Every night of the year — rain, hail or moonshine — Fran Davis steps out onto her back deck, aims her camera at the southern sky and fires the shutter. She then peers into the rear display, waiting a few expectant seconds for the long exposure to resolve.

For people like Fran, who trade sleep for the thrill of seeing the aurora australis, or southern lights, the camera is like a gold miner's pan. What might appear to the naked eye as nothing more than a smudge of haze across the stars can suddenly set the LCD screen alight like a breathtaking jewel.

Any sign of colour and Fran will dispatch a brief post online — something like, "Bright pink. Sth Bruny". The 66-year-old grandmother will then grab her camera gear and car keys, bid her husband goodnight and head out the door.

In half an hour Fran could be setting up her tripod on a wild bluff overlooking the Southern Ocean. She might spend an entire moonless night there, with only wallabies and possums for company, lost in the task of capturing another aurora.

Three years ago, the very thought of such a venture would have turned Fran's blood cold. She had been afraid of the dark for her entire life. This was not just a case of the jitters; Fran's phobia induced sheer, disabling terror.

She had never been able to reason away her little-girl conviction that horrific menace occupied every shadow. Even when living in the safest of suburbs, she couldn't bring herself to walk to her own clothesline at night. Finding herself alone in the pitch-black outdoors was her perfect nightmare.