For the church just getting into IMAG, or upgrading its old video system, the task of selecting the right video mixer can be daunting. There are dozens of switchers to choose from, with a dizzying array of feature sets, interfaces and price points. How do you choose the right one? As with many technology choices, the answer is, “It depends.”
Like cameras and projectors, audio mixers and speakers, a video switcher is a significant investment and needs to be considered carefully—not only on its own, but as part of a larger master technology plan. A well-chosen switcher will grow with you and provide reliable functionality for five to seven years, while a poor choice will frustrate you and your users until it is eventually replaced.
Though there are many choices out there, the good news is that most switchers offer the same basic functionality. Typically there are just a few features or functions that set one switcher apart from another, and it will be those small differences that determine the winner for your dollars. To get started with our decision-making process, let's consider the features that most switchers have in common.
TYPICAL FEATURE SETS
All video mixers will have at least one mix-effect bus (often abbreviated ME or MLE). Put simply, an ME allows you to transition from one source to another using a video effect such as a dissolve, wipe or 2- or 3-D move or effect. The ME also makes it possible to overlay one source (video or graphics) on top of another. Mixers suitable for all but the largest churches will have one or two MEs. More MEs offer more functionality and flexibility, but are also more complicated to operate. Some switchers are marketed as 1.5 ME, meaning you have one full ME plus a second that will do cuts and dissolves only.
Most switchers provide a method for keying video, or overlaying one source on another. This could be a picture in picture effect or—more commonly—putting graphics over video. Keyers can be upstream or downstream of the ME transition point; meaning they either persist during transitions from one camera to the next (downstream keying) or they do not (upstream keying).
Many switchers also offer auxiliary (aux) outputs. Similar to aux mixes on an audio console, an aux gives you the ability to route video to another source besides the main program out. This can be useful for feeding multiple screens with different sources. For example, you could send your program out to the IMAG screens, while routing your graphics through the switcher on an aux. If you want to take graphics to the IMAG screen (or IMAG to the graphics screen), you can. While most auxes are “cut only,” some switchers allow you to dissolve between sources.
Another feature that is appearing on more and more mixers is a built-in multi-viewer. A multi-viewer enables you to see many or all of your sources, plus preview and program on a single monitor. Some switchers even include built-in screens with a multi-view feature. Quite a few switchers are offering some type of media or clip store, which can make it very easy to create a walk-in graphics loop or overlay lower-third backgrounds or logo “bugs” on the video. Some even offer video-based transitions.
Not long ago, all sources connected to a switcher needed to be gen-locked (or sync'd) together or the picture would break apart and roll at every transition. Today, most switchers offer built-in frame synchronizers to line up video from just about any source. The better ones still allow you to gen-lock as many sources as possible, however, which keeps frame delays to a minimum. Up, down and cross conversion is also fairly prevalent these days. A typical church could have HD, SD and computer sources to mix together, and being able to do that inside the switcher makes cabling and system set up much easier. Finally, a tally function allows you to let the camera operators know when their camera is live.
APPLICATION: TWO- TO FIVE-CAMERA IMAG
A starting IMAG system would consist of between two to five cameras, a switcher and projection. When shopping for a switcher for a system like this, you would want to consider your input count, formats and resolution capabilities (SDI, analog, HD or SD) and the user interface. Most of the time simple cuts and dissolves are all you need, so a switcher full of amazing 3-D effects is just going to cost more than you need to spend.
While most switchers in this class offer a preset and program bus, a few A-B bus switchers persist. A preset/program workflow allows you to simply select the next shot on the preset bus, then “take” that shot to air using the T-bar or a take button. With this type of workflow, you don't have to keep track of which bus is live like you do with an A-B configuration, thus I almost always recommend preset/program switchers.
A work surface that allows your users (most likely volunteers) to get around quickly and easily without a lot of training will pay great dividends over the years. Choosing a switcher with a multi-viewer will minimize the physical footprint as well as the cost.
APPLICATION: MULTI-SCREEN VIDEO AND GRAPHICS
Moving up the complexity ladder, some churches will want to route all their video sources through the switcher. Many will have dedicated graphics screens for song lyrics and sermon notes plus other screens for IMAG. Often, these screens will cross over; for instance having IMAG plus song lyrics as lower-third graphics. In this scenario, a 1.5 or 2 ME switcher really shines; although it also comes with additional complexity.
Using a 2 ME switcher is like having two switchers in one; the first ME could be your IMAG mix while the second is your graphics screen mix. Depending on the complexity of the production, this could become difficult for one operator to manage, however, so keep that in mind. It is possible to do this on a single ME switch using auxes—what you choose will depend on how and how often you want to change the sources.
To get the cleanest possible overlay of graphics on video, you'll want to look for a downstream keyer that supports alpha keying. Your graphics source will have to support this, of course, and it will burn two inputs for each key source (the key, or cutout, and the fill), so keep that in mind when counting up the number of inputs you'll need.
APPLICATION: IMAG PLUS STREAMING
More and more switchers are including built-in streaming ports as well. For the church that wants to create an IMAG mix for the room and send that same mix out to the Internet live, looking at a switcher with a USB output of the program feed will make this job very easy. Of course, with convenience comes a cost; you're locked into whatever streaming format the switch manufacturer has chosen, and you may be limited on bit-rate and frame sizes. Still, it's a compelling option for many.
CAVEATS
As with most things in life, there are always trade offs and things to watch out for. First off, it's important to match the input and output capabilities of the switcher with the equipment you plan to use. For example, don't buy a switcher with only HD-SDI inputs if your cameras are all SD analog component (unless you plan to upgrade the cameras in the very near future). Yes, you can buy conversion boxes, but those add latency or delay, so we try to avoid that when possible. Conversion can work for those one or two oddball sources, but don't design a system that way.
You also want to match the resolutions of all the equipment. As mentioned earlier, most switchers will convert up and down, but those conversions add delay. As much as possible, pick one system-wide resolution and run everything the same. Minimizing conversations will keep the delay between reality and screen as low as possible.
Finally, as with any major equipment purchase, it's important to consider the user. While there are some mighty impressive switchers out there will lots of blinking lights and switches, they can be intimidating for the novice operator. Make sure to buy enough capability for today and the next five to seven years, but keep the user interface as simple as possible. Each switcher will have a slightly different workflow; try as many variations as you can to find the one that offers the greatest potential with the shortest learning curve.
Thankfully, there are very few truly awful switchers on the market today, so choosing will come down to finding the product that works the best for you and your church.
