There are lots of types of cables with lots of different types of ends on them which can be complicated and stressful when your’re pushed for time getting a stream or other time sensitive event ready. Here is a list of all of the connectors you encounter whilst getting involved, although it may look like a lot, most of these you wont ever see and probably don’t need to know about.
The first thing to get your head around is that the signal being carried by a cable is not the same as the type of connector. For example the same cable with the same connector could carry an audio feed, a video feed, a lighting control feed or an internet connection; possibly all at the same time!
SDI over BNC – The BNC connector type is used for other things aside from video as it is secure and is perfect for maintaining signal integrity over long distances. BNC cables are a type of Coaxial cable. SDI is a form of video signal, the way it’s processed means it can travel very long distances (200m) without the quality of the signal being effected at all, it’s also capable of up to 4k 60p! SDI should always be your first choice for video as it is by far the most reliable, especially over long distances. When you can, convert other video types into SDI as close to the source as possible.
The next 4 are all consumer level video inputs, this means they are designed for shot range connections and often have other, sometimes unwanted ‘features’
DisplayPort – This has two different connectors, full size and mini, the full sized DisplayPort looks very similar to HDMI but is square on one side. The mini variant is a connector type that is also shared with Thunderbolt 1 & 2 (found below). DisplayPort is a very convenient format as it can ‘carry’ the other consumer level video and audio types. For example you can get a display port adaptor that has one DisplayPort input and two HDMI outputs, it can also carry embedded audio! It can handle up to 4k60p but is limited to a range of about 5m, which is far from ideal… DisplayPort and HDMI both have something called a handshake, this means when it is plugged in a check is made to verify that the devices at each end are valid devices and that they definitely work. Whilst this sound like a good thing, it’s actually massively inconvenient as it is very easy for there to be errors in this process that often cause the handshake to fail, this means that no video signal is sent! You also have to wait for the handshake to complete which can cost valuable second when setting up.
HDMI – There are 3 sizes of HDMI, full, mini and micro. HDMI can carry an embedded audio signal as well as video. Micro can be found on things like the Panasonic GH4 and mini can be found on the Canon XA25. HDMI can reach up to 20m, but it gets quite temperamental at that length, especially when used with an ATEM. HDMI has a few revisions, but the most commonly found versions will do 1080p60 and 4k30p. HDMI has something called a handshake same as DisplayPort, see DisplayPorts entry for more info.
VGA – VGA is an old analogue format, this means there’s not so much a max resolution it can carry, but the more you try and send down it the bigger the signal loss and the output. For example it was designed for 640×480 originally, whilst it can definitely do better than that, 1080p is about its limit.
DVI – There are lots of types of DVI, but I’m only going to mention two, DVI-D Dual Link and DVI-I. DVI-D is digital only and functions identically to HDMI, it is literally the same signal without audio, it still has the handshake though. When DVI and VGA were first around they were quite limited with resolution, eventually a method was developed that allowed people to use two cables to increase the max resolution. This was then replaced with Dual Link, this is essentially two cables in one sharing a single connector, it behaves exactly the same as one cable, but has the functionality of two, all it really means is higher resolution. DVI-I can transmit Digital or Analogue, allowing it to be adapted to a VGA output or a HDMI output.
Before we get into audio here’s a warning: Audio connections are way more complicated than video! There are only really 3 types of connectors to worry about, but each one has tons of sub types, each at a different level and possibly being power in at least 3 different ways. I am not going to explain it all here, if you want to find out more, find a Tonmeister or talk to Alan from film and tech production. You can read about the 3 different ‘levels’ here.
XLR(3 pin) – Used for analogue or digital inputs, can carry AES/EBU audio. Can be mono or stereo. Sometimes need two feeds for stereo sound, normally only one. XLR can carry power so can power mics and other equipment, known as Phantom power. You can read more about the many different types and uses of XLR in it’s own dedicated section bellow.
Jack (6.35mm or 1/4″) – The standard audio connector for instruments and amps. We have very little equipment that uses Jack connectors, the most notable being the Scarlet 2i2 USB audio interface. To input into the 2i2 you almost always need two for a full stereo mix.
Mini Jack (3.5mm) – The same kind of connector that you find on your phone or laptop, its essentially just a mini version of the Jack connector but you will only ever need one for stereo sound.
Mini Jack (2.5mm) – This connector probably should be in this section as its very rarely used for audio, it’s mostly used for remote controls, for example the zoom control on our Sony cameras.
AES/EBU over BNC – AES/EBU is a digital audio format, it can be carried by XLR or BNC cables and can have many feeds in a single signal.
Three-pin XLR connectors are by far the most common style, and are an industry standard for balanced audio signals. The great majority of professional microphones use the XLR connector. We use XLR for analogue and digital audio, COMS and most of our mics. The three-pin XLR connector is commonly used for DMX512, on lighting and related control equipment, particularly at the budget / DJ end of the market.
They are the standard connector for our COMS headsets. Two pins are used for the mono headphone signal and two pins for the unbalanced microphone signal. Another common use is for DC power connections for professional film and video cameras such as the two JVC 790 cameras. Some desk microphones with LEDs use them. The fourth pin is used to power the LED indicating that the microphone is on. Other uses for the four-pin XLR include some Scrollers (colour changing devices for stage lighting), AMX analogue lighting control (now obsolete) and some pyrotechnic equipment.
Five-pin XLR connectors are the standard for DMX512 digital lighting control. Additionally, Five-Pin XLR is commonly used for DC power in audio equipment.
Six-pin XLR connectors are used for stage lighting control applications. Another common use is professional stereo headset with balanced microphone (headphone left-pin 4, headphone right-pin 5, headphone common-pin 3, mic high-pin 1, mic low-pin 2, mic ground-pin 6).
Seven-pin XLR connectors are used to connect some valve (tube) condenser microphones to their power supplies (carrying signal, polarisation voltage, heater and HT). Used by several models of Le Maitre and Ultratec fog machines for remote control. An obsolete use for seven-pin XLR connectors was analogue lighting control signals, as well as for wired intercom in broadcast studios, specifically with Ward-Beck intercoms.
Ethernet – Mostly used simply as an internet cable, but cable of a lot more. There are a few revisions of Ethernet, we’re only going to look at CAT5, CAT5e and CAT6 & 7. You can convert pretty much anything into a signal that can be sent over Ethernet cables if you have the right adaptor. Ethernet cables practically always have an RJ45 connector (also called 8P8C). They are comprised of 4 twisted pairs of copper wires and are annoyingly awkward to make… Different types of Ethernet cable are limited to different speeds, for example CAT5 is limited at 100Mbs whilst CAT5e is limited at 1Gbps and CAT6 is limited at 10Gbps (at short distances ~33m). CAT6 also has a cross shaped plastic inside that helps it carry such high data rates but also makes it much more awkward to crimp the ends!
USB – Universal Serial BUS, used for most computer peripherals, if you don’t know what a USB is then you’ve done an amazing job of avoiding computers and I’m wondering how you’re reading this… There are many many types of USB, you can see them all below.
Thunderbolt – Thunderbolt is a type of computer connector, versions 1 & 2 use the same connector as mini display port, version 3 uses USB Type C which is reversible! Thunderbolt is a very very useful connector as it can carry almost any type of computer signal. A single thunderbolt 3 cable can carry and be split via adaptors into all of the following at the same time: Display-port (so by extension HDMI, DVI and VGA), Ethernet, USB, 3.5mm Jack, PCIe and it can even power whatever it’s plugged into (Up to around 40W)!