Loading ...TFT notion… what you should know
This guide will show you a nice and short description what TFT screens are all about. Perfect if you want to buy a new screen but you have no clue what’s it all about.
Watch out: The manufacturers have never ending innovations on what to throw on the market next.
Sadly, the prices will (in most cases) tell you about the technology used, this is why you will find monitors that are bigger, but at the same time, much cheaper than their small competitors.
I’m always hearing the word “panel”, what is actually a panel?
A panel stands for the technology used to align the pixels inside the LCD screen. It is the main factor for the pixel quality.
Dead and stuck pixels
Before you buy a screen you should ask the vendor what the return policy for dead and stuck pixels is. Some won’t even exchange it when you find 10 dead pixels.
If you ever wondered how a dead pixel (stays always black) looks like in a red, green and blue image:
And for a comparison, various stuck pixels (in color) on a red, green and blue image:
They stay always at the same position of the screen. Really scary if you ask me.
16:10 and 16:9 wide screen versus 4:3 normal screen
There is not much to say, if you got a choice you should go for a wide screen because it is much easier for the human eye to follow horizontal movements.
You can see it on the following example, what is more disturbing for your eye, watching what’s on the horizontal or vertical image?
You will require no to small eye movement to see this image.
You will notice a much higher eye movement to see the entire image.
Panel types
To simplify the big price difference, we can split all screens on the market in two categories.
Cheap, quickly evolving panels
The market mainly consists of these. They are mainly made with the so called TN (Twisted Nematic) panel. It is very cheap, but does not deliver such a good quality.
Most of these models can be found at a price under 400$.
If you go for one of these, just make sure that they entered the market not too long ago - the rule usually is: The newer the device, the better it is.
Expensive, slowly evolving panels
This is the high class of screens, those which you should buy when you are working a lot with your screen. They offer a brilliant screen quality, but sometimes a slow refresh rate.
If you want to buy one of these, make sure it’s got one of the panel names listed in the brackets:
- IPS (AS-IPS, A-TW-IPS, H-IPS, S-IPS)
- MVA (A-MVA, P-MVA, S-MVA)
- PVA (S-PVA)
These panels are mainly used for bigger screens, 20 inch and upwards. The price is mostly over 400$.
Screen refresh rate, grey-to-grey vs black-to-white
The screen refresh rate is one of the factors why many people are tempted to buy TN panel screens, unknowingly that the method used to test the value is different between TN and other panels.
While for TN panels it shows the time required to change a grey pixel tone to another grey pixel tone, for all other panels it shows the time required to switch a pixel from black to white and back to black again which consumes much more time.
So: A TN panel showing a better refresh rate than a S-IPS panel might be even actually slower.
Also, the way they measure the gray-to-gray pixel switching (used in TN panels) is not standardized, this means manufacturers can tune these values up to their liking.
Health
In general we can not say that there is a TFT screen which is more or less healthy than another.
One thing with new screens is: They are extremely bright, and very bright screens can damage your eyes. You should adapt the brightness of the screen to your room’s lights, which is usually a very low level of brightness. I set mine to 20%. Never work on your computer with lights turned off!
You should plan a break of at least 10 minutes after every hour you spend in front of the screen. During this break you should breathe some fresh air, move your body and relax your eyes.
Where should I buy?
If you don’t know where or how to buy, you can follow my guide: Intelligent buying of consumer electronics.
Credits:
- The image used for the title of this post was taken from the flickr.com user fischerhuder.
- The vertical/horizontal comparison image is made based on work from Wikipedia.
Tags: 16:9, 4:3, dead pixel, guide, stuck pixel, tft
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