you have any links to point to for this new owner to run some amateur tests and do a report out? lol
The easier to spot and less technical issues are the following:
Color Banding
For Color Banding, the user should attempt to play multiple videos of different quality/resolution etc via youtube and other higher quality sources.
If you spot something similar to the image below (on the left), it is color banding.
Disable any form of gradient control feature while looking for color banding and then play the exact same clips again with the gradient/banding reduction feature enabled to see how well it smoothens out banding. This is because with this feature active, while it artificially "smoothens" the color transitions, it can sometimes cause a reduction in detail and sharpness of the image. So it is best if the panel handles gradients smoothly without any form of gradient/banding reduction feature active.
Blooming
For Blooming/Local Dimming issues we can use the following videos below (this particular test only applies to TVs with Local Dimming Systems):
*Play these videos while the TV is in a Dark room/environment
Would be great to see if the TCL C825 is able to display circles in the dimming zones test video exhibiting minimal blooming. Test with Local Dimming set to High and then Medium. Check if while in this 2 settings are there any notable differences.
For this firework demo, check if the black background around each individual firework sparkle remains solid black. There should definitely be some blooming since the C825 is not using an OLED panel, but it would be interesting to see how well the local dimming zones on the C825 performs here.
Source:
https://www.rtings.com/tv/tests/picture-quality/local-dimming
LOCAL DIMMING VIDEO
As mentioned, our local dimming video represents how well the backlight can adjust when there's a moving bright image in a dark scene. We always show the maximum local dimming setting in the video, but we test for all the different local dimming settings and recommend which one performs best.
This test will show several things:
- Black Crush: When there's a bright object, sometimes the local dimming over-darkens the entire scene, resulting in highlights being 'crushed'. It's best if the TV avoids this.
- Blooming: Somewhat opposite of black brush, blooming causes bright objects to light up too many zones. This is noticeable when there's a glow around a bright object, like a street lamp or stars, and it could get distracting.
- Number and Size of Dimming Zones: With local dimming, different groupings of LEDs – called zones – are dimmed or brightened at the same time. With many small zones, it's easy to control how each zone affects the image. Fewer zones cover bigger areas of the screen, which could lead to more blooming. By looking at how much space is brightened around the white dot at any given time, you should be able to get an idea of the size of the zones. Also, we use this video to count the dimming zones. However, we don't publish how many zones there are because it's an estimate and not an exact number.
- Star Field: We use a Star Wars intro to evaluate how good the stars look. This is a way to see in real content whether there's blooming or black crush. On an ideal TV, each star is bright, and there's enough black space in between them.
- Subtitles: Sometimes, dimming zones are so big that they can't differentiate between subtitles and the content. If that's the case, subtitles can be over-brightened, or there's blooming around them, which could be distracting. You can see an example of bad subtitles here.
- Uniformity: Combined with our uniformity test, we see how uniform the screen is when there are bright highlights. We keep an eye out for any backlight bleed and blooming. Although our black uniformity test uses a test image, we use real content in this test and see if there are uniformity issues.
- Zone Transition Visibility and Speed: When a bright object moves between dimming zones, we want to see if there's any obvious blooming or if multiple zones light up. We also want to see how fast the zonal transitions are; does the new zone light up too fast, and how long does the old zone stay on the screen?
Here's an example of what blooming can look like if the TV has insufficient amount dimming zones or has a mediocre system that is unable to control those zones effectively.
The Sony X90J on the left has 24 dimming zones. The Sony X900E on the right has 48 dimming zones. They are both 55".
Source:
Due to insufficient zones, the X90J struggles to precisely brighten the Mortal Kombat logo without affecting the black background resulting in light haloing/blooming. The X900E which has more dimming zones performs better.
Panel Uniformity / Dirty Screen Effect
The next easy to spot test would be Panel Uniformity:
In this hockey video, if you spot any dark or distracting spots on your screen, this would be classified as "dirty screen effect" or screen uniformity issues. Set Local Dimming to high, medium and low and see if there are any notable changes.