The aircraft had been cleared via a Standard Instrument Departure which required the aircraft to turn at three miles by Distance Measuring Equipment (DME) onto a heading of 170 degrees and to reach 2500 feet or above by 5 DME. The aircraft was to maintain heading 170 degrees until 7 DME, then turn onto a heading of 065 degrees to intercept the departure track. However, the aircraft was observed to turn at 3.5 miles onto a north-easterly heading and track to intercept the departure track. This was the first time the Captain had flown out of Adelaide, however, he was familiar with Standard Instrument Departures, having flown similar procedures overseas. On this occasion the Captain was concerned that he complied with the minimum altitude requirement and concentrated on this aspect to the detriment of the rest of the procedure.