What is 12G SDI
First of all SDI stands for Serial Digital Interface and is a family of digital video interfaces (SDI, HD-SDI, 3G SDI, 6G SDI, and 12G SDI), that was first standardized by SMPTE or The Society of Motion Picture and Television Engineers. The 12G-SDI standard was introduced simultaneously with the 6G SDI interface in 2015. It has support for Source image formats into a single or multiplex 12G-SDI 10-bit interfaces. Since higher bitrates are part of the standard, 12G-SDI supports 4K 60 from a single link and 8K 30 from a dual.
Image: SDI-standards
What are the advantages of 12G-SDI?
In short 12G-SDI supports higher resolutions, 12G reduces system complexity in a 4K workflow. Instead of 4 x 3G-SDI cables to get 4K, you need a single 12G-SDI cable.
How far does it go?
Several charts for the Recommended Transmission Distance exists.
Here below is an overview table of what we as Barco recommend to use:
| Cable type Belden | 3G-SDI | 12G-SDI |
| 1694A | 50 meters | |
| 4855R | 30 meters |
Note: Keep in mind that normal BNC connectors are not made for these high frequencies and will affect the useable length of the cable in great length. The isolation materials between the shield and the pin need to be optimized for high frequencies to give you the best results without too much interference or dropouts.
