Rankin is buzzing with excitement. The celebrated photographer has set a date for his wedding to Tuuli, who is both a model, and Rankin’s muse.

He reminds me that he disapproves of the word muse, but so gently that it barely feels like a reprimand.

The relationship between the artist and his inspiration is often as complicated as the relationship between lovers — usually volatile and invariably finite.

From Elizabeth Siddal, the Pre-Raphelite poster girl, to rock’n’roll’s femme fatale Pattie Boyd, these passionate attractions have a tendency to turn sour in the end.

Anyone looking for the cracks in Rankin’s love affair, however, will be sorely disappointed. He is as giddy as a schoolboy with a new Instamatic.

“I’ve photographed thousands of models but I’ve never wanted to continue going back to someone,” he says of his fiancee. “ It must be very annoying for her because I always want to photograph her, there’s a shorthand between us and she knows what I want. Because we’re in a relationship she sees that she can trust me and is involved in the process. It’s a different kind of relationship than the normal photographic relationship. I think it’s more about love than anything else.”

He sighs and seems almost deliriously happy. Once famous for his acid tongue — his favourite party trick used to be dismissing the talents of rival photographers — Rankin chooses his words more carefully these days. At the age of 41, he is settled and content. The death of his parents, within a month of each other two years ago, was followed by a period of evaluation.

Falling in love with Tuuli — they have been a couple for three years but first met on a shoot for Elle Macpherson in 2003 — has softened him.

They work together frequently — most recently on a shoot for Macallan whisky in Speyside and a rare opportunity for Rankin to return to the country of his birth — and even when they are not working, his camera is habitually trained on her fine, Scandinavian features. The daughter of a Finnish diplomat, Tuuli Shipster (like John Rankin Waddell, Madeleine Tuuli Shipster cropped her name for professional convenience) is in a similar state of premarital bliss. Working together, she says, has brought them closer.

“We knew each other for a long time before we got together but when we got together I became very nervous about him shooting me,” she says. “When you are in a relationship with someone you don’t want to muck up in any way. He has photographed the most incredible and beautiful people in the world and I felt a bit like a rabbit in the headlights.

“Now I kind of know what he wants out of a photo. Sometimes he doesn’t even say much, we just do it and it’s lovely. I love working with him.”

The Macallan shoot was a true test of their bond. Tuuli spent most of the day naked in freezing temperatures being eaten by midges.

Editor's choice

• Vote for the Breakthrough Award winner
• David Tennant back as Hamlet after back surgery
• Matt Smith is the new Dr Who