What is Contrast Ratio?

Contrast ratio is used to define the difference between the maximum and minimum brightness of a display. It’s the difference between the whitest white and the blackest black a screen can produce. For example, a contrast ratio of 1000:1 means that the white is 1000 times more brighter than the black.

So what this means is that the higher the contrast ratio the better because a higher contrast ratio allows more darker blacks to be produced next to whites, which results in making the picture more realistic.

Contrast ratio can be measured by using a black and white check pattern as shown below .

What does the contrast ratio depend on?

Contrast ratios depend greatly on the type of display you are using.

LED-lit displays shine light through a TFT (thin-film-transistor) layer in order to produce an image. When producing blacks, LED displays block out light as much as possible but this only manages to produce washed-out greys instead of pure blacks or in some cases light might pass through the blockade resulting in poor uniformity.

On the other hand, displays like OLED’s can theoretically achieve infinite contrast ratio, which means OLED can produce pure blacks right besides white. This is because the pixels in OLED displays can be completely switched off meaning that they produce no light and thus achieve pure blacks.

However it should be kept in mind that the human eye’s ability to distinguish between detail and contrast is very restricted so two displays with different contrast ratios might seem similar to the average viewer.

Difference between static and dynamic contrast ratio

Dynamic contrast ratio is the brightness ratio between the brightest and darkest shade the device can produce, whereas static contrast ratio is the difference between the blacks and whites a monitor can produce while the backlight is still powered on, so because of this static contrast ratio can be called a more realistic measurement of a device’s contrast ratio.

LED backlit monitors have the ability to power off the backlight in some areas of the screen resulting in a pure black area, which can lead to the dynamic contrast ratio being measured at over 50,000,000:1. On the other hand, the highest static contrast ratio that can be achieved is only limited to 3000:1 as in order to measure the static contrast ratio, the backlight has to remain powered on.

How to know what contrast ratio would best suit your needs?

The right contrast ratio depends on the intended use of the display.

If you intend on using the device inside in a dark environment, then a higher contrast ratio would provide the best experience. On the other hand, if you intend on using the device in an environment with ambient light then a lower contrast ratio would be optimal for your experience.