Lower Thirds on an ATEM Switcher (Media Pool & Key/Fill)

Updated September 22, 2026

Blackmagic ATEM switchers key graphics in hardware, but they are particular about what they accept. There are two ways to get a lower third on air, and which one you use depends on whether you need animation:

• Static lower third — a PNG still in the ATEM media pool. Works on every ATEM, including the ATEM Mini family. The graphic can still fade in and out.
• Animated lower third — played by a computer and sent to the ATEM as key & fill. Needed on ATEM Mini models, whose media pool holds stills only (20 slots, no clips).

Method 1: PNG still in the media pool

Export: use premultiplied alpha

ATEM keyers expect premultipliedalpha — colour already multiplied by transparency. A standard PNG uses straight alpha, and on an ATEM its soft edges, drop shadows and gradients come out with visible halos. Turning off the switcher's pre-multiplied setting and adjusting clip and gain by hand only partly hides it.

In Titlo's export dialog, pick PNG (still frame) and tick Premultiplied alpha (ATEM). Export at your switcher's video format (1080p for most ATEM Minis), with the playhead on the frame where the lower third is fully on screen.

Load it and key it

1. In ATEM Software Control, open the Media page and drag the PNG into a free still slot of the media pool.
2. On the Switcher page, in the Media Player palette, select that still.
3. Open the Downstream Key palette: set Fill Source to the media player and Key Source to the media player's key, and keep Pre Multiplied Key ticked.
4. Use the downstream key's Auto button to take the lower third on and off air: it fades over the downstream key rate, which gives a clean mix in and out.

Method 2: animated lower third via key & fill

An ATEM Mini can't play an animation from its media pool, but it can key a moving graphic produced elsewhere. The graphic arrives as two video signals on two inputs:

• Fill — the lower third itself;
• Key — its alpha channel as a black-and-white matte (white = visible).

In the Downstream Key palette, set Fill Source to the fill input and Key Source to the key input. Match the pre-multiplied setting to what the player sends.

Players that can output key and fill:

• vMix with a supported Blackmagic card, playing the MOV ProRes 4444 from Titlo — see the vMix guide. vMix lets you choose straight or premultiplied output.
• ProPresenter, which can drive a fill output and a key (alpha matte) output on two screens, fed to the ATEM over HDMI.

This uses two of the switcher's inputs, so plan your camera count accordingly. OBS Studio cannot output a separate key signal natively, so it is not a fit for this method.

Larger ATEM models

ATEM switchers above the Mini range can store short clips in their media pool as image sequences. Titlo does not export image sequences yet, so for animation on those models use Method 2 as well.

Other setup guides

• Transparent Lower Thirds in OBS Studio
• Animated Lower Thirds in vMix with Alpha
• Lower Thirds with Alpha in DaVinci Resolve & Premiere Pro