Lens flare occurs when strong light enters the lens and scatters off internal glass surfaces, creating visible artifacts in the image. It can appear as bright streaks, polygonal shapes, a hazy wash of light, or colorful circles stretching across the frame. While traditionally considered a flaw, lens flare is now also used as a deliberate creative effect.
What Causes Lens Flare
When a bright light source (the sun, a streetlight, a spotlight) hits the front element of your lens, some of that light bounces between the internal glass elements instead of passing straight through to the sensor. Each reflection creates a secondary image of the light source. The shape of these secondary images often matches the shape of the lens aperture blades, which is why you see hexagonal or octagonal shapes in flare patterns.
Types of Lens Flare
- Veiling flare: A hazy, washed-out look across part or all of the image. This reduces contrast and makes colors appear faded. It happens when stray light floods the lens without creating distinct shapes.
- Ghosting: Distinct bright shapes (circles, polygons, streaks) that appear in the image, often in a line extending from the light source. Each ghost is a reflection between two lens surfaces.
How to Prevent Lens Flare
- Use a lens hood: The most effective prevention. A properly designed lens hood blocks light from entering at extreme angles. Always use the hood that came with your lens.
- Shield the lens: Use your hand, a hat, or a piece of cardboard to block the light source just outside the frame edge.
- Choose coated lenses: Multi-coated lens elements reduce internal reflections significantly. Higher-quality lenses generally have better anti-flare coatings.
- Keep lenses clean: Fingerprints, dust, and smudges on the front element scatter light and worsen flare.
- Adjust your angle: Small changes in camera position can move the light source out of the flare-producing zone.
Using Lens Flare Creatively
Lens flare can add warmth, atmosphere, and a sense of sunlight to an image. Golden hour shooters and portrait photographers often position the sun just at the edge of the frame to create intentional flare. The key is control. Remove the lens hood, angle toward the light source, and experiment with different positions until the flare adds to the mood rather than obscuring the subject. Stopping down to a small aperture (f/16 or f/22) turns point light sources into starburst shapes, which is a related but distinct effect.