A man charged with child pornography offences after a tip-off from the FBI prompted police to raid his house has been jailed for eight months.

Gary Michael Johnstone, 54, from Allendale East in South Australia's south east, pleaded guilty to several offences including accessing child pornography and making it available to others online.

The District Court heard he emailed a woman he believed was sexually abusing her daughter and asked her to take pictures of the girl for him.

Johnstone also contacted an 11-year-old girl from Sydney through an internet chat site, asking her sexually explicit questions and encouraging her to send him photographs of herself.

The court heard police were unable to locate the girl but found evidence of the online conversation when they raided Johnstone's home and analysed his computer equipment.

They also located 658 images and 33 videos of child pornography, 75 of which were placed in the worst two categories.

The court was told Johnstone worked as a panel beater.

It heard he started looking at child pornography when he developed depression after the death of his mother in 2000.

The court heard Johnstone had never married or had a girlfriend and felt socially isolated.

He also suffers from a neurological condition affecting his face and has been diagnosed as being in the early stages of multiple sclerosis.

Judge Paul Cuthbertson acknowledged Johnstone had been seeking treatment for his sexual attraction to children but said the offences warranted an immediate prison sentence.

"The depth of your depravity is illustrated by an email you sent on the 22nd [of] March 2009, which wasn't the subject of any charges, to [a woman called] Warja," he said.

"Having knowledge she had a young daughter whose photographs you had seen, you said 'Well you're amazing, I've never heard of or seen a woman who would do this with their daughter'.

"Indeed, it may well gave been amazing that a woman should subject her daughter to such depravity, but you encouraged it."

Judge Cuthbertson sentenced Johnstone to two years in jail but ordered he be released after serving eight months.

Johnstone will then be subject to a 15-month good behaviour bond.