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Values Lens

Open the Values lens to check lightness, contrast, and large value groupings in an image.

Values lens open showing a Notan overlay with the threshold bar and Levels stepper visible.

Strips color to reveal pure value structure. Two modes:

  • Perceptual Lightness: Tuned to human vision, better for painterly analysis.
  • Linear Value: Raw luminance values with no perceptual correction.

Reduces the image into equal tonal bands to reveal dominant value groupings.

  • Bands: Adjustable from 3 to 11 steps.
  • Histogram: Shows how much of the image lives in each tonal zone.

Collapses the image into discrete value groupings for large-shape clarity studies.

  • Levels: Choose 2 to 5 value levels with the stepper.
  • Thresholds: Each boundary between levels has its own draggable threshold handle on a multi-threshold bar. Drag any handle to shift where that boundary falls in the tonal range.
  • Simplify: A slider that also acts as an enable/disable control. Drag to zero to turn simplification off; drag above zero to enable it and set the blur radius, which softens fine detail before the grouping is applied.
  • Blend: Control how strongly the effect applies.