OLED TVs have great picture quality, however, there are concerns about their long-term performance due to the possibility of permanent image retention, commonly referred to as burn-in.
Our previous 20 hours per day burn-in test is still running and the OLED TV already has permanent retention. That test is an extreme case, using patterns with a lot of static content.
Based on your feedback and comments, we have bought 6 LG OLED C7 which will play real, non-altered content. This should give you a better idea on what to expect depending on what you watch on your TV.
We will start this test within the next two weeks and, once all the content is finalized, update this article every two weeks. We will continue to do this for one year.
Week 14: (05/04/2018): Uniformity results have been updated.
Week 12: (04/19/2018): New uniformity photos have been taken.
04/10/2018: We contacted LG regarding the strange results in week 4. LG engineers visited our lab a few days ago and were able to confirm the 25% window on the Live CNN and FIFA 18 TVs are a result of a factory issue (see our video here). OLED TVs are produced in a hot process, and after cooling a 25% window is shown on each panel. Some TVs which haven't cooled completely can produce invalid results for the lookup table used by the 'Pixel Refresh' function, causing this 25% window to become visible. Only some 55" OLED TVs were affected during part of 2017.
As this is not an issue with the panel itself, it is possible to apply a fix to the lookup table. LG will apply this fix to anyone who presents this issue to their support, for free, even after the warranty period has long expired. They have fixed our two affected TVs (see the uniformity photos below). Note that this doesn't fix other uniformity issues as the result of static content, only the 25% window caused by a factory defect. LG has also confirmed that there is variation between panels, which is why some OLED appear more prone to developing uniformity issues (as in the case with our Live CNN (200 nits) vs Live CNN (Max).)
Week 10: (04/05/2018): Uniformity photos have been updated. LG engineers visited our lab, and we will post the results of their investigation and an update in the next few days.
Week 8 (03/23/2018): Uniformity, peak brightness and color gamut results updated. Increases in peak brightness across all TVs, but otherwise the measurements remain consistent.
03/13/2018: A reader has pointed out to us that it is actually a 25% window, not an 18% window which is becoming more apparent. A 25% window was displayed for a maximum of 20 minutes in peak brightness testing conducted in early January.
Week 6 (03/08/2018): Uniformity photos updated. Only minor changes since week 4.
03/08/2018: New: Video: OLED Burn-in Test Update Week 4
Week 4 (02/22/2018): New uniformity photos have been updated. Uniformity issues are clearly visible on the 200 nits CNN TV in red and magenta slides (but not in normal content). This is unusual, as we would expect the maximum brightness CNN TV to show uniformity issues before the 200 nits CNN TV. The
Week 2 (02/08/2018): Uniformity photos have been taken for all 6 TVs. No issues are visible.
Week 0 (01/24/2018): The source content has been finalized and the test has been started. Initial measurements and uniformity photos have been posted below.
The goal of the test is to provide an idea of the usage time of a 2017 OLED TV before burn-in becomes apparent, which will depend on your usage. To do so, we will replicate five different real-world conditions in an accelerated aging test. We will also independently test two different brightness ('OLED Light') settings with the same content to see the impact of this.
The TVs will all be controlled by a microcontroller to repeat a five hour on and one hour off cycle four times per day.
The 'Screen Shift' option will be enabled on all TVs, and 'Pixel Refresher' will be performed before each set of measurements taken on each TV.
They will all be playing real content (not test patterns), from live cable TV sources, video game clips or recorded sports. The brightness of all TVs (except the one identified below) will be set to 200 nits on a checkerboard pattern, with the content described below.
1. Live CNN
CNN is played live on the TV through a cable feed. CNN is a widely watched network news channel, and we have also received concerns regarding this channel specifically. This test is considered a control, with the 'OLED Light' set to a brightness of 200 nits.
2. Live CNN (maximum screen brightness)
As above, live CNN is played on the TV through a cable feed. However, for this TV, the 'OLED Light' is set to maximum, which corresponds to a brightness of 380 nits on our checkerboard pattern. This is to show the relationship between burn-in rate and 'OLED Light' with the exact same content and over the same time period.
Many pre-recorded football games are displayed on this TV to represent the usage of someone who is interested in a particular sport and will watch it regardless of the channel. It includes content from a variety of channels and with different teams, so overlays are located in different areas and team colors change. It includes many games to avoid too much repeating.
4. Live NBC
This test is informative for people who watch a lot of general TV, since NBC shows a variety of movies, TV shows, sports, and news. The source is a live cable feed and should be representative for a range of general TV content.
5. FIFA 18 gameplay
The goal of the content on this TV is to investigate the effect of a 'high risk' video game - one which has some bright, static areas which remain very consistent. We have received the most concerns about FIFA 18, and so many hours of gameplay footage are used to show typical usage, including many different teams and a mix of menus and gameplay without much repeating.
6. Call of Duty: WWII gameplay
The gameplay footage on this TV is to represent a relatively 'low risk' video game. It only has small areas which are static and an overall dim image without too many bright colors. We haven't received any reports of burn-in for this game yet, so consider it a baseline for a low risk game.
A NodeMCU microcontroller is used to control each TV at all times. It has 6 IR LEDs, which are connected to the IR receiver of each TV, to power them all on and off at specific intervals. The status and toggle times are logged via WiFi to a server, to verify accurate timing.
There are a few different 'pixel refresher' functions which run on LG OLED TVs. An 'automatic' pixel refresh runs when the TV is turned off after four hours of cumulative usage. This requires the power to be connected, and LG has told us that this takes between 7 and 10 minutes to complete. As a result, this pixel refresh is automatically run at each power cycle of our test (4 times per day).
There is also a 'manual' pixel refresher function which is toggled through the settings menu. This may take an hour to complete, and we manually run this before taking each set of photos (as described above).
Automatic Backlight Limiter (ABL)
The automatic backlight limiter reduces the brightness of the screen to prevent it from drawing too much power. This occurs when there are large bright areas and is why our 100% window measurement of OLED TVs is significantly lower than smaller window sizes (see here). This doesn't mean that increasing the 'OLED Light' will result in a dimmer image. The overall image is still brighter with a higher 'OLED Light' setting.
Results (Last updated 05/17/2018)
Peak brightness & Color Gamut
Every two weeks we will take photos of 50% gray, 100% red, 100% green, 100% blue, 100% cyan, 100% magenta, and 100% yellow patterns and post the photos here. Every two months we will measure the color gamut and HDR peak brightness of each TV.
- This test alone only demonstrates the effect of one of the use cases described above. It does not show the effect of changing between multiple sources (such as watching football 20% of the time, playing high-risk video games 50% of the time, and playing low risk video games 30% of the time).
The goal of this test is to provide an idea of an OLED TV's lifespan before burn-in becomes visible when watching real world content. This article will be updated every two weeks with the latest results from our real-world test, and how it should impact your buying decisions depending on your own specific usage.