be compared to CRT or even better. Not to say, that at CRT monitor it can happen, that brightness and contrast are different every time you turn monitor on. With TFT colors are constant.
 

AHA-D

New member
Due to my dual input Iiyama 22" CRT dying under my hands 2 weeks ago I had a chance of comparing the two. (Setup is 2 computers - one allround and one CAD-specific both connected to the same screen - where I switch monitor input and keyboard to work on either one).


I've worked for years on CRT, all day at the job site and anything between 2 and 6 hours at night for private business, without eye trouble. Prerequisite for this isimage quality. This is both the monitor itself - should be top quality, sharp, stableandclear allover - and the video card being able to deliver high resolution at high refresh rates.


At present I work a 17" TFT alongside a 19"CRT, both delivering about the same real viewing surface.


What bothers me in the TFT is how it handles fine details. Characters on the screen are not identical, depending on the amount of pixels they get to be displayed. The same goes for thin lines : some get one pixel, some get two, some just disappear between two screen pixels. This is due to the difference in technology. On a CRT a pixel just sits there, waiting for the electron beam to activate it (all or partly). Since it's only a reactive surface any part of it can emit light, meaning the bottom half can be lit while the top half is dark. A TFT pixel works on an all or nothing base. It gets instructed a certain transparency level and then all of the surface is set to this level. This explains why TFT only works fine on native screen resolution while CRT accepts any resolution, even higher than available through the actual dot pitch.


How this technology difference translates in real life ? Takea thin vertical line, one pixel wide, situated in the middle between two pixels. On a CRT this line will actually try to hit the middle causing screen dots going dark to light from left to right and vice versa. A TFT will turn both pixels left and right to half brightness because each gets half a line to display.


The other thing is viewing angle. I'm sitting rather close to the screen and notice quite some difference in appearance depending on where on the screen I'm looking. Lines at the bottom even tend to get a kind of 'reverse video' effect. But this can be due to the TFT-quality, maybe it's a limited viewing angle type.


Anyway I ordered a new CRT, until TFT gets to an acceptable level (quality and pricewise).


So regarding the original question. I would certainly not go for a 17" inch since it's just too small for a decent resolution (you'll get 1280x1024 max). And if the option 19" TFT is open I'd rather spend the money on a 22" CRT. I regard 1600x1200 resolution necessary for comfortable working.


Alex
Edited by: AHA-D
 

Uros

New member
AHA-D, do you use DVI cable on TFT?


TFT is digital display, CRT is analog. So, when plain VGA connection is used, graphic card first converts the signal from digital to analog (which can be displayed on CRT) and then TFT monitor converts the signal back to digital. Here are two unnessecary conversions, resulting in errors like AHA-D has described.


According to my experiance, use of DVI connection can eliminate those errors.
 

AHA-D

New member
Uros,


The TFT only had a standard VGA-cable present, which may indeed acount for some loss of quality. Depending on the model some TFT's adapt automatically to the phase of the video signal, some only offer manual adjusting (phase shifting results in vertical wave patterns on the screen).


DVI is not necessarily a digital transmission, the same basic connector (and connector name ! ) is used for all versions, which include analog, digital and mixed.


I haven't seen any color shifting on my monitors (as long as I keep strong magnets away). If you did I suppose it's a quality or age issue. Not all TFT are equally backlit either.


Alex
 

Uros

New member
when I was using analog transmition (VGA cable) I have seen quite noticable moire efect in some cases (for example, in ProE, when a feature is redefined, it is dimmed). The problem was gone, when I switched to DVI-digital signal.
 

dr_gallup

Moderator
I use a Sony 24" CRT but our two newest workstations have Dell 2405FPW 24" LCD monitors using the DVI connection. Nobody complains about the Dell 2405FPW. Big is beautiful for Pro/E.
 

AHA-D

New member
Big is beautiful in any "graphic" program. That's why the interface area should be as lean as possible. I remember days on Microstation where you needed a 4 window setup to work comfortably in 3D and therewere more buttons and toolbars cluttering the screen than pages in a phone book, making you feel like modelling through a keyhole.


It's always a pity when 500 $ of your screen is taken by little used items or worse even : empty space.


Alex
 

AHA-D

New member
Got my new Iiyama 22" CRT delivered (old one has gone "narrowband" picture, my brother is looking into it - probably only a burned out capacitor - but I didn't want to wait and work 19" replacement). Great image quality and only 20 Euro/kg. And it's protected against theft. Thieveswill berecognisable having severe spine injuries ...


Alex
 

Moroso

New member
Don't forget about having a good refresh rate (16 ms or lowerer) so you don't get the ghosting when using Pro/E


DVI cable is a must vs the analog signal.
 

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