SNR Definition:
SNR_linear = Signal_mean / Noise_std
SNR_dB = 20 × log10(SNR_linear)
Where:
- Signal_mean: Average pixel value in test patch
- Noise_std: Standard deviation of pixel values (noise)
Sensor Noise Sources:
Total Noise = sqrt(σ_shot^2 + σ_read^2 + σ_fixed_pattern^2)
Where:
- σ_shot: Photon shot noise (Poisson distribution) = √N_photoelectrons
- σ_read: Read noise from A/D converter and electronics (constant)
- σ_fixed_pattern: Non-uniformity (calibrated out)
Shot Noise Dominance:
- At high signals: Shot noise dominates (√N behavior)
- At low signals: Read noise dominates (constant floor)
SNR_optimal ∝ √Exposure
Key Insight: Doubling exposure increases SNR by 3 dB (factor of √2)
Principle: Maximize exposure without clipping highlights to minimize overall noise
Mathematical Justification:
For sensor with read noise σ_read and shot noise √N:
Underexposure by N stops:
- Signal reduced by 2^N
- Shot noise reduced by √(2^N) = 2^(N/2)
- Read noise unchanged (dominates in shadows)
- SNR_penalty ≈ N × 6 dB (severe)
Overexposure by N stops (before clipping):
- Signal increased by 2^N
- Shot noise increased by 2^(N/2)
- Read noise unchanged (negligible in highlights)
- SNR_gain ≈ N × 3 dB (beneficial until clip)
Quantum Efficiency Consideration:
Photoelectrons = Photons × Quantum_Efficiency
Modern cinema sensors: QE ≈ 60-80%
Theoretical maximum SNR at full well:
- Full well: 60,000 e- (typical)
- Shot noise: √60000 ≈ 245 e-
- Max SNR: 20×log10(60000/245) ≈ 48 dB (per channel)
Practical SNR (including read noise):
- Read noise: 10-15 e- (modern sensors)
- Mid-gray (18%): 0.18 × 60000 = 10800 e-
- SNR_mid: 20×log10(10800/√10800) ≈ 40 dB
- SNR_shadow: 20×log10(120/√144) ≈ 36 dB (at 0.2% reflectance)
Native ISO: Analog gain setting providing optimal balance between highlight headroom and shadow noise
EI: Metadata adjustment affecting middle gray placement without changing analog gain
EI Adjustment Mathematics:
EI_change = 2× gain relative to base ISO
Example: EI 400 vs. EI 800 on sensor rated for EI 800
EI 400 (metering for +1 stop over):
- Camera expects more light
- Middle gray placed 1 stop higher
- More highlight headroom
- Cleaner shadows (better SNR)
- Risk: Clipping if not enough light
EI 800 (normal metering):
- Middle gray at optimal placement
- Balanced headroom and shadows
- Standard exposure
EI 1600 (metering for -1 stop under):
- Camera expects less light
- Middle gray placed 1 stop lower
- Less highlight headroom
- Noisier shadows (worse SNR)
- Benefit: Can use smaller aperture or lower light levels
Practical EI Strategy:
High-key scenes (bright overall):
- Use EI 400-600 for cleaner shadows
- Accept slightly larger apertures or more light
Normal scenes:
- Use native EI (typically 800 for ARRI, 640-800 for Sony)
Low-key scenes (dark overall):
- Use EI 1000-1600 to protect highlights
- Accept noisier shadows (less visible in dark scenes)
False Color Mapping Theory:
Each exposure zone mapped to unique color for visual evaluation:
Standard IRE False Color Zones (Rec.709 equivalent):
- 0-7 IRE: Purple → Noise floor, unusable
- 7-15 IRE: Blue → Deep shadows, Zone 1-2
- 15-30 IRE: Cyan → Shadow detail, Zone 2-3
- 30-55 IRE: Green → Lower midtones, Zone 3-4
- 55-70 IRE: Yellow → Middle grays, Zone 4-5
- 70-85 IRE: Orange → Skin tones, Zone 5-6
- 85-95 IRE: Red → Highlight detail, Zone 6-7
- 95-100 IRE: Magenta → Near clip, Zone 7-8
- 100 IRE: White → Clipped, no detail
Log-Specific Mappings (LogC4 example):
- 0-150 CV: Purple → Shadow noise floor
- 150-300 CV: Blue → Deep shadows
- 300-450 CV: Cyan → Shadow transition
- 450-600 CV: Green → 18% gray reference (400 CV)
- 600-750 CV: Yellow → Upper midtones
- 750-900 CV: Red → Skin tone highlights
- 900-1023 CV: Magenta → Warning zone
Zone System Integration:
Ansel Adams Zone System adapted for digital:
Zone 0: Pure black (0 IRE, 0 CV) - Noise floor
Zone 1: Deep shadow (7 IRE, 95 CV) - Texture barely visible
Zone 2: Shadow detail (15 IRE, 159 CV) - Darkest usable detail
Zone 3: Dark tone (30 IRE, 224 CV) - Textured shadows
Zone 4: Lower midtone (45 IRE, 288 CV) - Dark grays
Zone 5: Middle gray (55 IRE, 400 CV) - 18% reference
Zone 6: Upper midtone (70 IRE, 544 CV) - Light grays
Zone 7: Highlight (85 IRE, 672 CV) - Skin highlights
Zone 8: Bright highlight (95 IRE, 800 CV) - Detail visible
Zone 9: Near clip (100 IRE, 900 CV) - Specular highlights
Zone 10: Pure white (clip) - No detail
Digital Exposure Target:
- Zone 3-7: Critical tonal range
- Protect Zone 9-10: Avoid clipping
- ETTR places Zone 7-8 as high as possible
Incident Metering (Best Practice):
Procedure:
1. Set meter to match camera EI (e.g., EI 800)
2. Place meter in subject position, facing camera
3. Take incident reading
4. Set aperture to meter's recommendation
5. Verify: Middle gray should be at expected CV
Verification:
- LogC4: 18% gray should be ~400/1023 (10-bit)
- S-Log3: 18% gray should be ~410/1023 (10-bit)
- Log3G10: 18% gray should be ~450/1023 (10-bit)
Spot Metering for Scene Analysis:
Dynamic Range Assessment Workflow:
1. Spot meter darkest important shadow: T2.0
2. Spot meter brightest important highlight: T11
3. Calculate scene range: log2(11/2) = log2(5.5) = 2.46 stops
4. Verify camera DR: 14 stops available
5. Decision: Scene fits easily in camera DR
Alternative: High contrast scene
1. Darkest shadow: T1.4
2. Brightest highlight: T22
3. Scene range: log2(22/1.4) = log2(15.7) = 3.97 stops
4. Camera DR: 14 stops
5. Decision: May need fill light or accept clipped shadows
Log Waveform Interpretation:
LogC4 Waveform Targets (10-bit):
- Noise floor: 0-95 CV (purple zone on false color)
- Usable shadows: 95-300 CV (blue zone)
- Shadow detail: 300-450 CV (cyan zone)
- 18% gray: 400 CV (green zone)
- Skin tones: 450-650 CV (yellow-green zone)
- Highlights: 650-900 CV (yellow-red zone)
- Near clip: 900-1000 CV (red-magenta zone)
- Clip: 1023 CV (hard ceiling)
Waveform Monitoring Best Practices:
1. Set waveform to "Y only" or "Luma" for log
2. Disable RGB parade for log viewing
3. Check for clipping at top of waveform
4. Verify 18% gray at expected CV
5. Look for "flat-topping" indicating overexposure
6. Check for "noise floor" visible at bottom
IRE vs. Code Value Confusion:
Common Mistake: Reading log waveform in IRE
IRE (Rec.709 Gamma 2.4):
- 0 IRE = 0 CV (black)
- 90 IRE = 921 CV (white)
- 100 IRE = 940-1023 CV (super whites)
Log (LogC4):
- 0 CV = black (not 0 IRE)
- 400 CV = middle gray (not 45 IRE)
- 1023 CV = clip (not 100 IRE)
Solution: Set waveform to display CODE VALUES, not IRE
Most software: "Waveform: Data" or "Waveform: Linear" for log
On-Camera False Color Setup:
ARRI Alexa (LogC4):
1. Menu: Monitoring > False Color
2. Set pattern: "LogC" (not Rec.709)
3. Adjust thresholds:
- Green: 350-450 CV (18% gray ±1 stop)
- Yellow: 450-600 CV (skin tones)
- Red: 600-800 CV (highlights)
- Magenta: 900-1000 CV (warning zone)
Sony Venice (S-Log3):
1. Menu: Monitor > False Color
2. Set "S-Log3" mode
3. Adjust thresholds:
- Green: 360-460 CV
- Yellow: 460-640 CV
- Red: 640-820 CV
- Magenta: 920-1000 CV
False Color Exposure Strategy:
ETTR with False Color:
1. Increase exposure until skin tones show yellow-green
2. Check for magenta in highlights (warning)
3. If magenta appears:
- Reduce exposure 1/3 stop
- Or use negative fill/ND grad to reduce highlights
4. Verify green zone on middle gray (gray card)
5. Confirm no purple in shadows (noise floor)
Target Distribution:
- 10% purple (deep shadows acceptable)
- 20% blue-cyan (shadow detail)
- 40% green-yellow (midtones, skin)
- 25% yellow-red (highlights)
- 5% red-magenta (specular highlights)
- 0% pure white (clip)
Pre-Production Exposure Test Procedure:
1. Set up test scene with high dynamic range (10+ stops)
2. Light gray card to T4.0 at EI 800 (base exposure)
3. Capture sequence:
- EI 400: +2 stop over (T2.0)
- EI 800: Normal (T4.0)
- EI 1600: -1 stop under (T5.6)
- EI 3200: -2 stops under (T8.0)
4. Process all to linear or Rec.709
5. Evaluate:
Quality Metrics:
- Shadow SNR (measure noise in Zone 2-3)
- Highlight detail (check for clipping)
- Color accuracy (verify gray card neutral)
- Skin tone quality (subjective assessment)
Acceptable Exposure Range:
- Best quality: ±0.5 stop from optimal
- Acceptable: ±1 stop from optimal
- Usable: ±1.5 stops (with denoising)
- Unusable: >±2 stops (severe degradation)
Problem 1: Clipping Highlights
Cause: Over-aggressive ETTR pushes highlights past clip point
Symptoms:
- False color shows solid magenta/white
- Waveform shows "flat top" at 1023 CV
- Loss of specular highlight detail
- Irrecoverable information loss
Quantitative Detection:
Clipping Analysis:
- If >5% of frame at 1023 CV: Severe overexposure
- If 1-5% of frame at 1023 CV: Acceptable specular highlights
- If skin tones >900 CV: Risk of "plastic" skin
Recovery Limit:
- Within 0.3 stops of clip: Partial recovery possible
- At clip point: No recovery possible
- Above clip: Information permanently lost
Prevention:
1. Set zebras at 95% (warning before clip)
2. Monitor false color for magenta zones
3. Use waveform to check for flat-topping
4. Underexpose 1/3 stop if uncertain
5. Test with high-contrast scene before production
Problem 2: Excessive Noise in Shadows
Cause: ETTR not used, underexposing to protect highlights unnecessarily
Symptoms:
- False color shows purple in important shadow areas
- Visible noise in shadow regions after grading
- Banding in gradients
- Limited grading flexibility
Quantitative Thresholds:
Noise Acceptability:
- SNR >50 dB: Invisible noise (excellent)
- SNR 40-50 dB: Barely visible noise (good)
- SNR 30-40 dB: Visible noise, acceptable (fair)
- SNR <30 dB: Objectionable noise (poor)
- SNR <20 dB: Severe noise (unusable)
Measurement Method:
1. Extract 100×100 pixel patch from shadow area
2. Calculate mean and standard deviation
3. SNR = 20×log10(mean/std)
4. Compare to thresholds above
Recovery Strategies:
Underexposure Recovery:
- -1 stop: Lift in grade, 3 dB SNR penalty (usually OK)
- -1.5 stops: Lift + denoise, 4.5 dB penalty (may be OK)
- -2 stops: Aggressive denoise required, 6 dB penalty (risky)
- -2.5+ stops: Often unusable, consider reshoot
Denoising Tools:
- Temporal denoising (multiple frames)
- Spatial denoising (within frame)
- AI denoising (DaVinci Resolve, Neat Video)
- Trade-off: Detail loss vs. noise reduction
Misconception 1: "Higher ISO Always Means More Noise"
Reality: ISO is analog gain, but EI is metadata only
Example: ARRI Alexa at EI 400 vs EI 800
EI 400 (metering for +1 stop):
- More light hits sensor (1 stop advantage)
- Analog gain unchanged (sensor at base ISO)
- Result: 3 dB better SNR than EI 800
EI 800 (normal metering):
- Standard light levels
- Same analog gain as EI 400
- Result: Baseline SNR
EI 1600 (metering for -1 stop):
- Less light hits sensor (1 stop disadvantage)
- Analog gain unchanged (sensor at base ISO)
- Result: 3 dB worse SNR than EI 800
Conclusion: EI affects SNR via exposure, not gain
Misconception 2: "Log Encoding Adds Noise"
Reality: Log encoding redistributes existing noise, doesn't add significant noise
Log Encoding Noise Characteristics:
Linear (Rec.709):
- Noise appears uniform across tonal range
- Perceptual noise: Higher in shadows (eye sensitive)
- Perceptual noise: Lower in highlights (eye insensitive)
Log (LogC4, S-Log3):
- Noise amplitude: Similar to linear
- Noise distribution: More code values in shadows
- Perceptual noise: Lower in shadows (better quantization)
- Perceptual noise: Higher in highlights (fewer code values)
Net Result:
- Log does NOT significantly change total noise
- Log redistributes noise to less visible highlights
- Log improves perceived shadow quality
Misconception 3: "Always Protect Highlights at All Costs"
Reality: ETTR often allows some highlight rolloff for cleaner shadows
Trade-off Analysis:
Scenario 1: Protect highlights (0.5 stop under)
- Highlights: Perfect detail preserved
- Midtones: Slightly elevated (good SNR)
- Shadows: 0.5 stop noisier (3 dB penalty)
- Overall: Safe, conservative exposure
Scenario 2: ETTR optimal (0 stop, middle gray at spec)
- Highlights: Some rolloff (acceptable)
- Midtones: Optimal SNR (baseline)
- Shadows: Best possible SNR (no penalty)
- Overall: Best quality overall
Scenario 3: ETTR aggressive (+0.5 stop over)
- Highlights: Risk of clipping (some specular loss OK)
- Midtones: Elevated SNR (+1.5 dB better)
- Shadows: Cleanest SNR (+1.5 dB better)
- Overall: Maximum quality if highlights not critical
Decision Matrix:
- Commercial/narrative: ETTR optimal (Scene 2)
- Documentary/run-and-gun: Protect highlights (Scene 1)
- Controlled production: ETTR aggressive (Scene 3)
Error 1: Wrong Meter Calibration
Symptoms:
- Middle gray not at expected code value
- Consistent over/under exposure across all shots
- Difficulty matching exposure from day to day
Verification:
Meter Calibration Test:
1. Place gray card in even light
2. Take incident reading (meter at subject position)
3. Set aperture to meter recommendation
4. Measure gray card code value on waveform
5. Compare to specification:
LogC4: 400 ± 20 CV
S-Log3: 410 ± 20 CV
Log3G10: 450 ± 20 CV
6. If outside tolerance: Meter requires calibration
Error 2: Reflective vs. Incident Confusion
Problem: Using spot meter readings as if they were incident
Correct Usage:
Incident Meter (for setting exposure):
- Place at subject position
- Dome facing camera (toward light source)
- Measures light falling on subject
- Setting: Matches camera EI
- Result: Correct exposure regardless of subject reflectance
Spot Meter (for scene analysis):
- Point at specific area from camera position
- Measures light reflected from subject
- Setting: Matches camera EI
- Result: Reflectance values (Zone system)
Common Mistake:
- Taking spot reading of gray card
- Using as incident reading
- Error: Subject reflectance affects reading
- Result: Over/under exposure depending on subject
Error 3: Ignoring T-Stop vs. F-Stop
Difference:
F-Stop (Geometric):
f = focal_length / aperture_diameter
Pure geometric calculation, no transmission loss
T-Stop (Transmission):
T = f × √(transmission_factor)
Accounts for light loss in lens elements (typically 1/3 - 2/3 stop)
Example:
50mm lens at f/4.0:
- F-stop: f/4.0 (geometric)
- T-stop: T/4.5 (with ~11% light loss)
Implications:
- Light meter calibrated for T-stops
- Cinematography lenses marked in T-stops
- Photography lenses marked in F-stops
- Mixing them causes exposure errors
SNR (Signal-to-Noise Ratio): Ratio of signal power to noise power, expressed in decibels (dB). Higher values indicate cleaner images.
ETTR (Expose to the Right): Exposure strategy maximizing signal level without clipping highlights, minimizing overall noise by placing histogram as far right as possible.
False Color: Exposure visualization tool mapping code values to colors for rapid assessment of exposure zones across the image.
Waveform Monitor: Scope displaying luminance distribution across frame, essential for precise exposure evaluation and clipping detection.
EI (Exposure Index): Metadata parameter affecting middle gray placement without changing analog gain, different from native ISO speed.
Exposure Latitude: Range of acceptable exposures above and below optimal before quality becomes unacceptable, typically ±1-2 stops for log formats.
Middle Gray: 18% reflectance standard used as exposure reference, maps to specific code values in different log encodings (LogC4: ~400/1023).
Noise Floor: Minimum signal level where image information exists above noise, typically defined as SNR = 0 dB or SNR = 10 dB for usable signal.
Dynamic Range: Ratio between maximum non-clipping signal and noise floor, expressed in stops (log2) or decibels (20×log10).
IRE (Institute of Radio Engineers): Unit used for video signal level, 0-100 IRE mapping to black-white in Rec.709 gamma 2.4.
Code Value (CV): Digital number representing pixel brightness, 0 to (2^bit_depth - 1), used instead of IRE for log encoding.
Zebras: Camera overlay displaying striped pattern over areas exceeding user-defined threshold, typically set to 95-100% to warn of clipping.
Histogram: Graphical display showing distribution of pixel values across tonal range, useful for exposure assessment but less precise than waveform.
Incident Light: Light falling on subject, measured with incident meter by placing meter at subject position facing camera.
Reflected Light: Light bouncing off subject, measured with spot meter from camera position, affected by subject reflectance.
T-Stop: Aperture marking accounting for lens transmission losses, used in cinematography for accurate exposure.
F-Stop: Aperture marking based on geometric ratio, used in still photography, doesn't account for light loss.
Zone System: Exposure and development methodology dividing tonal range into 11 zones (0-10), adapted for digital from analog photography.
18% Gray Card: Standard neutral gray card reflecting 18% of incident light, used as exposure and white balance reference.
White Balance: Adjustment compensating for color temperature of light source, equalizing red, green, and blue channels for neutral reproduction.
Color Temperature: Warmth or coolness of light source measured in Kelvin, lower values warmer (3200K tungsten), higher values cooler (5600K daylight).
Tint: Green-magenta axis of white balance adjustment, compensating for non-blackbody light sources (fluorescent, LED).
Black Level: Pedestal offset added to signal preventing absolute zero values, subtracted during processing, affects shadow rendering.
White Clipping Level: Maximum code value before signal saturation, typically 4095 for 12-bit or 1023 for 10-bit.
Knee Point: Upper tonal value where highlight rolloff begins in some gamma curves, less common in pure logarithmic encodings.
Toe: Lower portion of gamma curve providing gradual transition from black, affecting shadow contrast and noise visibility.
Shoulder: Upper portion of some gamma curves providing gradual highlight rolloff, replaced by logarithmic encoding in log formats.
Gamma: Power-law relationship (Y = X^γ) defining tonal response, typically 2.2-2.6 for display-referred imagery.
Log Encoding: Logarithmic compression allocating more code values to shadows, fewer to highlights, maximizing perceived dynamic range.
Scene-Referred: Image data representing actual scene luminance values, independent of display characteristics.
Display-Referred: Image data optimized for specific display characteristics (gamma, gamut, brightness).
Middle Gray Placement: Decision of where 18% reflectance falls in code value range, affects overall brightness and noise characteristics.
ETTL (Expose to the Left): Opposite of ETTR, underexposing to protect highlights at expense of shadow noise, generally not recommended.
Rating: Using camera at different EI than native ISO to adjust middle gray placement and highlight/shadow balance.
Pulling: Reducing exposure during RAW processing (equivalent to having overexposed on set), improves shadow SNR.
Pushing: Increasing exposure during RAW processing (equivalent to having underexposed on set), increases shadow noise.
ISO Speed: International standard for sensor sensitivity, defined as exposure required to produce specified image quality.
Native ISO: Manufacturer's recommended analog gain setting providing optimal balance of noise, dynamic range, and highlight headroom.
Dual Native ISO: Feature on some cameras (Sony, Panasonic) with two analog gain circuits optimizing performance at different ISO ranges.
Base ISO: Lowest ISO setting providing maximum highlight headroom, often same as native ISO but sometimes lower.
Gain: Amplification of sensor signal, analog gain occurs before A/D conversion, digital gain occurs after.
Analog Gain: Amplification of sensor signal before analog-to-digital conversion, affects signal-to-noise ratio.
Digital Gain: Multiplication of digitized signal values, increases brightness but not SNR, essentially metadata adjustment.
Read Noise: Electronic noise added during sensor readout and A/D conversion, determines shadow noise floor.
Shot Noise: Fundamental noise from random nature of photon arrival, proportional to √N where N is number of photons.
Photon Noise: Alternative term for shot noise, fundamental physical limit, cannot be eliminated, only reduced by more exposure.
Fixed Pattern Noise: Non-uniformity in sensor response where individual pixels have different sensitivities, calibrated out via black subtraction.
Dark Current Noise: Thermally generated signal accumulated during exposure even with no light, increases with temperature and time.
Bandgap Noise: Fundamental electronic noise from semiconductor physics, sets ultimate limit on sensor performance.
Quantization Error: Error introduced when converting continuous analog signal to discrete digital levels, minimized by higher bit depths.
Dithering: Addition of controlled noise before quantization to randomize quantization error, preventing banding and posterization.
Banding: Visible steps in smooth gradients caused by insufficient bit depth or excessive noise reduction.
Posterization: Reduction of number of visible colors/tones in smooth gradients, similar to banding but in color dimension.
Macro-Blocking: Compression artifact where image divided into visible blocks (8×8 or 16×16 pixels) with discontinuous edges.
Compression Artifact: Visible degradation from lossy compression algorithms, includes blocking, ringing, mosquito noise.
Ringing: Oscillatory artifact around sharp edges caused by aggressive compression or sharpening.
Mosquito Noise: Buzzing artifact around high-contrast edges from inter-frame compression.
Just-Noticeable Difference (JND): Minimum perceptible change in brightness or color, approximately ΔL* = 1 in CIELAB space, basis for perceptual coding.
Weber-Fechner Law: Psychological principle stating perception of stimulus is logarithmic, basis for log encoding matching human vision.
Stevens' Power Law: Alternative to Weber-Fechner, perception proportional to stimulus raised to power, basis for gamma encoding.
Contrast Sensitivity Function: Human eye's sensitivity to spatial frequencies at different contrast levels, basis for perceptual optimization.
Visual Acuity: Ability to resolve fine detail, typically 1 arcminute or 20/20 vision, basis for resolution requirements.
Viewing Conditions: Environment brightness, screen size, viewing distance affecting perception of image quality and artifacts.
Target Display: Intended viewing environment and display type affecting exposure and grading decisions (theatrical, HDR, mobile, etc.).
Delivery Format: Final technical specifications for content (codec, bit depth, color space, dynamic range, resolution).
Color Grading: Creative adjustment of color, contrast, and appearance, performed after exposure and technical color management.
Color Correction: Technical adjustment compensating for scene issues or color reproduction errors, distinguished from creative grading.
Look: Creative color grading style or aesthetic applied to imagery, often achieved with LUTs or graded nodes.
Show LUT: Specific creative look developed for television series or film to maintain visual consistency across episodes and DP changes.
CDL (Color Decision List: Industry-standard format for elementary color corrections (SOP: Saturation, Offset, Power), primary color adjustment only.
ASC-CDL: American Society of Cinematographers standard for CDL format, ensuring interoperability between systems.
IDT (Input Device Transform): Color management transform converting camera-specific imagery to working color space (e.g., ACES).
ODT (Output Device Transform): Color management transform converting working color space to display-specific output (Rec.709, P3, HDR).
LMT (Look Modification Transform): Optional transform applied in ACES pipeline between IDT and ODT for creative look creation.
ACES (Academy Color Encoding System): Standardized color management architecture for device-independent color interchange throughout production pipeline.
OCIO (OpenColorIO): Open-source color management configuration system used in VFX and animation, alternative to vendor-specific LUT workflows.
CLUT (Color Lookup Table): 3D LUT mapping input RGB values to output RGB values for color transformation.
Shaper LUT: 1D LUT applied before 3D LUT to optimize distribution of values for better interpolation accuracy.
Tetrahedral Interpolation: 3D LUT interpolation method dividing color cube into tetrahedra for accurate value lookup.
Trilinear Interpolation: 3D LUT interpolation method using linear interpolation between cube vertices, faster but less accurate.
Prism Interpolation: Alternative 3D LUT interpolation method using triangular prisms, intermediate quality between trilinear and tetrahedral.
LUT Precision: Number of grid points in each dimension (17×17×17, 33×33×33, 65×65×65), higher values = more accuracy.
Cube File: Common 3D LUT file format (.cube) with human-readable text, widely supported.
3DL File: Alternative 3D LUT format used by some systems (Lustre, Baselight), binary format.
Look File: DaVinci Resolve-specific format for creative looks, can include multiple nodes, power windows, and keyframes.