Simon Murphy has documented human rights abuses in countries including the Democratic Republic of Congo, South Sudan, Ethiopia and Colombia.
But nothing prepared him for a trip to Bangladesh with the Scottish Catholic International Aid Fund (SCIAF).
The charity has so far helped more than 40,000 families who have fled Myanmar.
But Simon, from Glasgow, told how many have been left traumatised after witnessing atrocities ranging from sexual violence to mass murder.
He said: "One girl I photographed saw her parents being killed.
"Others told how they had witnessed villages being torched, children being raped and families being butchered with machetes.
"The Rohingya have lost so much and their experiences are beyond comprehension."
Shawkat Ara, 38, hid in the jungle and watched her village burn after it was attacked by soldiers in the middle of the night.
She said: "The military told the young boys to stand in a line and told them to run.
"When they were running they rushed them from behind and they were falling in ditches.
"Some were cut into pieces and thrown into ditches.
"They were all between 10 and 12 years old.
"The military were actually playing with the boys.
"They were telling them to run and then cutting them."
Although she survived the slaughter Ms Ara, who is five months pregnant, lost her son and parents to hunger as the family fled.
Despite a recent agreement with the Burmese government for repatriation, refugees continue to arrive in Bangladesh.
But Mr Murphy said the situation facing those who brave the dangerous border crossing is desperate.
He said: "New arrivals are taken to a reception area near the harbour.
"They are tired and hungry and have witnessed unspeakable horrors but they have to stay in wooden pens until they are processed.
"It can take up to 48 hours for this to happen and there is a real sense of hopelessness."
Conditions in the camp are also bleak and there are genuine fears about what will happen when the heavy rains come.