Motueka motorcyclist Craig Alan Chambers died at the scene.
The court heard Lew fell asleep while driving south to Dunedin, after first driving from Tekapo to Oamaru.
He clipped the wing mirror of a car and a motorcyclist after drifting into the north-bound lane, before crashing into Mr Chambers.
Mr Chambers' wife Nicola Chambers told the court her life, and the life of her seven-year-old daughter had "changed completely''.
In a sometimes breaking voice she said her husband's death had had a "huge impact'' on their physical and mental health.
"He was always making things better - who is going to help me now?'' she asked.
Judge Kevin Phillips told Lew his concern was he must have been aware he was tired, but ignored that.
He gave Lew a 50% sentence discount for an early guilty plea, and community work he had already undertaken voluntarily.
