Exposure

Available on Image changes and on scene jumps.

Drive the frame up in stops until it burns out to white, change images inside the white, then bring the next frame back down to a normal exposure.

The highlights burn out first, a saturated colour shifts as it goes, and the shadows are the last to give way. Through Color with a white color is the flat version, where every colour reaches white together.

Usage

import { Exposure } from "narraleaf-react";

image.char("image1.jpg", new Exposure({ duration: 1200 }));

// Burn harder, and stay on white before coming back down
image.char("image1.jpg", new Exposure({ duration: 2000, ev: 5.5, hold: 0.2 }));

// A night frame needs a stronger lift to carry its shadows up
image.char("image1.jpg", new Exposure({ duration: 1200, lift: 0.08 }));

Public Methods

constructor

• options: ExposureOptions
  • duration: number - The duration of the transition in milliseconds
  • ev?: number - The peak exposure in stops. The frame is driven to a gain of 2 ** ev, so each step of 1 doubles it. Defaults to 4.6.
  • lift?: number - The shadow lift (0–1) applied ahead of the gain. At 0 the shadows never reach white and a dark frame ends the burn as a silhouette. Defaults to 0.04.
  • hold?: number - The fraction (0–1) of the duration spent fully blown out. Defaults to 0.
  • easing?: TransformDefinitions.EasingDefinition - The easing function, see TransformDefinitions.EasingDefinition