Lens flare
Lens flare is an optical artifact that occurs when strong light – the sun, a lamp, a spotlight – scatters and reflects within the lens system of a camera or video camera. In UFO footage it often appears as a floating spot of light.
Lens flare is an optical phenomenon that occurs when the light of a strong light source does not only reach the sensor by the usual path, but is reflected or scattered multiple times on the surfaces of the lens elements and inside the camera. The result is a spot of light, a ring of light, a ray-like streak or a haze cast over the whole image.
How it forms
The surfaces of the elements of multi-element lenses, the aperture blades, protective filters and the internal parts of the camera can all cause internal reflections. The resulting spots typically lie along the straight line connecting the light source and the center of the image, often on the side opposite the light source. Their shape often follows the shape of the aperture, which is why they are circular or polygonal. The light source can also be outside the frame: a strong light just beside the edge of the frame can also cause flare.
Its role in UFO research
In the analysis of UFO and UAP footage, lens flare is one of the most common mundane explanations, especially for photos and videos taken at night or in a sunny sky. According to skeptics, some of the "unknown orbs" or "discs" seen in footage are such artifacts. A common example is the small, greenish or white "ghost spot" of phone cameras, which is a copy of a strong light source, such as a lamp or the Moon, mirrored across the center of the image. Among other things, analysts examine whether the spot, mirrored across the center of the image, follows the movement of a light source, whether there is a strong light source in the image or just beside it, and whether the same thing is visible from another camera or another angle.
An important distinction
Lens flare is not a property of the observed object in the sky, but of the recording device. If a spot, mirrored across the center of the image, moves together with a light source when the camera is turned, that strongly indicates flare. A stationary spot fixed to the image frame rather points to dirt on the lens or the sensor, or a pixel defect. Lens flare is often confused with bokeh, which is the blurred image of an out-of-focus light source. The evaluation is case-by-case in every instance: ruling out or confirming lens flare requires knowing the raw footage and the circumstances of the recording.