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Camera Profile: Sony Alpha 7S III (ILCE-7SM3)

Technical reference for the implemented Sony Alpha 7S III sensor profile in suckless-ogl.

📊 Technical Specifications

Parameter Value Definition & Engine Role
Sensor Type 35mm Full-Frame CMOS Impacts focal length multipliers and Depth of Field (DOF) depth.
Sensor Size 35.6 x 23.8 mm Physical surface used for circle of confusion and bokeh scale.
DOF Simulation 35mm f/1.8 (Ciné) Shallow DOF with 2.0x anamorphic vertical oval bokeh.
Output Resolution 12.1 MP (4240 x 2832) Pixel pitch reference for grain/noise frequency.
Dynamic Range 15+ stops (S-Log3) High Dynamic Range (HDR) ceiling; maps to ACES highlight roll-off.
Dual Base ISO 640 / 12,800 Optimal signal-to-noise ratio points; triggers gain simulation shifts.
Color Space S-Gamut3.Cine Wide-gamut primaries; target for color grading transforms.
Gamma Curves S-Log3, S-Cinetone Logarithmic vs Cine-style transfer functions (EOTF).

🔍 Parameter Definitions

1. Sensor Size & Form Factor

In our engine, the Full-Frame format serves as the "1.0x" reference. It dictates the relationship between focal length (mm) and Field of View (FOV). A 35mm lens on this sensor provides a "standard" cinematic perspective without crop factor.

2. S-Log3 (Gamma Curve)

A quasi-logarithmic curve designed to preserve the maximum dynamic range of the sensor. It compresses the highlights and lifts shadows to fit more information into the 10-bit/12-bit container. In rendering, this is our "Linear to Log" intermediate step before grading.

3. Dual Base ISO (Dual Gain)

The Alpha 7S III uses two distinct analog circuits. Low Gain (ISO 640) for bright scenes and High Gain (ISO 12,800) for low light. In the shader, this should affect the Noise Floor and dark-region grain intensity.

4. S-Cinetone

A color science derived from the Sony VENICE cinema camera. It focuses on pleasing skin tones (natural mid-tones) and a "softer" highlight roll-off compared to standard Rec.709.

5. Anamorphic Bokeh (2.0x)

The profile now simulates high-end cinematic anamorphic optics by applying a 2.0x vertical stretch to the bokeh kernel. This results in the characteristic "oval" out-of-focus highlights and "waterfall" background stretching associated with professional cinema lenses.

📚 Sources & Technical Resources

⌨️ Runtime Controls

  • Apply Sony A7S III Profile: Press F8 during runtime.
  • Toggle 3D LUT Lattice Debugger: Press Shift + F10 while a LUT-enabled profile is active.