Gosugadget introduced this black level test which has been on the internet for a while and shared his test results.
 |
| Source: Lagom |
The grid of 5x4 squares of shades from 1 (black) to 20 (white) below is what you should be looking at if your display has a good black level. According to Gosugadget, most of displays are supposed to show the bottom 2 rows.
 |
| Source: Gosugadget |
Here are the test results on the gadgets he owns and I added a few.
[TV]
1. Panasonic VT30 (calibrated)= 1
2. LG LM9600 (calibrated) = 2
3. Samsung ES8000 = 6
4. Sony KDL 40BX450 = 7
[Smart Phone]
1. Apple iPhone = 2
2. Samsung Galaxy S2 = 16*(updated)
3. Samsung Galaxy S3 = 16*(updated)
[Tablet]
1. Apple iPad = 16*(updated)
[Laptop]
1. LG Xnote = 3
