1. The Architecture of RED IPP2: Image Processing Pipeline 2
In modern Hollywood cinema, RED's Image Processing Pipeline 2 (IPP2) is the computational backbone for cameras such as the V-Raptor, Komodo-X, and Monstro 8K. IPP2 was completely re-engineered to separate the raw sensor demosaicing stage from creative color grading and final output display transforms.
Under legacy REDColor workflows, color grading operations were locked to non-standardized curves that risked clipping saturated colors. IPP2 standardizes all sensor data into a wide-gamut, high-dynamic-range mathematical intermediate space: Log3G10 curve encoding within the REDWideGamutRGB primary space.
2. Log3G10 Curve: 33.3% IRE Middle Gray & 16+ Stops Latitude
The name Log3G10 describes the mathematical curve: it maps 10 stops above middle gray into 3 logarithmically spaced decades. Middle gray (18% reflectance) in Log3G10 is anchored precisely at 0.333 (33.3% IRE / 341 in 10-bit code).
| Luminance Zone | Stops Relative to Gray | Log3G10 IRE Value | 10-Bit Code Value | IPP2 Display Render |
|---|---|---|---|---|
| Deep Shadow Floor | -8.0 Stops | 4.5 IRE | 46 | Controlled Toe / 0-5 IRE |
| 18% Middle Gray Target | 0.0 (Baseline) | 33.3 IRE | 341 | 41.8 IRE (Rec.709 Standard) |
| Skin Tone Key Highlight | +1.5 Stops | 48.0 - 54.0 IRE | 490 - 550 | 60.0 - 68.0 IRE |
| 90% White Card Reference | +2.3 Stops | 58.0 IRE | 594 | 85.0 - 88.0 IRE |
| Specular Highlight Limit | +8.0 to +10.0 Stops | 100.0 IRE | 1023 | Asymptotic Roll-off |
In RED IPP2, pair "Medium Contrast" Output Tone Map with "Soft" or "Very Soft" Highlight Roll-Off. This prevents harsh digital clipping on specular practical lights while preserving natural saturation in high luminance.
3. Output Tone Map & Highlight Roll-Off Profiles
IPP2 decouples primary camera curves from the display rendering transform via two interchangeable parameters:
- Output Tone Map (OTM): Governs overall midtone contrast and shadow compression (Low, Medium, High). Most theatrical films standardize on Medium Contrast.
- Highlight Roll-Off (HRO): Controls how non-linear compression acts upon specular highlights prior to display clipping (Very Soft, Soft, Medium, Hard). Soft Roll-Off mimics photochemical film halation compression.
4. REDCODE RAW Debayering: Compression Ratios (HQ, MQ, LQ)
On newer RED DSMC3 cameras, REDCODE RAW utilizes simplified compression targets: HQ (High Quality ~2:1 to 3:1) for high-end cinema and visual effects, MQ (Medium Quality ~5:1 to 8:1) for narrative and commercial delivery, and LQ (Low Quality ~12:1) for documentary and broadcast scenarios.
5. Production DaVinci Resolve CST Workflow for RED IPP2
In DaVinci Resolve, grade REDCODE RAW non-destructively:
- Set Project Camera Raw Settings to Decode Quality: Full Res - Premium, Color Space: REDWideGamutRGB, Gamma: Log3G10.
- Maintain grading operations in the wide Log3G10 space between raw decode and output transform.
- At the final node, apply a Color Space Transform (CST) from REDWideGamutRGB / Log3G10 to Rec.709 / Gamma 2.4 using DaVinci Tone Mapping with Highlight Compression.