Le Cardinal d'Amboise': One of the Niépce heliographs to be seen in Bradford
Three of the world's oldest examples of photography have gone on display in Bradford in what's described as a once-in-a-lifetime chance to see them.
The photographs were created by Joseph Nicéphore Niépce, the man seen by many as the world's first photographer.
The artefacts are on show at the National Media Museum in the city.
Museum curator Philippa Wright said: "That they will all be on public display out of their frames for perhaps the last time is very special indeed."
Christ Carrying His Cross: A Niépce heliograph on pewter from 1827
Joseph Nicéphore Niépce was an amateur scientist who collaborated with fellow Frenchman Louis Daguerre on various image-making techniques in the early 19th century.
Niépce created images on several plates and brought them to England to show off his techniques in heliography - a process which is a forerunner of modern photography.
Recent analysis has led experts to conclude these three artefacts, which were made on pewter plates, are among the finest examples of Joseph Nicéphore Niépce's works.
Sadly, Niépce died in 1833, leaving Louis Daguerre to publicly reveal photography to the world in 1839.
It was Daguerre and the English inventor William Henry Fox Talbot who went on to be regarded as the founders of modern photography.
Philippa Wright, the National Media Museum's curator of photographs, said: "The fact these photographic treasures are part of the National Collection of Photographs which is cared for here in Bradford is quite amazing."
The three Niépce photographs which are on display are all part of the Royal Photographic Society collection at the Media Museum.
They are on show during a two-day conference where recent advances in scientific, art historical, and conservation research are to be revealed.
The research has been carried out both by the National Media Museum and the Getty Conservation Institute in Los Angeles - one of the world's leading authorities in the conservation and research of the visual arts.
Dr Dusan Stulik, senior scientist at the Getty Conservation Institute said: "Our findings are shining a different light on the early history of photography than has been previously described in literature.
"This is very exciting as we have been able to create a fuller picture of Niépce and how he worked.
"We can really demonstrate that everything related to photography that surrounds us today - digital cameras, film, TV, even 3D and video games - go back to his inventions."
Conference delegates visiting the National Media Museum between 13 and 14 October will be given a unique opportunity to closely examine three of the plates created by Niépce.
The plates can then be viewed by appointment at the museum until the end of October 2010.