What does HD and 4k are not just numbers and letters but international standards stipulated according to our ability to see and catch a bull
As stziir or paint painting in oil on canvas and stretched they use palette plate
To produce a very wide range of shades with a much smaller number of color tubes
Tv screens or computer screens the colors are fewer even than most artists
Using the three primary colors are sufficient to cause the human eye to have 16 million colors and more.
Unlike the painters draw freely all over the canvas display instruments building
The image of arranged across a crowded network such as a huge table of chocolate. The dots
Called pixels light pizzas anywhere on the table and turn on or off can build their image
Each pixel is made of three different light sources. Each of these lights in one of the basic colors
Red, Green or blue and anyone can shine in one of 256 levels of brightness. Therefore each pixel
Three sources can shine in one of 256x256x256 different combinations that is more
16 million options. All such illumination option taken in the eye by special cells feel
Published in various colors and dochim brain translated as one color
How does an image on screen
Why screens display images in this way is that it's probably one of the simplest methods
And to achieve the goal. The problem is easy to draw straight lines from a table of points,
Like the blue or yellow line. But diagonal lines like "broken gray line
The stairs. Curved line suffers from the same disturbing staircase effect.
In the table of grey diagonal line appears broken as opposed to straight lines
To produce better screens can increase the density of points i.e. assume small dots
More and more the same. OPS. It's harder to see the steps create
Gray line or using various required a big effort at to do so. the more you crowd
The points that you get a smoother line. This is an illusion caused
by the limited ability of the eye to distinguish fine details
When the dots are very small and also very many diagonal line appears smoother
How dense the points should
The human eye is a sophisticated and gorgeous. She has high sensitivity to color it can
To operate even when there is plenty of light in the environment and there is little and it pictures pretty fast
But like every eye camera has the ability to see small details. This limit is called
Separation capability of the eye
The border size of the details that we can discern varies from person to person because of small differences
The structure of the eye and vision problems. The limit also depends on the space where the observer but as a rule of thumb
People can observe details that are about a tenth of a millimeter at a distance of half a meter. This means
If the dots on a screen smaller than one-tenth of a millimeter, and we sit at a distance of two feet
The screen our eye cannot distinguish between two adjacent pixels
As it is impossible to distinguish between not seeing the effect bothers-manage
To deceive the eye and produce a smooth image. Once the congestion costs above the separation
There's no point eye to loosen the points because the receive will not be better.
This is one of the important differences between the display pixel density technology. As congestion.
This high Visual eye smoother because the separated or set points by a large number of points (and not Smooth in the real).
This means the display technology of HD is the High Definition and high-resolution UHD
He particularly high-resolution Ultra High Definition. It was agreed there that he decided the International Union places like Telecommunications One of the international standardization bodies to facilitate
For consumers to understand what is (more or less) the display quality of a device they buy
How dense the points for devices sold today.
Currently in standard defined two generations UHD agree 4k and 8k. There are 4 screens
Columns and rows that are approximately 2160 4000 columns that give the screen K marks
"Kilo"meaning a thousand like kilogram or kilometer. 8 screens make us in a few years.
Decide whether to spend thousands of dollars on new tv 7680 columns and rows 4320
Screen size is measured diagonally between the two corners. The width of a 50 inch UHD
Is about 110 cm and 62 cm in height approximately. The size of each pixel on the screen is approximately
Millimeters (3 millionth of a millimeter). This means that if you are sitting or standing at a distance of half a meter,
The pixel size is one-third of the border separation capability of the eye so we don't notice all the pixels on the screen and the picture will look very smooth
It is interesting to compare to legacy HD and UHD standard. The screens were much less
Pixels. For example, in an HD screen with 1080 lines, the pixel size is about half of the eye's separation limit and not a third
It is still below the separation boundary of the eye and therefore a smooth image is obtained but if the screen
Was greater for instance 70-inch screen pixel is already too large. UHD important facility.
Especially for very large screens or sitting very close to the screen
Interlaced or progressive
Until here we focused on one main difference between the display technologies and super-density pixels. But there are many other differences that exist.
UHD that cost thousands of dollars and UHD TVs of the same size that cost tens of thousands of dollars and more.
One of the reasons for this difference is the refresh rate of the screen. This is the rate at which the TV re-draws the picture, and here as the higher the tempo, the smoother the picture, especially when you watch content that has a lot of movement like sports events.
Different TVs refresh the image at a rate of 60 to 120 times per second. In the older HD method, screens were characterized not only by number but also by the letters p or i. For example, there were 1080i and 1080p screens, and the picture on p screens was better. These letters marked the words interlaced and progressive.
The idea is this: the screen should redraw the image 60 times per second. The more lines on the screen, the faster you have to paint them, and it can be difficult. To cope with the difficulty, manufacturers began to use an interesting method in which one refresh cycle draws the double lines of the image and the next cycle draws the odd rows, and the brain joins all the lines into one picture. This method is called an interlacing that breaks, or joins lines together. As long as it happens fast enough it's a plausible solution, but some people have noticed the flicker of the screen. In the other, more advanced method, marked by the letter p, all lines are drawn simultaneously. In the UHD standard, all the screens draw the image using the progressive method.
Other differences between screens relate to the different ways in which pixels are illuminated and the screen's ability to completely turn off pixels, that is, how good the black color the screen displays. Most of these details, and others not mentioned, are not differences between display standards, but rather differences between different display technologies and production methods of screens.