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When buying a new TV you may encounter poor color uniformity on a black background, also known as the “Dirty Screen Effect” or DSE for short. So what causes this, and can you do something about it?
What is Dirty Screen Effect?
Dirty screen effect refers to the uneven appearance of a solid color, especially a gray, black or white background, on a display panel. It can affect anything from TVs and monitors to smartphones and laptops with thin and modern displays. The effect is so named because it looks like an opacity on the display under the right conditions, such as a screen that needs to be cleaned.
You can try the dirty screen effect on your TV by using full-screen solid colors. Under normal viewing conditions, you can only see the effect in very dark or very light scenes. It can only be visible in a very dark room. Sometimes movement such as the camera pan (especially on solid colors, such as the green pitch of a sports game) can make the effect stand out.
@SamsungUK Can you please tell me how this vertical banding/nasty screen effect defect is within your product specification framework?! I’m pretty sure you won’t be using these images to promote your 2021 QLED range. Image movement on my TV (like camera pan) is even worse! pic.twitter.com/lmC9pQYFo2
Matt Francombe (@FrancombeMatt) 3 October 2021
DSE mostly affects LED-lit LCD panels but effects similar to DSE can also appear on OLED displays. On LCD screens this is caused by manufacturing issues with the panel or by uneven backlighting. In some cases, you can see a grid of LED backlights on the back of a set that uses full-array local dimming.
The effect on OLEDs reflects either a faulty panel or banding that often keeps its head on black material. Taking a picture of your display with a smartphone will almost always enhance the effect compared to a real-world viewing situation.
You may have heard the term “panel lottery” used to describe the purchase of a new TV. If your set displays signs of DSE, the “good” news is that very few panels look correct when examined on a full-field gray, white, black, or even color slide.
What can you do about it?
Before you run to test the uniformity of your TV’s panel, consider this: If you can’t see any variation in real-world viewing conditions, your panel is probably good enough. Many TV owners don’t notice a problem until they go looking for it, at which point they notice flaws or problem areas that are hard to ignore. Same is the case with OLED sets with banding and dark patches.
If you have to test every aspect of your TV, do it the first time you buy it so you can claim the warranty right away. In the case of OLED, you may be asked to “run it” for a few hundred hours or run a pixel refresher cycle on it to reduce banding issues before your request is honored.
There is nothing you can do to reduce the presence of DSE on the LCD as the problem is down to manufacturing. Websites like RTINGS test each set for occurrence and post their findings online, but there can be differences between different products of the same model, which were produced in the same factory in the same year. It’s a panel lottery!
new tv review, @samsungs Q900/Q900R 8k QLED. An excellent 8k TV with impressive picture quality. It has wide viewing angles, but in contrast is similar to the Sony Z9F. Unfortunately, there are a lot of nasty screen effects worth noting. pic.twitter.com/ENlJq31qQz
RTINGS.com (@rtingsdotcom) March 27, 2019
If in test conditions your TV displays some DSE or your OLED has visible banding, try to get it out of your mind. If you don’t pay attention to it, you can easily ignore it and not pay attention while watching movies, streaming TV shows, or even playing games.
If it really bothers you and your TV’s warranty has expired – well, there’s always a new TV to buy. Of course, you’ll take another spin in the panel lottery.
Buying a new TV?
If you want a new TV, make sure you read our guide to buying a modern TV (and our guide to buying a gaming TV, too). We’ve also compiled a buying guide for the best TVs you can buy.
