Something you may encounter when buying a new TV is poor color uniformity on a black background, also known as “Dirty Screen Effect” or DSE for short. So what is causing it, and is there anything you can do about it?
What is the dirty screen effect?
The dirty screen effect refers to the uneven appearance of a solid color, specifically a gray, black, or white background, on a display panel. It can affect anything with a thin and modern display, from TVs and monitors to smartphones and laptops. The effect is named because, under the right conditions, it resembles a clouding of the display, as if the screen needed cleaning.
You can see the dirty screen effect by using full screen colors on your TV. Under normal viewing conditions, you may only notice the effect in very dark or very bright scenes. It can only be visible in a very dark room. Sometimes motion like panning (especially with solid colors like the green playing field in a sports game) can accentuate the effect.
@SamsungDE Can you please tell me how this vertical banding/dirty screen effect error falls within your product specification frame?! I’m pretty sure you wouldn’t use these images to promote your 2021 QLED range. Movement in the picture on my TV (e.g. camera pans) is even worse! pic.twitter.com/lmC9pQYFo2
— Matt Francombe (@FrancombeMatt) October 3, 2021
DSE mainly affects LED-backlit LCD panels, but effects similar to DSE can also be seen on OLED displays. For LCD screens, this is caused by manufacturing issues with the panel itself or uneven backlighting. In some cases you may be able to see the LED backlight grid behind a set that uses local full array dimming.
With an OLED, the effect means either a faulty panel or the banding that often occurs with near-black content. Photographing your display with a smartphone almost always enhances the effect compared to real-world viewing conditions.
You may have heard the term “panel lottery” used to describe buying a new TV. If your set shows signs of DSE, the “good” news is that very few panels look perfect when examined on full-field gray, white, black, or even color slides.
What can you do about it?
Before you set out to test your TV’s panel uniformity, consider this: If you can’t see any deviations in real-world viewing conditions, your panel is probably good enough. Many TV owners don’t notice a problem until they look for it. At this point, they notice imperfections or problem areas that are then difficult to ignore. The same applies to OLED devices with banding and dark spots.
If you absolutely must test your television in all its facets, do so when you first buy it so that you can make a warranty claim immediately. In the case of an OLED, you may be asked to “break in” it or run a pixel refresh cycle on it for a few hundred hours to mitigate banding issues before your request is granted.
There is nothing you can do to reduce the occurrence of DSE on an LCD as the problem is inherent in the manufacturing process. Websites like RTINGS test each set for the phenomena and post their results online, but differences can occur between different products of the same model made in the same year and factory. It’s a panel lottery!
New TV review: @SamsungUS Q900/Q900R 8k QLED. An excellent 8k TV with impressive picture quality. It has wide viewing angles, but contrast is similar to the Sony Z9F. Unfortunately, a lot of dirty screen effect is noticeable. https://t.co/tWXsRRrTLq pic.twitter.com/ENlJq31qQz
— RTINGS.com (@rtingsdotcom) March 27, 2019
If your TV shows some DSE under test conditions, or your OLED shows visible streaks, try to get it out of your head. If you’re not paying attention, it might be easily ignored and not even noticed while watching movies, streaming TV shows or playing games.
If it really bothers you and your TV is out of warranty – well, there’s always a new TV to buy. Of course, you’ll take another round in the panel lottery.
Buy a new TV?
If you’re looking to get a new TV, be sure to check out our guide to buying a modern TV (and our guide to buying a gaming TV too). We’ve also created a buying guide for the best TVs you can buy.