With 12 studio albums under their belts, it’s hard to imagine U2’s humble beginnings – or even the lead singer Bono without his trademark sunglasses on.

A new exhibition, U2: The Early Years, by photographer Colm Henry, captures the band before they were even signed.

The photographer met them in 1979, at one of their first gigs at Dublin’s Baggot Inn. “They were one of about 600 bands around Ireland at that time and there was high unemployment. Everyone felt that someone had to make it and it turned out to be U2,” recalls Henry, who worked for Irish music magazine Hot Press.

U2, who are headlining Glastonbury this summer, are shown in a new light, long before they became megastars.

Having formed in Dublin in 1976 as teenagers at school, they signed to Island Records and released their debut album, Boy, in 1980. Recording The Unforgettable Fire in 1984 with Brian Eno, at Slane Castle, made a change from the cramped conditions of their previous albums in Windmill Lane, Dublin.

Bono abandoned the cowboy style for a more classic rock star look in 1987, when “With or Without You” became their first American No 1. “Soon they became international celebrities and became somewhat remote, which was necessary for their survival,” adds Henry.

 ‘U2: The Early Years’, Proud Camden, London NW1 (Proud.co.uk) 14 April to 6 June