Pro video blog…Produced by Philip Johnston DoP/Editor

8 or 10 bit it’s all hocus pocus to many of us so what do the figures mean in real life terms, I have trawled the internet to try and put this into plain man’s english.

In a nutshell…To start, 8-bit means that for red(R), green(G), and blue(B), the values 0 to 255 can be represented. For 10-bit, the RGB values can be from 0 to 1023. This means that per component, 10-bit is 4 times as detailed as 8-bit. Therefore, if you had a raw image with 10-bit depth, it would have a color palette 64 times as large (4x4x4=64) to represent the image on your screen. In the case of high definition video, with the exception of footage from EXTREMELY high end cameras (starting with the RedOne cinema camera and upward), you will never come across media of this scale. The reason is, it would require a signal of 3.125 gigabits per second to properly transmit this signal.

As you can see from the image above the 10 bit image is far more detailed the colours blend from one to another while the 8 bit image is blocky, you can see this effect on most 8 bit video cameras and is one of the less endearing features of the new large sensor camcorders.

While I had my Panasonic AF101 the main problem you were fighting was getting the balance between a less noisy picture and increasing the tendency for banding which is the drawback of any 8bit video setup.

So why was this not a problem in the days of DV…simple your picture information was a lot less, standard definition TV is 720 x 576. We are now we are seeing HD footage that is 1920 x 1080 which is like a magnifier to that same 255 bits of colour hence you get banding.

The new Panasonic AG-HPX250 camcorder is one of the new breed of camcorders with 10bit 4:2:2 giving you silky smooth pictures and no banding. 10bit is the future for all video camcorders, lets hope Sony and Panasonic update their present range of large sensor camcorders to take full advantage of that fantastic 10 bit processing.

As you can see having a 10 bit recording gives you 4x more colour information this is great for green/blue screen work and editing that needs colour grading. It’s all about striving for the best you can afford, the better your master footage is the more that can be done with it before degradation kicks in.

author

Having been working in the video business since 1988 I have amassed a great amount of knowledge of both the kit and production values over the last 30 years.

2 thoughts on “8bit v 10bit what does it all mean ?

  1. I assume the rainbow stripe image was an exaggerated dramatization. It looks like what 8-bit color used to mean: the 6 levels per channel “web safe” palette with 8 bits per pixel. Now it means 8 bits or 256 levels per channel.

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