Story highlights Robert Freeman was favored snapper of Beatles between 1963 and 1965

He photographed and designed five consecutive Beatles' album sleeves

Exhibition of his collection on display in London for first time in 20 years

Prints include only example left of one ultra large "Rubber Soul" print

The first solo exhibition in about 20 years of early photos of the Beatles taken by a British photographer who designed five of their UK album covers is on display in London.

Robert Freeman photographed and designed the Fab Four's second to sixth album covers and was the group's favored snapper for three years between 1963 and 1966 in their early and middle stages of fame. Freeman also traveled with the band on their momentous first tour of USA in 1964 when Beatlemania first spread across the Atlantic.

Freeman, who is now in his 70s and lives near Seville in Spain, sold his entire Beatles collection to rock 'n' roll photo curator and agent Raj Prem many years ago.

The 58-year-old Londoner has put up a solo exhibition of Freeman's work at Snap Galleries in Piccadilly Arcade, London.

"Someone gave me Freeman's number in Spain and I contacted him and flew over to see him," Prem says.

"I was so impressed by his collection of Beatles photos that I kind of did a deal and gave him some money and bought the entire collection. The increasing scarcity of the prints is making them go up in value all the time," he adds. "I did not know when I bought them that they would go up because I was at the beginning of my career -- I had no idea at all," says Prem.

Freeman made no more than 25 editions of each print and many editions are now almost sold out. He is not making any more prints, so for some of the photos on sale, there is just one example left -- signed and numbered by him.

"He was very close to Lennon," Prem says, explaining that Freeman even lived in a flat below Lennon in London for one year. Freeman also photographed and designed the covers of John Lennon's first two books, "In His Own Write" and "A Spaniard in the Works" too.

According to Prem, Freeman described Lennon as "highly creative, very witty and a very surreal person -- the most interesting of all the Beatles."

"But he did say to me once that he found Ringo Starr the most interesting to photograph as he's got a large nose and a face with a kind of pathos. He always said Lennon was the best looking," he adds.

After graduating from Cambridge University in 1959, Freeman became a photographer working for the Sunday Times and various magazines.

It was moody black and white pictures he took of John Coltrane at the London Jazz Festival in 1963 that impressed Beatles manager Brian Epstein that led to his first commission -- to shoot the cover of the Beatles' second album, "With the Beatles." It is now one of the most famous sleeves in rock music.

He proceeded to photograph the next four consecutive Beatles' album covers -- "A Hard Day's Night," "Beatles for Sale," "Help!" and "Rubber Soul" -- all considered seminal and ahead of their time compared to LP designs at the time. Some covers, like the music, were modified for the U.S. market.

"Freeman was not the only photographer who took pictures of the Beatles but he was the only one who worked with them for a continuous period of three years and he was their favorite photographer during that time," Prem says. "He toured with them. He was obviously a trusted confidante."

Freeman also shot many other rock stars and photographed the first ever Pirelli Calendar in 1964, but according to Prem his work with the Beatles "overshadowed everything else he ever did." 'With the Beatles' shot him to fame," Prem says. "'Please Please Me' was a very anodyne shot and was not so easy to recall as the following album." He puts the "With the Beatles" album cover among the top three Beatles album cover designs of all time, the others being "Abbey Road" and "Sgt. Pepper's Lonely Hearts Club Band."

Freeman also took many other portraits of the boys in different settings capturing their individual personalities and he designed the opening and closing credits of the comedy films "A Hard Day's Night" (1964) and "Help!" (1965), both of which starred the rock group.

But when his proposal for the sixth album, "Revolver," was rejected, he pretty much stopped working with them after that, Prem says. "I don't think he was upset -- he felt it was inevitable. I don't think he stayed in touch with the Beatles after that. He continued with his other photography."

But he recalls: "Freeman was living in Hong Kong when Lennon was assassinated in 1980 and he told me that he had a photo of Lennon on his wall and it fell down at exactly the same time."

"What makes the Beatles unique is that their appeal is not purely nostalgic," Prem explains. "The Rolling Stones mean little now to anyone under the age of 30 whereas the Beatles are probably bigger now than they were at the time. When they went over on their first tour to the USA they got what was then the biggest audience in the history of American TV when they appeared on The Ed Sullivan Show, " Prem adds.

Japan and America are his biggest customer market for this collection, which has prints priced from $1,500 (£1,000) upwards.

"We've had a fabulous reaction from Beatles fans," says Guy White, the director of Snap Galleries.

"We've had all age ranges and people from all round the world coming to see us. As soon as the show went up, we found that all the Beatles and rock 'n' roll tours of London were including the gallery on their itineraries. We've had fans alongside serious collectors," he says.

"His five covers are so interesting because, putting it simply, they show five completely different ways of portraying four heads in a 12-inch square."

The most expensive print on sale is an ultra large size sepia print of Rubber Soul, the only one left the world, which is up for sale at $45,000 (£30k.)

In his coffee table book, The Beatles: A Private View, Paul McCartney is quoted as saying of Freeman's work: "I have a feeling that Bob's photos were amongst the best ever taken of The Beatles."

The exhibition Robert Freeman: Beatles for Sale continues at Snap Galleries, Piccadilly Arcade, London, until March 16, 2013. All the prints are from the Raj Prem collection.