It was the Scottish house where light became photographic art.

Now Rock House, a property on Calton Hill in the centre of Edinburgh, where in the 1840s the Scottish photographic pioneers David Octavius Hill and Robert Adamson created their ground-breaking imagery, has been sold for more than £1.7m.

Built in the 1750s, the house became part of photographic history when in 1843 Robert Adamson moved into the property, followed by his business partner and artist, Hill, in 1844.

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The "most famous address in photography" was sold to a private buyer this week, after it was put on the market for offers over £1.795m in June last year.

At the house - which has been sold after months of "great interest" from potential buyers, according to estate agents Knight Frank - Hill and Adamson produced their calotype photography.

Their images, described once as 'painting with light' has been compared to the works of Rembrandt.

Hill and Adamson created thousands of calotype portraits, views and landscapes - more than 5000 of their images are held by the National Galleries of Scotland.

Their key work included capturing the likenesses of the 450 ministers who had seceded from the Church of Scotland in the Great Disruption to form the Free Church of Scotland, as well as images of the fishing village of Newhaven and its workers.

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The elevation and clear light available at Rock House was useful for several reasons, according to Anne Lyden, international photography curator at the National Galleries of Scotland, which is holding a major Hill and Adamson exhibition later this year.

Because of its height, Hill and Adamson, and their assistant Jessie Mann, could see whether bad weather was coming, Ms Lyden said, particularly useful as the photographic process in the 1840s was lengthy.

The quality of light was also important as the duo worked outdoors.

She said: "It's an incredibly important place in the history of early photography, it is a remarkable place - when you think of a studio today you think of a controlled interior, a screen, but in those days the walled garden was their studio.

"Most of their portraits sat in that open space."

Adamson died in 1848, but Hill remained at the house with his family until 1869 - his painting In Memoriam: The Calton

shows the house with a camera outside, a reference to his deceased friend and colleague.

Roddy Simpson, an expert on the duo's work at the School of Culture and Creative Arts at the University of Glasgow, said: "Rock House, Calton Hill, Edinburgh, has an unrivalled place in the history of Scottish photography and could be said to be the most famous address in photography.

"But it also represents a continuum of photographic achievement from the very beginning of photography in Scotland and throughout the nineteenth century and well into the twentieth.

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"For a hundred years it was the base and studio for a succession of notable photographers, from Hill and Adamson, to Thomas and John Annan, Archibald Burns, Alexander Inglis, his son Francis.

" A plaque on Rock House acknowledges Hill and Adamson."

The new owner of the house wishes to remain private.

The house was recently redesigned internally by Jonathan Reed, a designer who had worked for figures such as David Bowie, Giancarlo Giammetti and Queen Rania of Jordan.

Edward Douglas-Home, a partner at Knight Frank, said there had been a lot of interest in purchasing the house.

"There was a lot of interest in its history, but also because of its unique location, a rare place for a house to be for sale, and the re-designed interiors too made it a special proposition," he said.