In the four years since the Mighty Boosh performed their last tour together, comedy has become anaesthetised by the likes of Michael McIntyre and Miranda Hart. Next month, then, is something to celebrate for those of us who like our comedy dark and dangerous: the Boosh return in spirit in a London photography exhibition and on stage in the US. It's about time. Their escapist silliness has been missed.

When Noel Fielding and Julian Barratt, the principal members of the Mighty Boosh, started doing gigs in 1997, they had decided to be the new Goodies. It was a flip reference to the zany 70s show; their own successful BBC series owes more to The Goon Show, Tony Hancock, Monty Python and Vic and Bob. Like all double acts, the Boosh are an odd couple: Fielding, with the glam rock hair, gold boots, flea-market coats and persistent grin, and Barratt, the tall, laconic jazz fan. They were escapist and surreal – although they always dispute being surreal – when most other comedians were hellbent on being naturalistic.

The Boosh's rock-star cool has ensured a devoted fanbase that has grown up with them. Dave Brown, who met Fielding at college, and sometimes appears with the Boosh as Bollo the gorilla and has taken more than 10,000 photos of them, says the fans are loyal "because Noel and Julian were never in it for the money. They were offered huge amounts for ads and merchandising, but it was always about the comedy."

Last year, Brown had an exhibition, Tough Crowd, showing the darker side of comedians (a pensive Jimmy Carr; a tough Bill Bailey). After its success, Proud Galleries asked him to collate his best Mighty Boosh photos from their stage shows and BBC series. Do they too have a dark side?

"Julian is more intense than Noel, who is very light and breezy. Noel wants to have a good time and be everyone's friend. He's always happy to pose for the camera. Julian is a lovely guy, but people often get a cold feeling from him. He doesn't like having his photo taken so tries to talk and eat his way through sessions. And then complains when he looks terrible…"

These days Barratt is a devoted family man (he has young twins, Arthur and Walter, with Julia Davis), also a comedian, while Fielding has never tired of being a cool man about town. With his stack-heeled boots and natural flamboyance, Fielding appears to be several decades late for an audition with Sweet, but Brown remembers their first day at college. "Noel wore a baggy check shirt, had long hair and looked like Evan Dando. We were both obsessed with Pearl Jam and Nirvana. I looked equally pathetically awful. We were both comedy trainspotters."

Their nerdiness still seems to be paying dividends more than two decades later. By chance, just before the Proud show opens, the Mighty Boosh have been invited by Jack Black to play festival Supreme on Santa Monica Pier – and they'll do some warm-up gigs in this country. Brown insists they never split up, just went off to pursue solo projects – Fielding to record the E4 show Luxury Comedy and Barratt to play a werewolf in Being Human – but it does feel like a comeback gig. Their return is certainly eliciting a fanfare; organiser Black told Rolling Stone that The Mighty Boosh was his "favourite television show to come out the UK since Monty Python's Flying Circus".

Brown, who will be joining the Boosh on stage, is crackling with excitement. "We've been away for four years and now we're about to play to 20,000 people in California. When we went to New York in 2009, fans were chasing the car down the street."

For those lucky enough to be in Santa Monica on 19 October, it will be like the comedy Beatles were never away. For the hardcore fans who manage to get tickets up for the warm-up shows, it will be a tantalising look at where Fielding and Barratt might go next if festival Supreme goes well. For everyone else, Brown's intimate behind-the-scenes photos will remind us of the Boosh's inspired silliness.