What Is An A/B Direct Switcher? - Blackmagicdesign ATEM Production Studio 4K Installation And Operation Manual

Another great advantage of the ATEM M/E style of operation is you can tie keyers to the
transition. This means when you do a mix transition, you can also fade on or off keyers at the
same time. This allows you to build up a composition, and then bring the whole lot on air at the
same time. This is what the next transition buttons do, and you can select background for
normal transitions, or select one or more keyers to transition them on air.
You can even press multiple buttons on the hardware control panel to tie multiple keys and the
background at the same time. There are also dedicated downstream key tie buttons to tie
downstream keyers to the transition. Downstream keys also have dedicated cut and mix
buttons and so are very flexible. Downstream keyers are always layered over the top of
everything including the transition, so are a great place to key bugs and logos!
Finally, when your live production is finishing, it's nice to have a dedicated fade to black (FTB)
control to fade everything to black! You can see the dedicated fade to black control on the right
side of the keyboard. This lets you fade everything to black, and helps make sure you don't
miss a layer. Fade to black is at the extreme end of the processing chain so you get a clean
fade of all sources.
The last part of an M/E style switcher is the select bus. This is above the program row, and
simply allows sources to be selected for effects processing and other purposes, and there is a
label above this to show what you're switching. The select bus is commonly used to select key
inputs, and aux outputs. It's a clean switch, so when used to select aux outputs, you get a
clean cut.
As you can see by this quick overview, M/E style of operation allows confident live production
with good feedback on what's going on and the state of your switcher and programming at any
point in your production. Once you learn the M/E style of operation, you can move between
models of production switchers with little retraining as they all work the same!

What is an A/B Direct Switcher?

If you have been using video switchers for a long time, then you might be used to older-style
A/B direct switchers and you can easily set your ATEM switcher to A/B direct switching in the
ATEM software preferences. See the Transition Control section of this instruction manual for
details about where to change this setting.
A/B direct switchers have an A bus and a B bus. One bus is the program bus which shows a red
button for the current program output. The other is the preview bus which has a green button
for the preview video. As you move the fader bar up and down, the buses switch so that the red
program button follows the fader handle. This is where A/B direct switching is really easy to use
as the buttons stay lit in the same positions and just switch color between green and red.
A/B direct switching becomes a little more confusing when the fader bar is not used to make
the switch. If you use a cut or auto transition button to bring your preview source on air, or if you
use more than one control panel connected to your switcher, the fader bar won't have moved
on the control panel that you are using. The red program output always follows the fader bar
handle and, as you haven't moved it, the red program light has to move to another button on
the same row and the green preview light has to move to another button in its row.
This can become quite confusing when sometimes using the fader bar to make switches, and
sometimes not, as the rows containing your preview and program buttons will sometimes switch
and sometimes stay where they are which has the potential to lead to mistakes.
This is why modern M/E style switching is preferable because you'll always find your green
preview button in the row labelled Preview, and the red program button in the row labelled
Program. It's always consistent and there are no surprises with M/E style switching.
Getting Started 9 9