HSV Grade

Grade colour selectively by hue, saturation, or value range. Wire Curve nodes into the adjustment parameters for per-hue control.

What it does

HSV Grade isolates a range of colour and adjusts it independently of the rest, the secondary correction of a traditional grading suite. Target picks how the range is selected: Hue takes a band of colours, Saturation takes pixels by how vivid they are, Value takes them by brightness. Everything inside the band is pushed by the Range Hue, Saturation and Lightness controls, with a Falloff that blends the edit in rather than cutting a hard line. Master Hue, Saturation and Lightness grade the whole image, and Mix blends between the original and graded result.

A Curve wired into any of the range adjustment inputs varies that adjustment continuously across the hue wheel instead of applying one flat value to the whole selection.

When to use it

ParameterTypeDefault
content_inOneOf([FieldOf(Color), FieldOf(Volume), CollectionOf(Crc), Collection, GpuGeometry, CollectionOf(Geometry), Color, ColorArray])
targetString"Hue"
master_hue_shiftNumber0
master_saturationNumber0
master_lightnessNumber0
mixNumber1
target_hueNumber0
hue_widthNumber30
hue_falloffNumber15
target_satNumber0.500
sat_widthNumber0.300
sat_falloffNumber0.150
target_valNumber0.500
val_widthNumber0.300
val_falloffNumber0.150
range_hue_shiftNumber0
range_saturationNumber0
range_lightnessNumber0
spatial_strengthField
strengthNumber1

Gotchas

Hue is measured in degrees around the colour wheel: 0 Red, 60 Yellow, 120 Green, 180 Cyan, 240 Blue, 300 Magenta. It wraps, so a selection centred near 0/360 still reaches smoothly across the red seam.

The Target Hue, Saturation and Value groups affect only the Target currently selected. Switching Target from Hue to Saturation does not discard the hue settings, it stops using them, so a grade that appears to have vanished may be sitting behind an unselected target group.

Falloff softens the edge of the selection, not the selection itself. Raise it when a graded region shows a visible boundary. Raise Width instead when the selection is not catching enough of the target colour.

Worked example

  1. Add an HSV Grade after an image and leave Target on Hue.

  2. Set Target Hue to the colour to isolate, 240 for blue, then raise Hue Width until the selection covers the range you need.

  3. Raise Hue Falloff a little so the edit blends instead of cutting a hard edge.

  4. Push Range Saturation up, or Range Hue Shift sideways, to grade only the selected colour, and use Mix to dial back overall strength.

See also

Colour Correct · Levels · Channel · Colour fields