sparkle effect
SourceEffect01/ ORIGIN
A star filter is a piece of glass with fine lines etched into it in a grid. Any bright point in the scene diffracts along those lines and becomes a cross, and the number of points depends on how many directions were etched. Cinematographers and portrait photographers used them heavily through the 1970s and 1980s, and they date the footage instantly, which is why the look now reads as a period signal rather than as glamour.
02/ SWEEP
CELL sweep
03/ SPEC
This effect finds pixels above a brightness threshold and draws crossed streaks outward from them, imitating diffraction through an etched filter rather than a general glow. CELL runs from 1 to 8 pixels with a default of 2 and controls the spacing at which candidate highlights are sampled, so it determines how many glints appear. GLINT scales the length and brightness of each streak, and THRESHOLD is an advanced control over which highlights qualify. In kott it renders in natural colour so glints carry the hue of the highlight.
04/ FAQ
- What is a sparkle or star filter effect?
- It turns bright points into crossed streaks, imitating a star filter: a glass element with fine lines etched into it, along which bright light diffracts into a cross.
- How many points does a star filter make?
- It depends on how many directions are etched into the glass. Two crossing sets of lines give a four-point star, three give six, and so on.
- Why does a star filter date an image?
- They were used heavily in film and portrait work through the 1970s and 1980s, so the look carries that period strongly regardless of the subject.
