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Best File Format for ACES Rendering

Jean-Claude Conradie avatar
Written by Jean-Claude Conradie
Updated this week

When rendering in 3ds Max 2025 with Corona Renderer or V-RAY Renderer using the ACES (Academy Color Encoding System) color space, the best file format depends on your workflow needs. Here are the recommended options and why:


Best File Formats for ACES Workflow in Corona:

  1. EXR (OpenEXR, 32-bit Half or Float) – Best Choice

    • Why?

      • Supports high dynamic range (HDR) and linear color data, which is essential for ACES.

      • Retains all lighting and color information without clipping.

      • Supports multiple render passes (AOVs) in a single file.

      • Works well with post-processing in software like Nuke, DaVinci Resolve, or Photoshop (with plugins).

      • ACES is natively a linear workflow, and EXR preserves this correctly.

  2. TIFF (32-bit Float) – Good Alternative

    • Why?

      • Also supports HDR and linear data.

      • Works well for single-layer renders if EXR isn't needed.

      • Compatible with most image editors.

  3. PNG/JPG (8-bit) – Avoid for ACES

    • Why?

      • Lossy compression and limited dynamic range (8-bit) can degrade ACES color accuracy.

      • Only suitable for quick previews, not final renders.

Corona-Specific Settings for ACES:

  • In Corona Frame Buffer (VFB):

    • Enable ACES Output Transform (under Color Management settings).

    • Set Input Color Space to ACEScg (the default for CG workflows).

  • When saving EXRs:

    • Use "Half Float (16-bit)" for a good balance of quality and file size.

    • Enable "ZIP compression" (lossless) to reduce file size.

Post-Processing Considerations:

  • If compositing in After Effects, Nuke, or DaVinci Resolve, use EXR with ACEScg.

  • If working in Photoshop, use the ACES 1.2 LUT or an EXR plugin (like OpenEXR).

Final Recommendation:

Use EXR (32-bit Half Float) for best quality and flexibility in an ACES workflow.
Use TIFF (32-bit) if EXR isn’t supported in your pipeline.
Avoid 8-bit formats (JPG/PNG) for final renders in ACES.


This setup ensures you maintain accurate color, dynamic range, and flexibility in post-production. Let me know if you need help configuring Corona for ACES! 🚀

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