One common misidentified UFO is the camera lens flare, also known as a veiling flare. Lens flares are optical phenomena that can destroy an otherwise perfect photograph and are usually unnoticed at the time a shot is made. They often appear as yellow or orange streaks, geometrically shaped spots, or a consistent haze in the picture that reduces overall contrast. Outdoor photographs will often produce this effect when the sun is behind the camera subject as opposed to when the sun is shining on the front of the subject.

Lens flares are caused by light reflecting inside the lens, lens surfaces, or internal components. All lenses will reflect a certain amount of light at the very edge of the lens where it meets the air. Modern lenses come with a coating to help reduce the amount of reflection, however, technology has yet to provide a lens that eliminates the pesky flare altogether. A lens hood, an external apparatus that attaches as an extension of the lens barrel to shade the lens, can eliminate many lens flares and is quite effective.

Complex camera lenses contain several air to glass interfaces. Each air to glass interface increases the potential for light to be reflected in photographs. Accordingly, a powerful zoom lens would be more likely to produce lens flares than a standard lens.

Lens specifications are rated in terms of "elements/groups". For example, a lens specification of 18/10 indicates that there are 18 separate lens elements within the lens barrel, however, 10 lens groups have been formed by cementing some of the individual lens elements together. The number of air to glass interfaces in a lens that are able to produce lens flares is usually double the number of groups, so the lens in our example would have 20 interfaces and therefore be prone to producing lens flares.