Lens flare is one of the most familiar light-related artefacts in photography, but it still catches people out during paranormal investigations. It appears when a strong light source hits the camera's lens at the right (or wrong) angle, causing bright shapes, streaks, or coloured blobs to appear in the final image. These effects can be dramatic, sometimes even taking on shapes that seem meaningful, but they always come down to how light interacts with the lenses and coatings inside the camera.

In simple terms, lens flare occurs because modern lenses are made of several pieces of curved glass. When bright light enters from a sharp angle, it can bounce around inside the lens barrel instead of travelling cleanly through the optics. Each internal reflection creates its own highlight or shape. On smartphones, where the optics are tiny and tightly packed, even a small light source can trigger a noticeable flare.

During paranormal...