Learning About BNC Video Cables & SDI Connectors

BNC cables are used for a variety of video applications and are technical in nature. When talking about a cable, you're referring to both the wire and the connectors as a unit. Depending on their construction, you can use BNC wires for different applications and various video standards.

What Is a BNC Video Cable?

BNC refers to the connector on the end of the cable and not the type of cable itself. BNC stands for Bayonet Neill-Concelman, named after the connector's developers. Originally produced to carry standard definition (SD) 480i analog video signals, these cables couldn't carry audio signals. Thus, they were bundled together with audio cables for this purpose. Similar to S-Video cables, you can use a BNC cable with SD sources such as older cable boxes, satellite receivers, and professional video legacy components. The modern standard for BNC video cables is SDI (serial digital interface).

Are SDI and BNC the Same?

Technically, the terms SDI and BNC don't refer to the same thing. SDI is a professional video standard developed for broadcast video operations. Where the original BNC cable comprised a 50-Ohm connector and RG-58 cable, an SDI cable uses 75-Ohm connector and RG-6 cable. Thicker cable and better connectors allow SDI to carry higher bandwidth signals. However, as SDI cables use BNC connectors, many still often refer to them as BNC cables in the industry. Since SDI is the only cable that still uses a BNC connector, SDI cables and BNC video cables of today are essentially the same.

Benefits of Using SDI

The SDI uses a cable with a larger copper center conductor, allowing you to send high-definition (HD), uncompressed video over longer distances. You can run SDI up to 300 feet before needing to re-lock the signal, making it the pro standard. You can also route SDI through a fiber optic cable for even greater distances. Coaxial cable used for SDI comprises of a PVC plastic jacket that's both flexible and durable, making this a perfect cable for professional fieldwork. HD SDI cables can support HD resolutions from 720p up to 4K at 60Hz.

Using professional video patch cables with BNC connectors allows professionals to use patch bays in a television studio for quick setups and equipment reconfigurations. Since SDI supports SD and HD video, you can use BNC camera cables for simple closed-circuit television setups or for professional 4K broadcast studio cameras. You can also make your own cable using bulk cable and video connectors, making it a good choice when you need custom configurations, lengths, or colors.

Although most consumer and prosumer devices don't support SDI, it's become the standard for the professional broadcast and audiovisual industries. There are adapters and converters to convert SDI to the more popular DVI and HDMI standards.

Whether you're looking for BNC video cables for professional use, BNC to RCA video cables for your home theater, or a wide selection of video cable accessories, B&H Photo and Video has the right cable for your needs.