Billed as a ?photo competition with a twist? is this year?s Photomarathon which takes place in Cardiff on Saturday 13 August, organisers have confirmed.

Open to photographers from all over the UK, participants are given a film with which they are challenged to capture 12 pictures on 12 given topics over a 12-hour period. All they need is a camera and 35mm film.

The aim is to bring ?photomarathoners? together for one day to explore the city and create their own unique record.

?The rules are simple: 12 hours, 12 topics, 12 pictures,? said Danish photographer Betina Skovbro who first brought the event to the UK.

Though prizes will be up for grabs, the event isn?t really about winning, explained Skovbro, adding, ?It?s a chance for anyone with an interest in taking pictures to put their own skills, creativity and sense of improvisation to the test.?

The event takes place from 11am-11pm on 13 August and participants will be allowed to use tripods and flash units.

A shorter, four-hour Junior marathon will be open to children aged 14 and under accompanied by an adult.

The event will form part of Cardiff?s centenary celebrations.

For details and an entry form see