When churches are shopping for an audio mixer there's usually a spirited debate about feature set, sonic performance, ease-of-use, and rider-friendliness. This same debate should also apply to video switchers, but many times, churches and consultants are “audio-centric.” As a result, when ministries upgrade their video production switcher it often ends up being a “lowest price” event.
Gone are the days when churches that had video ministries used the only grade of equipment available: professional-grade. In the 1960s and 1970s, when many of these pioneering churches started their television ministries, they had what broadcast television studios used … Ampex two-inch quad Video Tape Recorders (VTRs), Norelco-Philips, IVC, RCA Plumbicon cameras, and Grass Valley composite video switchers. It was only in the 1970s that industrial or “semi-pro” equipment became available from manufacturers such as Sony, JVC, Echolab, and Panasonic.
Today, there is still a distinction between larger broadcast video switchers and lower-cost video switchers or more general-purpose multi-source scaler/switchers. But, as with all wise technical decisions, your ministry should do an accurate and honest needs-assessment to determine which is right for you.
Larger broadcast-based switchers have more inputs, and better quality keyers that cleanly insert text and graphics into live content, and auxiliary busses that can output alternative selectable feeds. They also include real-time effects (DVE) for motion animation of images, logos and text, as well as clip storage to record and play video sequences or frames such as church ministry logos, video shorts and announcements.
The one major feature that a broadcast-based switcher can provide is multiple mix-effects
(M/Es) busses. This allows for up to nine unique and different mixes for up to nine separate feeds. In other words, you could send one mix to the “live” IMAG for the people in attendance, a different mix for multi-site or satellite location playback with different graphics, and yet another mix for webcasting without graphics or additional announcement clips. Each feed could have its unique camera shot selection, or different graphics or backgrounds.
The analogy in audio would be group or aux outputs. Industrial or prosumer-level switchers have varying degrees of limitations: less inputs and outputs, lower-quality keyers, compatibility with fewer signal types, limited (or no) onboard graphics storage, etc.
Gone are the days when churches that had video ministries used the only grade of equipment available: professional.
HDMI can be a tricky interface. Many in our professional world call it “plug n’ pray.”
BASIC GUIDELINES
Whether this is your first or third switcher, some basic questions should be asked before purchase.
If you need to convert the computer graphics to HD-SDI, you have to make sure that the graphics card output either provides a 1080i or true 720p resolution at 60Hz. Otherwise, you have to purchase converters that also scale the output to “standard” HD resolutions, which in the USA are 1080i and 720p.
Some switcher manufacturers have optional card slots that allow for DVI or VGA connections and resolutions directly into the switcher.
HDMI is a popular format, but it can be a tricky interface. You have to watch the cable length and make sure that the connectors are solid and cables are professional-quality. Many in our professional world call it “plug n' pray.” We have seen situations where the HDMI source is not compatible with the switcher due to tighter specs from the switcher, or the use of different versions of HDMI between the source and switcher.
Also, many high-end broadcast switchers do not include frame synchronizers. All inputs, including computer signal converters, have to be frame-synchronized or GenLocked to a master clock or sync generator. This is very important in live IMAG situations, as using GenLock or frame synchronizer reduces the delay time between the camera signal and output going to projectors or LED walls. Without GenLock, the pastor or musicians will appear out of step and irritably delayed on the “big screen.” And worse, without sync, the result can be no picture or severely skewed image.
If you do not have any live camera sources, or sources that can tolerate a delay in the output image, then maybe a standard switcher/mixer/scaler is the more desirable and economical choice. These can be lower cost and easier to interface with existing equipment. Though some can be GenLocked for minimal delay. These units can often take a multitude of sources, but most commonly VGA, DVI, HDMI, analog composite and component video, and some include HD-SDI. Most output to VGA connections along with DVI or HDMI. These typically can also interface and convert to any number of resolutions usually oriented towards display or projection use.
Image quality can be noticeably different between switchers. In some units, we have seen definite “banding” between brightness levels instead of smooth transitions. Some don't appear as sharp in their output, and others appear noisier (static).
Some newer video mixers include multi-viewers that save money by showing the inputs and outputs on one large screen instead of separate monitors. These can be very helpful, and save money. We recommend using plasma displays at 1,920x1,080 resolution for use with multiviewers whenever possible. But we look forward to the day when OLED monitors becomes more affordable --- hopefully in about two years.
WRAP UP
We would be remiss if we didn't mention that there are some “all-in-one” switchers that are PC-based. They can offer a lot of bells and whistles and a lot of bang for the money. However, just as the audio industry has not really accepted any purely PC-based live mixer, I see the same issues here. At this time, I still have more confidence in dedicated hardware solutions rather than reaching into the PC's OS to process video …especially very high-speed video signals.
As you can see, the choices are many, and the facets of the decision complex. At the most basic level, a church that is considering buying a video switcher needs to examine: 1) what input formats are being switched, 2) how many different mixes (feeds) are needed in real time, and 3) the speed of after-sale service along with the price of parts and service. Remember that you will need this switcher on the weekend, and possibly during the week. Can you get the product serviced within a week if needed? Is there someone to answer questions when the input fails to show up or is out of sync?
Remember, the joke used to be that good video costs about 10 times more than good audio. It may not be that much now, but a good video production switcher can still be a large purchase—and the quality of your decision will be seen by all in the quality of your video presentations.
