Regional Contrast enhances local contrast in midtones without affecting fine detail or creating edge halos. This effect is similar to the "Clarity" slider found in Adobe Lightroom and other photo editing applications.
The filter works by comparing each pixel to a blurred version of the surrounding region. Areas that are brighter than their surroundings get boosted, while areas darker than their surroundings get darkened further — creating a sense of depth and "punch" in the image.
Location: Blur and Sharpen
When to Use
- Add punch to flat footage — Makes images look more three-dimensional
- Enhance texture — Brings out surface detail in skin, fabric, landscapes
- Improve local contrast — Without affecting overall brightness/contrast
- Create dramatic looks — High values create a gritty, HDR-like appearance
Properties
Contrast Settings
| Property | Range | Default | Description |
|---|---|---|---|
| Amount | 0 - 100 | 50 | Strength of the clarity effect. Higher values increase local contrast more aggressively. |
| Radius | 5 - 50 | 20 | Size of the region used for contrast calculation. Larger values affect broader tonal areas; smaller values affect finer detail. |
| Mix | 0 - 100 | 100 | Blend between original (0) and full effect (100). Useful for dialing back an effect without changing other settings. |
| Mode | RGB / Luminance | RGB | Processing mode (see below). |
Output
| Property | Options | Description |
|---|---|---|
| Output | Final, Difference Only, Blurred, Original | Select what to display. Useful for understanding and fine-tuning the effect. |
Output Modes:
- Final — Normal processed result
- Difference Only — Shows the contrast detail being added. Gray = no change, bright = positive contrast, dark = negative contrast
- Blurred — Shows the blur used for contrast calculation
- Original — Bypass, shows unprocessed input
Quality (Advanced)
| Property | Options | Default | Description |
|---|---|---|---|
| Blur Quality | Fast, Normal, High | High | Number of blur passes. More passes create smoother, more Gaussian-like blur. |
Quality Options:
- Fast — Single pass box blur. Fastest but may show slight "boxy" artifacts.
- Normal — Two passes. Good balance of speed and quality.
- High — Three passes. Produces smooth Gaussian-like blur. Recommended for most uses.
Protection (Advanced)
| Property | Range | Default | Description |
|---|---|---|---|
| Shadow Protection | 0 - 100 | 50 | Reduces effect in dark areas. Prevents noise amplification in shadows. |
| Highlight Protection | 0 - 100 | 50 | Reduces effect in bright areas. Prevents clipping and blown highlights. |
Processing Modes
RGB Mode
Applies the contrast enhancement independently to each color channel. This can slightly shift colors in areas of high saturation but often produces more vibrant results.
Luminance Mode
Applies contrast only to the luminance (brightness) while preserving the original color saturation. This produces more natural results on skin tones and prevents color shifts, but may appear slightly less punchy than RGB mode.
When to use each:
- RGB — General footage, landscapes, when you want maximum impact
- Luminance — Skin tones, product shots, when color accuracy matters
Keyboard Shortcuts
| Key | Action |
|---|---|
| F1 | Output: Final |
| F2 | Output: Difference Only |
| F3 | Output: Blurred |
| F4 | Output: Original |
| F5 | Toggle RGB / Luminance mode |
Usage Examples
Subtle Enhancement
For natural-looking enhancement on interviews or talking heads:
- Amount: 30-40
- Radius: 15-25
- Mode: Luminance
- Shadow/Highlight Protection: 60-70
Punchy Look
For dramatic, high-impact footage:
- Amount: 70-100
- Radius: 20-30
- Mode: RGB
- Shadow/Highlight Protection: 30-40
Texture Enhancement
For bringing out surface detail (fabric, stone, skin texture):
- Amount: 40-60
- Radius: 10-15 (smaller for finer detail)
- Mode: RGB
HDR-Style Effect
For a gritty, hyper-detailed look:
- Amount: 100
- Radius: 30-40
- Mode: RGB
- Shadow Protection: 20
- Highlight Protection: 20
Tips
-
Start with the Difference Only view to understand what the filter is doing before committing to settings.
-
Use protection controls to prevent artifacts. High contrast can amplify noise in shadows and cause clipping in highlights.
-
Radius affects the "scale" of the effect. Small radius enhances fine texture; large radius enhances broader tonal regions.
-
Combine with other effects. Regional Contrast works well before color grading to add dimension, or after to punch up the final look.
-
Watch for halos. If you see bright/dark outlines around high-contrast edges, reduce Amount or increase the protection values.
-
Use Mix for fine control. If your Amount setting looks right but is slightly too strong, use Mix to dial it back rather than reducing Amount.
Technical Notes
- The filter uses a separable box blur (stacked multiple times for Gaussian-like quality)
- Processing is O(r) per pixel where r is the radius
- Shadow/highlight protection uses smooth falloff curves to avoid harsh transitions
- BT.709 coefficients are used for luminance calculation
- Alpha channel is preserved unchanged