Runway Ruby: The Essentials

Last updated: September 15, 2026

Covers Runway Ruby

Runway Ruby converts any standard dynamic range (SDR) video into true HDR. Feed it a clip from Runway or any other model on Scenario and it upgrades the brightness range and color depth for HDR10, HLG, or 12-bit HDR ProRes displays, or exports a lossless HDR EXR frame sequence for a VFX pipeline. It is a delivery step, not a creative one: motion, framing, and content stay exactly as they were, only the dynamic range changes.

How Runway Ruby Works

Runway Ruby takes one SDR video as input and re-maps its tonal range to HDR, expanding highlight and shadow detail that was compressed in the original SDR grade. The source must not already carry HDR metadata: Runway rejects an HDR-tagged file on the way in. Clips up to 40 seconds long and up to 4096px on the longest side are supported.

Because the transformation is a dynamic range remap rather than a new render, a standard SDR screen (including this article's video preview) cannot show the extra range the file actually carries. Open the result on an HDR-capable display, or in an editor/player that reads HDR metadata, to see the difference. What the preview below can confirm is that motion and content are untouched.

Before (SDR source)

After (Runway Ruby, HDR ProRes 422 HQ)

A papercraft dog runs through an autumn park. Same 12s clip, same motion, before and after HDR ProRes conversion. · Open on Scenario

Before (SDR source)

After (Runway Ruby, HDR10)

An astronaut greets a spacecraft under an overcast sky. Same clip, before and after HDR10 conversion. · Open on Scenario

Output Formats

Runway Ruby delivers four output formats, chosen with the outputFormat parameter. Each targets a different downstream use:

HDR10

The most widely supported consumer and web HDR format. Delivered as an .mp4 with static HDR metadata, playable on HDR TVs, most modern browsers, and mobile devices.

A mountain biker rides through a misty forest at dusk, converted to HDR10. · Open on Scenario

An antique book floats in a shattered museum case, converted to HDR10. · Open on Scenario

HLG (Hybrid Log-Gamma)

Backward-compatible HDR: an SDR screen can still play an HLG file and show a reasonable image, while an HLG-aware display shows the full HDR range. Common choice for broadcast and streaming pipelines that need one file to serve both audiences.

A lone figure stands in a mossy glass atrium with a waterfall, converted to HLG. · Open on Scenario

A man watches a whale swim past a city skyline through an office window, converted to HLG. · Open on Scenario

HDR ProRes

A 12-bit .mov intended for editing and color grading, not final delivery. Choose a proresProfile to match your pipeline: 422 for a smaller, editing-friendly file, 422 HQ (the default) for a stronger balance of quality and size, or 4444 for maximum fidelity, including alpha, at the largest file size. See the dog clip in "How Runway Ruby Works" above for a ProRes 422 HQ example.

HDR EXR Sequence

A .zip of individual, lossless HDR frames in OpenEXR format, for VFX and compositing pipelines that need to grade or composite frame by frame rather than work with a compressed video container. No example is embedded here since the output is a frame archive rather than a playable clip; use the app deep links above to inspect a converted asset's metadata, or run a short test clip through outputFormat: "hdr_exr_sequence" to see the archive structure.

Parameters

Runway Ruby takes one video and two delivery settings. There is no prompt: the tool only remaps dynamic range, it does not change content.

video

Required. The SDR video to convert. Maximum 40 seconds and 4096px on the longest side. Runway rejects a source that already carries HDR metadata, so run Ruby on the original SDR export, not on a file already tagged HDR by another tool.

outputFormat

Sets the delivery format: hdr10 (default) for the most broadly compatible HDR .mp4, hlg for a backward-compatible broadcast-friendly .mp4, hdr_prores for a 12-bit .mov meant for grading, or hdr_exr_sequence for a lossless .zip of EXR frames. See "Output Formats" above for when to use each.

proresProfile

Only applies when outputFormat is hdr_prores. Choose 422 for the smallest ProRes file, 422 HQ (default) for the usual editing balance, or 4444 for maximum quality and alpha support.

Use Cases

  • Finishing AI-generated footage for HDR platforms: take any Scenario video output (Runway, Seedance, Wan, Veo, or others) and deliver it in the HDR format a streaming platform or client spec requires.

  • Broadcast and streaming delivery: convert a finished SDR edit to HLG so it plays correctly on both legacy SDR screens and modern HDR TVs from one file.

  • Color grading pipelines: pull an SDR generation into HDR ProRes so a colorist has real dynamic range headroom to work with in a grading suite.

  • VFX and compositing: export an HDR EXR sequence to composite AI-generated elements into a live-action HDR plate frame by frame.

  • Archival masters: keep an HDR ProRes 4444 master of a generated clip so future re-renders or re-edits start from the highest available quality.

Tips for Better Results

  1. Start from the highest-quality SDR source available. Ruby expands the range that is already there; it cannot recover detail that was clipped or crushed in a low-quality source.

  2. Never feed Ruby a file that is already HDR-tagged. Runway rejects it outright. If you are not sure, check the source's metadata or use the original SDR export.

  3. Pick the format for where the file is going, not for where it came from. HDR10 for the widest playback support, HLG for dual SDR/HDR delivery, ProRes for grading, EXR for VFX.

  4. Preview on an HDR-capable screen before judging the result. An SDR monitor, and this article's own video embeds, will not show the extra dynamic range even though the file carries it.

  5. Keep clips under 40 seconds and 4096px per side. Longer or larger sources are rejected; split a longer edit into segments first if needed.

  6. Default to 422 HQ for ProRes unless you have a specific reason not to. It is the balance Runway itself defaults to for most grading workflows.

  7. Use 4444 only when you need alpha or maximum fidelity. It produces significantly larger files than 422 or 422 HQ for a marginal quality gain in most cases.

Known Limitations

  • No content or motion change. Ruby only remaps dynamic range. It cannot fix motion artifacts, re-time a clip, or alter composition; use an editing model like Runway Aleph for that first.

  • HDR-tagged sources are rejected. The input must be genuine SDR. Re-export from SDR if a source was already processed by another HDR tool.

  • 40-second and 4096px caps. There is no way to process a longer or larger clip in one call; split it first.

  • The difference is invisible on an SDR preview. Article embeds, most laptop screens, and many phone screens will show the before and after clips as visually identical even though the "after" file carries real HDR metadata. Verify on an HDR display or by inspecting the file's metadata.

  • HDR EXR Sequence has no inline preview. The output is a .zip of frames, not a playable file, so it can only be inspected by downloading it or opening the asset in the Scenario app.