Alex Aitchison always keeps his camera at the ready. He's walking for the third time from The Hub - his workplace - down the hill to the Usher Hall concert venue.

During the four-week Edinburgh International Festival, the 23-year-old from Aberdeen will walk that route countless times. He's the festival's official photographer, which is a great honor for the former visual communications student.

"I've been applying for this for three years (…) so it's been a long effort to finally get here," he said.

Each summer, the capital of Scotland transforms itself into the biggest festival city in the world. Around half a million visitors come from all corners of the globe to be entertained by a wide spectrum of artists.

Big stars from opera, theater and visual arts present their talents in Edinburgh. Chinese pianist Lang Lang, dancer Sylvie Guillem, violinist Anne-Sophie Mutter take the stage along with musician Chilly Gonzales and French actress Juliette Binoche in the play "Antigone."

Stars and city profit from each other

For the city of Edinburgh, the festival isn't just a month of cultural fun, but also brings an economic benefit.

"The hotels and restaurants do very well and it's an important part of our economy. But I think that Edinburgh has also been a great center of intellectual life," says Fergus Linehan of Ireland, the director of this year's festival.

Being invited to Edinburgh means you've made it. And that's why Alex Aitchison is so thrilled to be involved. As official photographer, he has unlimited access to all the stages and venues for the nearly month-long event. He says he can now understand just how much work goes into a festival of this magnitude.

Festival photographer's dream job

Around 100 photographers applied for his job. After an initial selection round, the three finalists were put to a test: They attended the official announcement of the festival program and had to deliver their 12 best photographs of the event. The jury like Aitchison's pictures the best.

"There's nothing else like this for a graduated photographer in Scotland. You come out of uni and there's nowhere to go with a photography degree. The one thing you can aspire to throughout your university career is getting this position," says Aitchison.

'It brings people together'

Today, Alex Aitchison has an important appointment. In Usher Hall, the big opening concert with BBC Scottish Symphony Orchestra and the Edinburgh Festival Chorus is taking place, in celebration of the choir's 50th anniversary.

Choir member and soprano Clare Hewitt is participating in the festival for the fourth time and it's always a big highlight for her. "It connects in a way that it draws people from around and draws musicians from around the world who are invited to perform at the festival," she says. "And for the chorus to be working with those people as well makes it extra special."

No pictures are allowed to be taken during the concert. Alex Aitchison has to wait until the event has come to an end. He quickly changes his memory card. He has just a few seconds to snap the perfect photograph - and he has to make the most of it.

Snapping the perfect shot

Click. Aitchison takes his photo and rushes off from the Usher Hall to The Hub, his office, past Edinburgh Castle, the city's landmark.

He has no time for a break. He has to process his photos and prepare for the next shoot. But he says it's worth the stress - after all, he's going to end up with an incredible portfolio.

Alex Aitchison collects everything he gets his hands on: tickets, press passes, brochures. He wants to have a few souvenirs from the best job in the world - beyond his own photos.