Graham had pleaded guilty at a previous hearing to nine representative charges – six of possessing and three of distributing computer photo and video files which depicted sexual abuse and exploitation of children as young as six months.
The charges related to more than 4700 files, held on a phone or on social media or cloud storage accounts, which came to the attention of the Department of Internal Affairs after it was tipped off by law enforcement agencies overseas.
Graham's offending began when he opened a chat group account in 2014, but mainly occurred in the years 2017 to 2021.
Counsel Michael Blaschke, prosecuting for Internal Affairs, said some of the material depicted the "most serious and depraved offending against children".
He said the files had been categorised with a high level of organisation and shared in direct communication with other people online – Graham had "distributed material that he has viewed as the best ones".
The court has been told that some of the files in Graham's collection depicted the graphic sexual abuse of infants.
Others showed very young children being tortured or abused by, or in sexual activity with adults or other children.
One of the extreme files in Graham's collection was a video of a girl aged about 12 months which had been created by Australian Peter Scully, who operated a pay-per-view child pornography website and was sentenced to life imprisonment in the Philippines in 2016.
Graham used a photograph of a teenage girl to connect with people online. Once, when challenged by another user about his fake profile, he said he used it "so people will actually talk to me".
Graham had shared other photos of the young woman. She read a victim impact statement to the court via audiolink on Thursday.
Judge Nicholls thanked her, acknowledged her bravery and said it was important to have a voice for the victims of Graham's offending in court.
He suppressed the statement's contents, along with all details which would identify her.
Defence counsel Cam Robertson said Graham had no previous convictions of relevance. His offending had started at a young age and gone "largely unchecked".
Graham's mother died when he was young.
The charges against Graham were filed by Internal Affairs under the Films, Videos and Publications Classification Act 1993, which deems material that promotes or supports the exploitation of children for sexual purposes an objectionable publication.
"This man is a significant offender and this period of imprisonment will ensure that he is unable to access or trade images of child sexual abuse," the manager of the department's Digital Child Exploitation Team, Tim Houston, said in a statement reacting to the sentence.
"Images of child sexual abuse are the result of real children being sexually abused and exploited," he said.
"Those who distribute these images need to bear a direct responsibility for the original abuse, as well as being responsible for encouraging the production of more images and more abuse of victims."
The judge ordered that the equipment Graham used to commit the offences be destroyed.
