Lerwick Sheriff Court heard how police raided the Mossbank home of Stephen Bell last February.
They found several computers, recording devices and 35 hard drives containing child abuse images.
Bell was jailed for four years and four months.
He was also handed an additional non-custodial sentence of four years, placed on the sex offenders register for an indefinite period, and was issued with a sexual offences prevention order which will closely monitor his future use of the internet.
He had previously pled guilty to the charges, which took place over a five-year period between 1 February 2011 and 1 February 2016 at his home address and elsewhere.
Sheriff Philip Mann told Bell that his offending was of the most serious nature, had taken place over a considerable period of time and was further compounded by his "difficulty in recognising the wrong" he had done.
Procurator fiscal Duncan Mackenzie had earlier described Bell as a man whose life had over time been taken over by obtaining child pornography.
The court was told that the Crown took the decision to fully examine just six of the hard drives, while the remaining 29 drives - which also contained indecent images of children - were previewed.
The forensically examined hard drives revealed more than 100,000 indecent images of children, of which 5,300 were in the most serious category.
Officers also found almost 900 movies with child pornography stored on the devices.
Defence solicitor Tommy Allan described his client as a "loner" who had allowed his obsession to take over his life.
Mr Allan added: "It went out of control, and it was inevitable that at some point it would be discovered."
Det Insp Richard Baird of Police Scotland said: "This was an extremely complex investigation and Bell's system has been described as one of the most intricate ever seen by the specialist computer forensic examiners who worked on the case.
"Possessing indecent images is not a victimless crime and every day children are subjected to dreadful abuse in order to create these materials which are distributed around the world."
A 58-year-old man from Shetland who admitted possessing hundreds of thousands of indecent images of children has been sent to jail for more than four years.