Pulsating light in the sky

The photograph was taken by my father with his SLR camera in December of 1978 (Date unknown, time is approximate) around the Kaikoura area (Exact location unknown), on the South Island of New Zealand.
Sightings around this area in late 1978 are known in New Zealand as the 'Kaikoura UFO lights'.
My parents were the only witnesses present during the event in question (as far as they know).  The object in question is described by my parents as a pulsating light which appeared to be changing in shape and size.  Bright orange and white colours, changing in intensity.  No noise or smell.  It appeared for a number of seconds, travelling at a slow pace vertically but with no clear trajectory and then disappeared in the horizon.  No noise (when leaving) or trail left behind.  My parents are unsure regarding distance and size.
Witness elects to remain totally anonymous; provides no contact information.  PD