Cutsio Blog

Alexa 35 S16 Mode Post Workflow: ARRIRAW, ARRICORE, ProRes, and Vintage Lens Coverage

The complete post workflow for Alexa 35 and Alexa 35 Xtreme Super 16 mode — recording formats, resolution and crop handling, vintage lens metadata, and conform in a mixed Open Gate and S16 timeline.

How does Super 16 mode work on the Alexa 35 and Alexa 35 Xtreme in post?

Super 16 (S16) mode on the Alexa 35 and Alexa 35 Xtreme uses a sensor crop that records from the central Super 16 portion of the ALEV4 sensor, producing HD-resolution footage at higher frame rates than Open Gate recording. In post, S16 footage requires different resolution settings, a conform that accounts for the crop factor, and separate color treatment from Open Gate material shot on the same camera.

The Alexa 35 Xtreme introduced expanded S16 capabilities with frame rates up to 660 fps in Sensor Overdrive mode. The S16 crop is approximately 2.4x compared to the full Super 35 sensor — a 15 mm S16 lens provides the field of view equivalent to a 36 mm lens on the full sensor.

S16 mode is popular for:

• Maximum frame rates (330 fps standard, 660 fps with Sensor Overdrive)
• Vintage lens usage (S16 lenses from 16 mm film cameras)
• Anamorphic desqueeze monitoring with specific S16 anamorphic lenses
• Broadcast-style 4:3 or 16:9 HD delivery without downscaling

Working with raw camera footage? Check out How to Build a Searchable Library From ARRIRAW, RED R3D, and ProRes Footage.

Streamline your workflow with How to speed up video editing workflow 10x.

What recording formats are available in S16 mode?

The S16 mode supports ARRIRAW, ARRICORE, and ProRes recording, each with different resolution and frame rate characteristics.

| Format | Resolution (S16) | Max FPS (Standard) | Max FPS (Sensor Overdrive) |

| :--- | :--- | :--- | :--- |

| ARRIRAW S16 | 2048 x 1540 (2K) | 120 fps | Not available |

| ARRICORE S16 | 2048 x 1540 (2K) | 330 fps | 660 fps |

| ProRes 4444 S16 | 2048 x 1540 (2K) | 330 fps | 660 fps |

| ProRes 422 HQ S16 | 1920 x 1080 (HD) | 330 fps | 660 fps |

| ProRes 422 LT S16 | 1920 x 1080 (HD) | 330 fps | 660 fps |

ARRIRAW recording in S16 mode is limited to 120 fps because the uncompressed data rate exceeds the Compact Drive write speed at higher frame rates. For frame rates above 120 fps in S16, switch to ARRICORE or ProRes.

The S16 resolution is approximately 2K (2048 x 1540) or HD (1920 x 1080), depending on the recording format. This is substantially lower than the Open Gate 4.6K resolution, which affects downscale quality and reframing flexibility in post.

How do you handle the S16 crop in a mixed Open Gate and S16 timeline?

When S16 footage is mixed with Open Gate footage from the same Alexa 35 or Alexa 35 Xtreme, the timeline must accommodate two different resolutions and crop factors.

| Timeline Approach | S16 Playback | Open Gate Playback | Notes |

| :--- | :--- | :--- | :--- |

| HD timeline (1920x1080) | Native resolution | Downscaled from 4.6K | S16 is full resolution, Open Gate is downscaled |

| UHD timeline (3840x2160) | Upscaled 2x | Native (if 4K mode) or downscaled | S16 requires upscaling — quality depends on source |

| DCI 4K timeline (4096x2160) | Upscaled 2x | Downscaled from Open Gate 4.6K | S16 may show softness when upscaled to 4K |

For projects where S16 footage is used for high-speed slow-motion inserts, the recommended approach is an HD or UHD timeline where the S16 clips are displayed at their native resolution and the Open Gate clips are downscaled to match. This avoids upscaling artifacts on the S16 material.

If the final delivery is DCI 4K, S16 clips will require upscaling. Use Resolve's Super Scale or a similar upscaling tool to improve S16 image quality at 4K. The upscaling quality depends on the S16 recording format — ARRICORE and ProRes 4444 provide better upscale results than ProRes 422 LT.

How should vintage S16 lenses be handled in metadata?

Vintage S16 lenses — Zeiss Super 16, Cooke Kinetal, Angenieux 16 mm, and others — do not communicate electronic metadata to the Alexa 35 or Alexa 35 Xtreme. The lens data fields in the MXF or R3D header will be empty for vintage lenses.

For post, this means:

• No focal length metadata for vintage S16 lenses
• No aperture (T-stop) metadata
• No lens identification in the camera metadata
• The DIT or assistant editor must manually enter lens data into the clip metadata

The recommended workflow:

1. Document each lens used, including focal length and aperture, on the camera report
2. During offload, use the DIT software's metadata fields to enter the lens information
3. When uploading to Cutsio, include the metadata in the clip notes or custom fields
4. In DaVinci Resolve, manually enter lens metadata in the clip Metadata panel
5. For color grading, note that vintage lenses have different color rendering, flare, and contrast characteristics that may require scene-specific color matching

Cutsio's Visual Intelligence can tag S16 clips by visual characteristics, which helps identify vintage-lens footage even without electronic metadata.

How does the S16 color pipeline differ from Open Gate?

The S16 mode uses the same REVEAL color science and LogC4 encoding as Open Gate mode on the Alexa 35 and Alexa 35 Xtreme. The color pipeline is identical. The LogC4-to-Rec.709 transform, ALF4 look files, and ARRI Textures all apply the same way.

| Color Property | S16 Mode | Open Gate Mode |

| :--- | :--- | :--- |

| Color science | REVEAL (LogC4) | REVEAL (LogC4) |

| Log encoding | LogC4 | LogC4 |

| Color space | Alexa Wide Gamut | Alexa Wide Gamut |

| ALF4 support | Yes | Yes |

| ARRI Texture support | Yes | Yes |

| Codec data | ARRICORE uses 13-bit RGB logarithmic Sensor Log; ProRes depends on selected profile | ARRIRAW sensor data, ARRICORE Sensor Log, or ProRes depending on format |

The color matching between S16 and Open Gate clips from the same camera is straightforward because the color science is identical. The main visual differences come from the lens characteristics (vintage S16 glass vs modern S35 lenses) and the sensor crop (S16 uses the center portion of the sensor where optical performance is best).

How does Cutsio handle S16 footage in the dailies pipeline?

Cutsio's enterprise raw ingestion add-on handles S16 footage through the same pipeline as Open Gate footage. The review stream is generated at the native S16 resolution with the correct LogC4-to-video color transform.

For mixed S16 and Open Gate productions:

1. Upload all footage — S16 and Open Gate — through the same pipeline
2. Visual Intelligence indexes the generated review assets from both formats
3. Review streams display S16 clips at their native HD or 2K resolution
4. Share links include clips from both formats
5. Collections can be used to organize S16 and Open Gate material separately
6. The original camera files are retained for download and conform

The review experience for S16 footage is identical to Open Gate. The player displays the S16 clips at their native resolution, and the color transform is applied correctly.

FAQ

Can I shoot S16 mode on the standard Alexa 35 or only on the Xtreme?

Both the Alexa 35 and Alexa 35 Xtreme support S16 mode. The Xtreme offers higher frame rates in S16 mode (up to 660 fps with Sensor Overdrive) compared to the standard Alexa 35. The recording format options are the same for both cameras in S16 mode.

Does S16 mode affect the conform workflow?

Yes. The conform must account for the S16 crop factor. If the offline edit was done at HD resolution, the S16 clips should conform at native resolution and the Open Gate clips should be scaled to HD. If the conform is at 4K, the S16 clips need upscaling.

Are vintage S16 lenses worth using on the Alexa 35?

Vintage S16 lenses offer a distinct image character — softer resolution, unique flare patterns, and characteristic color rendering — that many cinematographers prefer for period pieces, music videos, and commercial work. The Alexa 35's clean sensor and high dynamic range pair well with vintage glass to create a modern-retro hybrid look.

Does Cutsio support S16 ARRICORE footage?

Yes. S16 ARRICORE footage can be handled through the enterprise raw ingestion add-on after format support has been verified for the production's camera settings.

What is the best recording format for S16 vintage lens work?

ARRICORE is a strong choice for S16 vintage lens work when the post pipeline supports it, because it keeps ARRI metadata flexibility at a lower data rate than ARRIRAW. ProRes 4444 is a good alternative when immediate compatibility matters more than decoder-level adjustment flexibility.