Colin Prior has shot so many iconic images of Scotland, by what's next for him?

Colin Prior once stood on the early-morning summit of Sgurr na Stri in the Skye Cuillin.

The sun was starting to climb high into the sky. Around him were the cloud-dusted Cuillin peaks.

All was silent. It was a serene, stirring, absorbing sight. Suddenly, the air was filled with the bright chatter of cuckoos, calling to each other from across the tops of summit cairns.

For 15 minutes this went on, and it awoke in Prior a feeling of euphoria - a sense of utter fulfilment, of what it is to be alive.

Over the years, Prior has trekked hundreds of miles through remote Scottish countryside and scrambled up rocky mountainsides, often in pitch-darkness, as his wife and two children slept at home.

He has startled herds of deer and wild goats on his pre-dawn journeys, he has been eaten alive by midges, he has seen pairs of golden eagles soaring through the air and peregrine falcons zipping past him at astonishing speeds.

And on all of these journeys he has been carrying up to 52lbs of camera and other gear on his back.

Now 200 of the best of his photographs of Scotland, taken between 1990 and 2013, have been assembled for a magnificent volume, Colin Prior:

The Collector's Edition - Scotland's Finest Landscapes. From the Hebrides to the Cairngorms, Knoydart, Assynt and Torridon, they are otherworldly, panoramic shots that take the breath away.

Leaf through it, and you will have your favourites - mine, at the moment, is a picture taken at sunset on Rannoch Moor almost exactly six years ago: a wintry shot of Clach Leathad and Meall a' Bhùiridh, the trees and the boulders and the hillsides covered in snow, the rays of the setting sun slanting over the entire landscape, giving it an ethereal air.

"It's a retrospective, really," Prior says of the book. "It's the best of the images that have been published in the last three books (Scotland: the Wild Places, The World's Wild Places, High Light - A Vision of Wild Scotland), as well as some new work.

"That period of time where photographers captured images on film, that window has almost closed.

"I've been working digitally for many years.

The hassle factor of using film through these wide-format cameras, couriering the film to and from London for processing, and sending them off back to London to get them scanned … just to get an image of your screen was a lot of work. Things have moved on.

"In many ways, the new book will give me some closure in working in that format.

It has taken me more than 30 years to get these images from the mountaintops, but in my time I have shot most of the big pictures from Scottish mountains that I want to shoot - once you've done it, you're not really inclined to go back.

"I've only ever done that a couple of times, because of the time and the sheer physical effort involved. I feel now I can use my time in a different way - I'm keen to do different things with photography and to work in more conventional formats."

The new, handsomely packaged, 448-page book, which will be available on November 20, has a foreword by Sir Chris Bonington, who describes the photographs as "stunningly beautiful".

Each regional section begins with a map that charts precisely where each photograph was taken.

Prior's next project will see him looking at the landscape "from above habitat perspective" and exploring the habitats of wild birds, many of which have suffered a sharp drop in numbers, due to climate change or loss of habitat.

The project will involve some studio work, and Prior is in the process of talking to a number of museums, some of which have huge collections of birds' eggs.

"What I would like to do," he adds, "is to photograph some of the Victorian egg collections.

I want to use the eggs to categorise the landscape - essentially, to reconnect the eggs to the landscapes.

I'm keen to shoot something a wee bit more intimate with landscapes.

I've been doing test shots over the last six months as well as a great deal of research.

"I want to look at this Victorian fascination with oology, and contrast those times when the eggs were collected and bird populations would have been plentiful, with the situation today, with the RSPB doing so much to reintroduce bird habitats.

"People don't realise just how much birds add to the outdoors experience.

They're perhaps just not aware of what a dull place the world would be like without birds."

He is also engaged in a four-year-long photographic project centred on the Karakoram mountains, a toweringly beautiful region in the north of Pakistan.

He made his first visit there in 1996 and in his own words the Karakoram has "haunted his dreams" ever since.

He returns there next June for another six weeks.

His aim in this project is to create a body of work in celebration of "the most dramatic landscape on Earth".

A book and an exhibition are planned for autumn 2018, it will, all told, be his magnum opus.

In the meantime, Prior is more than happy with his latest book, which showcases his skills as a panoramic photographer.

It showcases, too, his remarkable persistence - trudging across rocky terrains at 1am or through rainy early dawns in search of that perfect moment when light and landscape are in fleeting harmony.

I mention the Rannoch Moor picture - that remarkable wintry shot from November of 2008.

It captures something Prior once said about light transforming the ordinary into the extraordinary, how the results can transcend the landscape and lure the viewer into another state of mind.

He himself has never lost that capacity to feel transformed by what he has seen - to feel, as he did that morning on the summit of Sgurr na Stri, with the sun climbing into the sky and the cuckoos calling to one another from the tops of their respective cairns.

"Absolutely," he says. "It's a great privilege, this job. I try to be in a certain point at a certain time and I'm trying to capture an image which has until then only existed in my mind's eye, for perhaps three or four years."

Signed copies of the new book (£75) can be ordered from www.colinprior.co.uk