A pensioner had more than 17,000 indecent images and movies of children, including a 12-month old baby being sexually abused, when police raided his Leeds home.
Ernest Blackburn had accessed some of the most serious and grossly offensive material which included images of animals being sexually abused.
Police made the discovery after searching the married 70-year-old’s home in Colton.
Leeds Crown Court heard officers went to his home on Austhorpe Avenue on September 2011 after receiving information.
Blackburn continued to deny an offending, claiming he did not know how the material got onto his computer.
He eventually pleaded guilty to 21 offences related to possessing or making indecent images of children on the day he was due to go on trial last month. More than 900 of the illegal images were at levels four and five - the two momst serious categories of offending.
A judge ordered Blackburn to spend the weekend in prison while he considered what sentence to impose when he appeared in court last Friday.
After being returned to court he was made the subject of a three-year intensive community order designed to address his offending. Blackburn was told he must also go on the sex offenders register for five years.
The court heard Blackburn had no previous convictions and had shown remorse over his offending.
Blackburn’s lawyer Ian Cook said the short spell in prison had been a frightening experience for his client.
He added: “The reality of prison life is a lot worse than he has seen on TV.”
After the hearing, Det Con Claire Forder, of West Yorkshire Police’s abusive images unit, said: “Today’s sentence sends out the message that individuals who exploit children via the internet will be identified and prosecuted.
“West Yorkshire Police are committed to tracing such offenders whether within our county or beyond.”