Read more: Where is The Crown season 5 filmed?
In the new episodes, the dramatisation of the Royals hits the 90s and covers Charles and Diana's divorce, his relationship with Camilla, and Diana's infamous Panorama interview with Martin Bashir.
The Wests' screen family is completed by Elizabeth Debicki who takes over as Diana, and Will Powell as a young Prince William.
Speaking about acting with his own child as father and son, West told Yahoo UK and other media: "It was very moving actually, he'd never acted before because COVID stopped any school plays or anything so I'd never seen him act.
"He had this amazing innocence to him that was extraordinary to watch as well as the fact that obviously he's my boy.
"It's very difficult when you act with children to have a physical intimacy, but with him that's obviously not a question which made it much easier."
However, he continued: "But I found when it was more emotional, the scene, it made it much more difficult and you were slightly split in your head between, ok, we're acting this part, but that's a bit weird, isn't it. I'm talking about your mum, but not your real mum.
"So that I found quite difficult, but generally it was really moving and he really enjoyed it. He didn't look like he was, but actually he was loving it."
West has taken over the role of Charles from Josh O'Connor, while Debicki succeeds Emma Corrin.
Talking about her special bond with the young actors playing her screen children, Debicki said: "I loved my kids on the show."
She added: "We've been so incredibly fortunate with the casting of the boys who play William and Harry. They're so new to it, they're so smart and generous and kind.
"I'm so much happier when they're on set with me and as soon as they go, I miss them so much."
Season five, which landed on Netflix today, also sees Imelda Staunton take over the role of the Queen, Jonathan Pryce as Prince Philip, Lesley Manville as Princess Margaret, and Jonny Lee Miller as John Major.
The Crown season five is currently streaming on Netflix.
Watch: Dominic West reached out to King Charles after being cast in The Crown