Judge Chris Tuohy said the new charges of offensive behaviour were normally considered low level and were generally used for public order issues, but "it has to be said that this particular offensive behaviour has to be at the very top of crimes of that nature, because exposing your penis deliberately in public to young females is highly offensive to say the least".
There were six victims - four of which were aged 12. The others were aged 14 and 15.
Judge Tuohy had victim impact statements from some of the girls, who said they now felt unsafe walking alone on the street.
One was also fearful because she knew the man had seen where she lived.
The judge said the man was "extremely fortunate" the charges had been downgraded.
He has one or two previous convictions from a long time ago, but they were not of this nature, the judge said.
The man's lawyer argued for him to be discharged without conviction, saying the effects of a conviction would be "long-lasting and profound".
"This was an aberration and the court can be assured by the fact he hasn't behaved like this before and he hasn't behaved like this since, that it won't happen again."
The man's partner was in court to support him.
The judge chose to convict the man and fine him $800 and $130 court costs.
But for reasons including the man's mental health, the possibility of job loss, and consideration of his innocent partner, Judge Tuohy granted a permanent name suppression application.