Frequently Asked Questions

Can I mix between multiple different formats?

The Blackmagic ATEMs do not have scalers on the inputs. This means that you must choose a single format for your mix. If you wish to include a source which is not at the same format as the ATEM is set to then you must use an external scaler to convert the source.

The BM ATEM 1M/E and 2M/E include a downconverter for the program output so it is possible to mix in HD and output your program to a standard definition output device. The ATEM TVS outputs only at its native resolution.

Can I connect a DSLR to the ATEM?

The ATEM switchers have HDMI inputs, so it is possible to directly attach a DSLR with HDMI output to the ATEM.

However there is slightly more to it that that! The following issues may impact upon your choice to use DSLRs..

Many DSLRs have onscreen menus or other graphics which are permanently displayed on their HDMI output, this is ugly at best and makes DSLRs running stock firmware unsuitable for live mixing. (some of the hacked firmwares are able to provide a clean output)

Run Time
Most of the current DSLRs do not work in video mode for extended periods of time, this is down to a number of factors including battery life and problems caused by overheating due to the chips not being designed for extended use in video mode.

Cable Length
HDMI cables are not suitable for long runs - anything above 10 meters is likely to cause issues resulting in dropped signals. The best solution to this issue is to convert the HDMI to HDSDI at the camera (you could use a blackmagic miniconverter for this task) HDSDI will travel a long way down good cable - well over 100 meters is possible with such an approach.

Format Considerations
Some DSLRs have very limited choices for output format, this can be an issue with the ATEM as you must choose a common format for all your sources. It is of course possible to use an external scaler to convert your DSLRs output to match the rest of your sources, though doing so can have implications both for latency and quality.

DSLRs are hard to use for live shows, stills lenses cannot smoothly zoom in-shot and the very short depth of field makes focusing tricky in live situations. Panning shots tend to bring out the moire and aliasing errors which ruin the image quality. These factors make DSLRs far more suited to locked off shots rather than expecting to use them in place of conventional video cameras with operators.

Can the ATEM mix audio?


The ATEM switchers strip embedded audio from their inputs. A single analog audio input is provided, this audio source is embedded into the program output stream.

What is the input to output delay on ATEM switchers.

Genlocked signal = 1 line
Frame synch = +1 frame
Multiviewer = +1 frame
Downconverter = +1 frame
DVE, content in the DVE will be +1 frame.

In situations where minimal delay is important then make sure you use genlocked cameras, run the ATEM in the same native resolution as the cameras (ie do not up/down convert in camera) and use a display device which has a matched native resolution to the cameras. Using external processing to convert or scale signals will add additional delay so try and avoid such processing.

What formats do the ATEMs output

The main outputs (program and aux outputs) will be 'native format' IE the same format as the internal processing is set to, and thus the same format as your inputs.

There is an additional down converted program output that provides SD video output, this is hardwired to the program output. (not available on the TVStudio ATEM)

What is Genlock? Why would I want it?


By using genlock (ref sync / blackburst) to synchronize your cameras the ATEM can bypass its frame synchronizer stage. This reduces the input -> output latency by 1 frame.

Is there additional equipment required to use the ATEM switchers?

Yes! In addition to the switcher unit (and optional control panel) you'll want to consider adding the following items (not all are required for all situations)

A Computer (mac or pc)
to run the ATEM control panel software, even with the hardware panel you need a computer for some configuration tasks.

A Network Switch
this will allow easy connection of control panels and computers to manage the ATEM features. I've found the TP-Link rackmount gigabit switches to offer good performance at a budget price point, in a format that is easy to mount in the ATEM rack. (for very simplest setups a crossover cable can be used to connect the control computer to the ATEM directly)

At least 1 1080i compatible monitor for the multiviewer output (either HDMI or HDSDI - DVI monitors will work with DVI to HDMI cables)

Mounting Hardware
A well ventilated, shock protected, rackmount flightcase, or racking system to hold the ATEM main unit. The ATEMs get very hot in operation and particular care should be given to the location of the unit in the rack and the ventilation systems to keep the rack cool. Some form of forced air cooling is appropriate, various rackmount fans can be found from broadcast suppliers and will be required to keep equipment temperatures reasonably cool.

A UPS protected power supply.
All broadcast equipment is sensitive to power fluctuations, as such it is important to provide protection against power spikes and outages. The best type of UPS is an "online UPS" which provides a fully isolated consistent power source for your equipment. The lower cost option is a "line interactive UPS". Personally I use the Eaton MGE Evolution UPS, a good quality affordable line interactive UPS system, available in a compact 1u form factor.

Input Scalers
Format converters to allow mixing of cameras or other sources which are in a different format to the format your running the ATEM in. (Blackmagic MiniConverters offer good value)

Output Scalers
Format converters to convert your output to another format (eg if you wish to mix in 1080i for a recording but output 720p for projection screens in the venue)

GPI / Tally
The Blackmagic ATEM GPI / Tally box (if you wish to provide tally outputs to your camera operators)

What are the internal media players used for?

The ATEM media players can hold short clips of motion video. The very limited length of these clips limits the usability of these clip players somewhat.
The media players are not designed as a replacement for tape or disk based playback of VT segments, rather they are intended to hold clips used in "Stinger Transitions" or as a motion "bug" used in a DSK for station branding purposes.
The playback of more traditional VT segments will (hopefully) be controllable from the ATEM control panels, the Echolab ATEMs shipped with VDCP control to allow instant clip recall from the panel and clip playback integration into switcher macros. We are hopeful that Blackmagic will implerment this functionality in the new ATEMs. (the inclusion of RS422 ports on the switchers indicates that this is likely)

How do I connect a computer playback system to the ATEM?

The best way to connect a computer graphics system to the ATEM is to use a computer with HDMI output connected directly to the HDMI input of the ATEM

If your computer has no HDMI then you may use a DVI to HDMI cable (Mac laptop user can use a minidisplayport to HDMI cable).
The only thing you need to be aware of is the computer output must be set to the same resolution and frame rate as the ATEM,
If you have trouble selecting the correct format from your computer then you might find an EDID manager such as the DVI Parrot from to be helpful.

Can the ATEM ethernet connection be used for streaming video?


The ethernet connection on the ATEMs is used for controlling the switcher functions (either from software or from the ATEM control panel)

Currently (July 2011) the only way to stream video from the ATEM is to output via conventional (HDSDI / Analog) outputs and capture these on a computer with suitable capture hardware and a streaming software such as Adobe FME. This MAY change when the USB3 output functionality is activated.