Was it an illusion, lens trickery, or something a little more mysterious and extra-terrestrial?

Te Puke schoolgirl Tiarah Kokiri was at home, on the deck, messing about with her mobile phone.

'I took a photo of the sun. Not for any particular reason,” says Tiarah. Then later, when sifting through her photos she spotted it. A bright ball of light with a pink and red halo.

What was it? A lunar interloper? A second sun? No-one was mentioning Unidentified Flying Object but they were certainly thinking it.

'Best to leave it as a UFO,” says photographer Bob Tulloch, when The Weekend Sun went to him for an explanation. 'It makes a better story.” Despite his delightfully cynical attitude to the media, the very experienced lens man couldn't help. 'Sorry, I really don't know.”

So we went to Carters Photographics in Grey St. They could only guess.

'Might be the ceiling light reflecting on the glass window that she was shooting through.” An interesting and plausible theory. But no! Because Tiarah was sitting outside on the deck when she took the photograph.

The Weekend Sun went to another eminent Tauranga shooter, Quinn O'Connell. 'Looks highly like lens flare to me,” says Quinn. 'Often happens when shooting into the sun.” Refracted light, light bending, lenses doing wonderfully unfathomable things with light beams.

Next we went to Simon Maxwell of Islands Films. 'Without knowing what lens was used I would say it's probably some sort of optical refraction in the lens,” says Simon.

'She's obviously shooting into the sun and some lenses do produce odd artifacts as light bounces around between the various glass elements.” Artifact, in this sense, meaning an undesired or unintended alteration in data introduced in a digital process.

And then to our own inimitable cameraman, Bruce Barnard. It was him who broke it to Tiarah that unfortunately she hadn't captured definitive evidence of inter-galactic travel.

'Refracted light,” says Bruce unequivocally.

'The lens of a camera is constructed with several bits of glass or plastic and that is used to focus the light onto the sensor that captures the image.” Ok so far.

'As some of the light moves from one part of the lens to another some of the light reflects off the surface of the lens and, in this case, produces a ghost image,” explains Bruce. 'The effect is more often created when the bright light causing the ghost image, in this case the sun, is not centered in the picture.”

Refraction is the bending of light as it passes from one transparent substance into another. The bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Even our eyes depend upon bending of light, because without it we wouldn't be able to focus light onto our retina.

So the word of the day is 'refraction” and a science lesson prompted by a simple spontaneous photo shoot on Tiarah Kokiri's deck ends with still no conclusive evidence, one way or another, on the existence of UFOs.