These numbers are all about how much detail of colour the camera can capture. These are numbers that indicate how many colours the camera can distinguish.
Let`s go through what 10 Bit and 8 Bit etc means first.
8 bit means it can capture 256 shades of Red, 256 shades of blue and 256 bits of green. In total giving you over 16 million colour combination. Cameras such as Panasonic GH4 can do that.
Panasonic GH5 can record 10 bit. It can captures 1024 shades of blue, 1024 shades of red, 1024 shards of green. In total giving over 1 billion colour combination.
As you can see, the amount of colour detail that 8 bit and 10 bit can capture is wide apart.
BUT, the problem is that most monitors play back on 8 bits. Also Youtube can only playback 8 bit. Sometimes you see camera tests on Youtube, but an iPhone and RED camera would look the same due to this.
10 bit are usually good for colour correction. For example, you can distinguish the different colours in sky. You can colour correct in more detail than 8 bit. When you stretch the colours of 8 bit, it will give you an estimate of same colour, it will look pixelated.
Each addition of bits doubles the amount of colour information for each colour
1 bit : 2 tonal values
2 bit : 4 tonal values
3 bit : 8 tonal values
4 bit : 16 tonal values
5 bit : 32 tonal values
6 bit : 64 tonal values
7 bit : 128 tonal values
8 bit : 256 tonal values
9 bit : 512 tonal values
10 bit : 1024 tonal values
12 bit : 4095 tonal values
14 bit : 16383 tonal values
16 bit : 65532 tonal values
4:2:2 is Chroma sub-sampling. To capture the colours, you actually do not need to capture every colour of every pixel. 4:2:2 means for every 4 pixels wide and 2 pixel rows, 2 from the top row gets captured as colour and 0 from the bottom row has not colour data. But they are enough to make colour image. So, in the case of 4:4:4, it will capture all the colours.
You wouldn’t really notice the difference. But if you are colour correcting or dealing with the green screen footage, you would want to tweak those tiny pixels to have as much control to the image as possible.
I am a documentary/News cameraman based in London.