In the course of the job I walked the whole National Trail at least twice, and some parts many times over, but I never did do the whole thing in one go. But I still go out regularly on the Path with my camera, so maybe one day.

Eventually I resigned on medical advice, but then had a amazing stroke of luck. Element Productions, a TV company from Cardiff, contacted the Offa's Dyke Centre in Knighton asking to speak to me about a television series they wanted to make.

Enid Davies at the Centre passed on the message, and I ended up helping Element to sell BBC Wales a 5 part TV series on Offa's Dyke and the Offa's Dyke Path. Iolo Williams and Tessa Dunlop were the presenters and I was series adviser and stills photographer.

Then Zarine Katrak, an old friend, said "Why don't you suggest they do a book too?". So I did. Element showed some of my photographs to Gomer Press and they said yes. And that is how "Offa's Dyke - a journey in words and pictures" came into being.

I started work in earnest on the book in the early 2006, and it took about six months altogether. I actually started with Chapter 5, because that covers my own local area and so was relatively easy. Then came chapters 1, 3 and 2 in that order. Then I got organised, and did the rest in sequence. It was hard work, but also great fun. I actually did quite a bit of the writing sat in the garden with my laptop. It made it feel less like work, and meant I could keep an eye out the jackdaws and swifts which I needed to photograph for the section on wildlife in Knighton. Photographing swifts: now there is real challenge. They don't hang about you know.

I started out with quite a substantial collection of 35mm slides which I had taken as Offa's Dyke Path Officer, then I went out with my new digital camera to fill in the gaps.

The finished book contains 300 colour photos, two-thirds of which were new digital ones. Mairwen Jones at Gomer edited the book, and between us we chose photos which we felt best represented the path, dyke and landscape, and which fitted the layout.

Mairwen was particularly good at choosing pictures which looked good together, whether on a page or in a chapter. I would take my laptop along to a meeting with Mairwen and we would sit over it sifting through pictures in Photoshop.

Every so often Mairwen would say "I want that one!" Between meetings she would ring me from time to time and say "Have you got a picture of ....." If I had I would e-mail it to her. If I had not I would go out and see what I could find.

On one occasion she wanted oak leaves, and though I was laid very low with asthma I sallied forth and found some. Actually I cheated slightly with that picture: I cut a sprig of leaves and brought them home to photograph in a jam jar on the windowsill. Then I turned the picture upside down so that they looked as though they were hanging from a tree. The confessions of a fraudulant photographer.

I was taking pictures to order right up to 12th October, and the book was published on 1st November.

For twenty years I used Olympus OM series, which take 35mm film. I put off switching to digital until I felt the quality could match these, and after very careful consideration chose Olympus again, this time an E-1 with a range of zoom lenses. They were not cheap, but they are good.

I would like to do another book like this one, but I am not going to say too much about my ideas yet, in case someone else gets there first. My other photographic passion is architecture. Give me a Gothic church and a camera and I am happy. I had another lucky break in March when I landed a last minute contract for the Centre for Architecture and the Built Environment, photographing architectural details for an education pack."

Article written by Jim Saunders.