Flare artifact showing spectral rings or arcs of rainbow color, caused by interference and diffraction at lens coatings — a signature of vintage glass with simple coatings.
The Rainbow Flare is the most colorful member of the flare family: concentric rings or arcs fanning out the spectrum from red to violet, usually around a hard light source within or just outside the frame. Physically, it's an interference and diffraction effect — light reflecting off the thin coating layers on lens surfaces overlaps in a wavelength-dependent manner, breaking down into its colors.
Why Vintage Glass Loves It
Modern multi-layer coatings are engineered to suppress precisely these reflections. Lenses from the 1960s to 1980s with single coatings or no coatings, on the other hand, allow enough residual reflection to pass through for interference patterns to appear in the image. This is why the Rainbow Flare appears in flare tests almost exclusively with vintage lens series and their modern recreations — you won't find it in clinically coated new glass.
On-Set Usage
It's provoked like any flare: a hard, point-like light source, a shallow angle of incidence, and a relatively open aperture. The color rings move with the position of the light source — small pans significantly alter the pattern, which can quickly appear restless with a moving camera. If you want the effect deliberately, work with a fixed source at the edge of the frame and test the angle on the monitor.
Practical Tips
- The effect depends on the coating, not the focal length — however, within a series, focal lengths flare with varying intensity. Test beforehand.
- One Matte Box wing too many and the flare is gone. If you want it, consciously leave the lens hood open.
- In post-production, a true Rainbow Flare is difficult to remove cleanly — the decision is made on set, not in grading.
Related terms
Quiz
1. Was beschreibt „Regenbogen-Flare" am besten?
2. Zu welchem Department gehört „Regenbogen-Flare"?