Switching the Switch

All of us in the studio industry have and use video production switchers of some type.  While some might be totally software-generated on a computer screen, most of the traditional switchers are exactly as they sound – large desks with plenty of buttons and switches!  I hate to sound so basic, but the large switchers that you see when the cameras pan around the control room of a studio (be it a live broadcast or post-production studio) are the reason I got into the industry!  Who wouldn’t want to push those buttons and make television programs?

While referred to as “vision mixers” in some circles (and in Europe), I prefer the original term: “video production switcher.”  They didn’t start out as elaborately as they’ve evolved into today.  As a matter of fact, they were very basic and stuck to their original purpose – switching between video sources, from one signal to another.  Take a look at an old switcher from the 1970’s:


The essential function of a video production switcher is to generate a master output for a real-time broadcast or video recording.  Usually, switchers are used at live events or for events where multiple sources need to be mixed in real-time.  However, they are also common in post-production studios for post-editing.  While conceptually comparable to audio mixers, video switchers take multiple input sources, apply desired effects and provide one or more “main” outputs.

Switchers can also be used to create various visual effects – from simple mixes and wipes between sources to advanced composite effects.  But with today’s technology, switchers are loaded with many more options than the basics listed here.  While they typically perform (in the very least) four types of transitions: fades, cuts, dissolves and wipes, the most sophisticated top-of-the-line switchers have built-in Digital Video Effects (DVE) machines.  DVE machines create custom transitions, (i.e., bouncing screens and varying title sequences). Not all effects are available on all switchers and, as you can well imagine, the cost of the switcher rises with the quality/quantity of effects available.

The real magic occurs in the bus.  The “bus,” you say?  Not the Greyhound type – but the computer network type.  That’s right – the bus network.

A video production switcher helps the operator perform their main task – keeping track of the video source(s) coming in and the main(s) going out.  Each video signal is fed into a switcher and assigned a button.  These buttons fall in rows across the switcher, with each row a “bus.”

Typically, there are three types of busses on a production switcher: the program bus, the preview bus and the mix/effects bus.  Most consumer and semi-pro switchers have one program bus, one preview bus and one mix/effects bus. High-end switcher models can boast three or four pairs of busses assigned to each of the different switcher functions, making the output combinations and possibilities virtually endless.

The preview bus and the program bus each have their own monitors; this is so the operators can see the program bus (which is the main output feed or the video that is being recorded or broadcast) with whatever shown referred to as being online.  The preview bus is used to select and preview the source, which is the video that is about to be put online.

So now that you’ve seen a picture of a switcher from the past, now look at a modern day switcher – the ATEM from Blackmagic Design (


With 4 upstream keyers, each with independent chroma, pattern, shaped and linear keying, you also get 2 downstream keyers and independent fade to black – Plus you also get extra innovative ATEM transitions, including: dip, DVE, graphic wipe and stinger!  ATEM’s built-in DVE allows you to fill your productions with 3D borders, light source and drop shadow!  You can even use the DVE for transitions!

In fact, Blackmagic Design has a full range of systems and options that can fit any studio need – broadcast or post!  From typical switchers with all the buttons and switches to software models with all the controls on a screen!


There are other companies that are in the professional video production switcher market – Sony‘s MVS-8000G, MVS-6000 & DVS-9000 Series of switchers are also high-end and produce outstanding capabilities as you would expect from Sony (


And don’t forget Grass Valley – their Kayak HD/SD and Kayenne XL Panels – upgradeable and packed with the features you most desire and need in a video production switcher of professional grade (

GV Kayak

Regardless of the company, once you have a professional video production switcher under your fingers you can pump-up the output and really edit any lackluster video groups into a truly polished, exceptional and expert production.  It’s all about having the right tools (ain’t that the truth?)  So, for more of the right tools, keep reading and stay blogged-in!

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Editor-In-Chief, Publisher at Broadcast Beat Magazine, LLC.
Ryan started working in the broadcast and post production industry at the young age of twelve! He has produced television programs, built large post production facilities, written for some of the industry's leading publications and was an audio engineer for about ten years. Ryan previously wrote for Broadcast Engineering Magazine, Creative COW and his projects have been featured in dozens of publications.
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