Baby Eternas: The Complete GFX100 II and X-H2S Cinema Ecosystem


With the GFX Eterna 55 officially moving from development into production, the “Cinema Ecosystem” we have been piecing together across the G-mount and X-series is finally complete. While we’ve previously covered the individual milestones—from the initial F-Log2 C release to the arrival of the Eterna 3D LUTs—the release of Firmware Ver. 2.50 acts as the final technical bridge.

The GFX100 II and X-H2S have officially earned their title as “Baby Eternas.” Here is the full breakdown of why these two cameras are the only ones capable of delivering the IMAX-certified color science of their $16,000 big brother.

The Hardware Foundation: 14-Bit vs. 12-Bit Readout

The reason the GFX100 II and X-H2S sit in a different class than the X-H2 or X-T5 comes down to the sensor architecture. Both cameras use Fujifilm’s Stacked BSI “HS” (High Speed) sensors—the same technology found in the Eterna 55.

This hardware allows for a 14-bit sensor readout in video. While the final files are recorded in 10-bit, the quality of the “source” data is significantly higher:

  • The HS Advantage: The 14-bit readout provides four times the raw color data per pixel compared to the 12-bit readout of the “HR” (High Resolution) sensors.
  • IMAX Mapping: The Eterna 3D LUTs were mathematically built for this 14-bit baseline. Because the GFX100 II shares the Eterna’s sensor DNA, the LUTs map correctly to the highlights and shadows, preserving the 14+ stops of dynamic range required for IMAX theatrical standards.

On the non-stacked X-H2, applying these LUTs to an F-Log2 C file often results in “thin” highlights or graying shadows because the LUT is essentially looking for 14-bit data that the 12-bit sensor never captured.

Codec Choice: ProRes HQ vs. H.265

To maintain the “elasticity” of an IMAX-certified image, your choice of codec is just as important as your sensor. While both cameras offer H.265 (HEVC), the “Baby Eterna” workflow thrives on ProRes 422 HQ.

  • ProRes 422 HQ: This is an intra-frame codec, meaning every single frame is fully encoded. When applying the heavy mathematical transforms of a 3D LUT, ProRes HQ holds its integrity. You won’t see the macro-blocking or “chroma smoothing” that can happen when pushing H.265 files in the grade.
  • H.265 (All-I/Long GOP): While more storage-efficient, H.265 is a delivery-first format. Under the stress of an Eterna grade—especially when pushing density or saturation in the shadows—H.265 can “break,” leading to pixelation in deep reds or fine textures like hair.

For any professional production where you intend to use the official Eterna LUTs, internal ProRes recording (ideally to an external SSD via the GFX100 II’s USB-C port) is the gold standard.

The Professional Unlock: Firmware 2.50

As we noted in our latest firmware coverage, the GFX100 II has moved beyond being a “stills camera that does video.” The addition of T-Stop displays, Wired Time Code Sync, and the Interactive Anamorphic Module (for correctly de-squeezing 1.33x, 1.5x, and 2x glass) provides the functional parity needed to sit alongside an Eterna 55 on a professional set.

Summary of the “Baby Eterna” Workflow

  1. Shoot F-Log2 C: This is the only profile calibrated for the 3D LUTs.
  2. Record ProRes 422 HQ: Ensures the image doesn’t break under the 3D transform.
  3. Monitor with T-Stops: Matches the industry standard for cinema lenses like the GF32-90mm T3.5 PZ.
  4. Apply Eterna 3D LUTs in Post: Standardizes your footage to the IMAX-certified baseline.

Previous FujiAddict Coverage:


Fujifilm GFX100II:
B&H Photo / Amazon / Adorama
Fujifilm X-H2S:
B&H Photo / Amazon / Moment / Adorama
FUJIFILM GFX ETERNA 55:
B&H Photo / Amazon / Adorama

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