James William Davison's belief that his possession of the material was harmless "could not be more wrong", according to Justice Michael Elkaim.

During Davison's sentencing on Wednesday, the ACT Supreme Court heard police had raided the 49-year-old's home and found 827 files of child abuse material on his computer.

The files were mainly offensive photos of children, but among them were graphic videos of sexual acts and even some objectionable cartoons.

"I was asked to view some of the images, which I did," Justice Elkaim said.

"Suffice to say their possession displays a depravity which is alien to normal human behaviour".

The judge said the number of files was "significant", and it was unclear how long Davison had had them.

He was concerned that while Davison had pleaded guilty to possessing or controlling child abuse material, a pre-sentence report indicated that the offender did not believe he had done anything illegal.

Justice Elkaim said viewing such material may strike offenders as a harmless, voyeuristic experience, but in reality every child in the files had been subjected to "humiliation and horror" with long-term consequences.

The court heard that the now unemployed Davison had told a psychologist he was "hoping for a suspended sentence as it is a first offence".

"I want a quick out option, no jail term, so I can leave Canberra," Davison reportedly said.

Justice Elkaim found, however, that time behind bars was "inevitable" for such a crime.

"Children are not pawns or playthings for the sexual gratification of adults," the judge said.

"There are many terrible types of offences but in my view it is difficult to express more abhorrence than in respect of crimes involving children, their manipulation and their degradation."

Justice Elkaim sentenced Davison to nine months in jail, and ordered that the final six months be suspended.