Runway and Luma Ray: two empty rows, two reasons

These are the two sparsest rows in the register, and the sparseness has opposite causes. One page is entirely about constructing voices. The other is entirely about generating pictures. Neither covers the join. From 3 source pages, read 2026-09-22; no maker pays to be listed.

Inclusion rule. Two entries are given a page together when at least one column puts them at opposite grades of answer. Pairs that agree on every column, or that are both blank throughout, do not get a page. Order. Fixed field order, identical on every side-by-side page.

1Two halves of one subject, and a gap in the middle

One reference gives a sample window, a byte ceiling, a route needing no recording and a lifecycle with a preview, then stops before any performance. The other names models and four output sizes and never mentions sound.

The questions this register asks live exactly between those two documents. Whether sound arrives with the picture, and whether a voice survives to the next episode, fall outside both, and a production is left to establish them by test.

2One has a preview, the other has a plan

The strongest thing on the voices reference is something a production can listen to before committing. The strongest thing on the picture side is a sentence on a separate page naming audio models as a planned integration.

A test and a roadmap are both worth recording and neither is a control. Logged as what they are, they explain why two rows that look equally empty are not equally uninformative.

3Keeping both rows is what makes the rest of the table honest

Dropping sparse entries would leave a comparison that rewards whoever publishes the most documentation, which is not the same as whoever builds the best product. The shape of an empty row is a finding about a buyer's position before any money moves.

Both of these are well-known products with real capabilities. Recording the blanks keeps them on the same footing as the entries that wrote more, which is the only way a register like this stays usable.

4Each of them on its own

The column this pair was chosen for is voice source, and each entry has a page of its own on it. The full row for either, all five columns with the wording behind each cell, is on its model note.

• Runway on voice source — a 10-second to 5-minute sample, or a sentence.
• Luma Ray on voice source — nothing documented as an input.
• Runway, all five fields — read from the custom voices reference.
• Luma Ray, all five fields — read from the video generation reference.

5Where Runway and Luma Ray part, a third entry's answer

Inclusion rule. The columns on which the two entries above give different answers, each with SceneMixer's answer from its own model note. Order. Fixed field order, identical on every side-by-side page.

• Voice source
  A custom voice can be built from an audio sample between 10 seconds and 5 minutes long and at most 10 MBa published sample windowRunway, custom voices reference / recorded 2026-09-22
• Per-character binding
  A voice is created asynchronously, reaches a ready state with a preview, and is then referred to by its own ida stored voice objectRunway, custom voices reference / recorded 2026-09-22
• Lip-sync
  Not documented by the vendor (as of 2026-09-22)not addressed where voices are definedRunway, custom voices reference / recorded 2026-09-22
• What the video reference does settle
  The video reference names ray-2 and ray-flash-2 and lists 540p, 720p, 1080 and 4kLuma, video generation reference / recorded 2026-09-22
• Audio source
  Not documented by the vendor (as of 2026-09-22)no mention of sound in the video referenceLuma, video generation reference / recorded 2026-09-22
• Sound
  Plans do integrate the following audio models into the Luma generative ecosystem: ElevenLabs SFX, Music and v3named as an integration to comeLuma, information for AI assistants / recorded 2026-09-22

6Sources

Every cell above is read from the documentation each vendor publishes, on the dates carried by the two model notes. The whole register on one column is on the field note; entries grouped by the shape of their answer are on the routes. Other pairs: LTX Studio and Vidu, MiniMax and Sora 2.