The ATEM 1 M/E Constellation 4K is the entry model in Blackmagic's 4K Constellation range, adding UHD 4K capability and 12G-SDI ports to the familiar Constellation switcher construction. Ten individual 12G-SDI inputs support 12G/3G/HD-SDI signals and deliver to six 12G-SDI outputs, or to a webcam output via USB-C. A multiview output gives up to 16 routable windows, showing inputs, keyed video, graphics and stills from the media pool alongside the programme output, and each input connects to a built-in Fairlight audio mixer supporting up to 28 channels of audio. A reference video input is built in, and every input carries its own frame synchroniser, frame rate converter and format converter, so cameras, formats, non-genlocked sources and computer video can all be mixed and matched. Upstream and downstream keyers and effects run live and in real time with no rendering required, across 4 upstream and 1 downstream keyer with chroma and luma keying plus colour and pattern generators. Control runs from the integrated front panel, optional Blackmagic ATEM panels, or downloadable software for Mac and Windows.