Skip to content
ArcBrush ArcBrush Docs

Exposure

Exposure
Color

Adjusts exposure in EV stops, working in linear light for natural-looking brightness changes.

Exposure adjusts image brightness in photographic stops (EV). +1 EV doubles the brightness, -1 EV halves it. Because it works in linear light space (degamma → adjust → regamma), the result looks much more natural than a simple brightness offset, especially when darkening.

Offset lifts or lowers the black point in linear space, which is useful for filling in crushed shadows. Gamma provides a final midtone correction after the exposure and offset are applied.

Parameters

Section titled “Parameters”

Adjust

Exposure EVNumber
Default: 0.0 Range: -5.0–5.0

EV stops; +1 doubles brightness, -1 halves it

OffsetNumber
Default: 0.0 Range: -1.0–1.0

Black level shift in linear space; positive lifts shadows

GammaNumber
Default: 1.0 Range: 0.1–5.0

Gamma correction; <1 brightens midtones, >1 darkens them

Mask

Mask FitChoice
Default: None

Mask sizing

  • NoneCenter the mask at its native size — no resizing. Unmasked regions are unaffected.
  • StretchStretch the mask to exactly match the image dimensions. May distort the mask shape.
  • FitScale the mask to fit inside the image, preserving aspect ratio. Letterboxes where needed.
  • FillScale the mask to fill the image, preserving aspect ratio. Crops edges if aspect ratios differ.
Notes

Works in linear light space (degamma → multiply by 2^EV → offset → regamma → gamma correct). Produces much more natural-looking brightness changes than a simple offset, especially when darkening. Alpha is preserved unchanged. Mask Fit only visible when mask is connected.

Pins: image (required), mask (optional). When mask is connected, the effect is blended with the original using the mask (white = full effect, black = original).

Usage Tips

Section titled “Usage Tips”
  • +1 EV doubles brightness, -1 EV halves it. Think of it like camera exposure compensation.
  • Use Offset to lift shadows without affecting highlights, which is great for recovering dark areas.
  • Gamma < 1 brightens midtones, Gamma > 1 darkens them. This is similar to Levels gamma but applied after exposure.
  • Connect a mask input to apply the exposure adjustment to only part of the image, enabling selective dodge and burn.
Section titled “Related Nodes”