Most people in the area were sheltering indoors as Super Typhoon Dujuan slammed into northeast Taiwan late on September 28, but Hong Kong-based James Reynolds was in an alcove next to the railway station in Suao township, near the coast, filming as debris crashed by.

Just behind him, keeping an eye out for danger, was his friend Mark Thomas, who noticed metal roofing sheets smashing so hard into concrete that sparks flew. Branches were swept past as the wind roared, fierce rain squalls reduced visibility to less than four metres.

"Dujuan was in the top three strongest typhoons I've filmed," says Reynolds, which is saying something given that, at just 32, he's a veteran of "chasing" and filming typhoons. Although storm chasing is not unusual in the United States, Reynolds is a pioneer when it comes to hunting typhoons - the Pacific equivalent of hurricanes or cyclones - and Dujuan was his 51st.

In a decade of typhoon chasing, Reynolds has turned what began as a hobby into a business, appearing on global news reports and licensing footage for productions ranging from wild weather documentaries to screwball disaster movie Sharknado. Not content with heading to storms most people wish to avoid - including Haiyan, which killed more than 6,300 people in the Philippines two years ago - he has added volcanoes to his repertoire, filming as ash clouds race down slopes towards him or a quivering lava dome threatens to disintegrate and obliterate the surroundings, including Reynolds.

REYNOLDS GREW UP IN Gloucestershire, southern England - hardly a place for nature's extremes, though he remembers loving autumnal storms and "lying in bed listening to the wind and rain. It was a very comforting feeling".

His father was an airline pilot, and the family made the most of the cheap flights that entitled them to.

"I got captivated by this part of the world," says Reynolds.

In his late teens, he set off on what was supposed to be a round-the-world trip, but spent most of the time in Southeast Asia - Thailand, Vietnam and Cambodia - riding scooters and enjoying cheap beer on the beach.

Then, as a "ticket back to Asia", Reynolds studied Chinese at the University of Edinburgh, in Scotland. The course included a year in Shanghai and a stint in Taiwan.

"I was in Taiwan during July and August, and it was clobbered by two very intense typhoons," recalls Reynolds. "It was my first taste of extreme weather and my expectations were totally off. I expected crazy raging wind, but there were strong outer bands in Taipei, and I got the idea about typhoons, including that as you get closer to the centre, winds increase exponentially in strength. I was fascinated about getting into the eye of a storm, to see what it's like, experience the strongest winds on Earth."

After graduating, Reynolds landed work with a television production company in Shanghai, helping to make documentaries and news stories.

His first solo chase was in September 2006, when, equipped with a basic handycam, he travelled to a small town near Da Nang, on the Vietnamese coast.

"It was quite expensive and I stressed about the cost of the trip," he says. "But it seemed the right thing to do - it was unusual and interesting. I blundered in with no idea of what to expect, assuming the storm would come to me based on the Joint Typhoon Warning Centre information. I went to a hotel and waited, with my dad sending text message updates."

The hotel was one of the tallest buildings in the town, and Reynolds went to the covered roof to observe the typhoon come in. He watched as the wind blew, rain lashed, windows shook, as the area was clipped by the storm's southern eyewall. Some tourists yelled at him, "What are you doing on the roof?", he recalls, but, as he left the hotel, the staff thanked him for having kept them updated on the typhoon, which they'd underestimated.

Typhoon Xangsane caused extensive flooding and 71 deaths in Vietnam. Reynolds was shocked to see the damage, especially from the storm surge, which had dumped sand over the main coastal highway. Walking through knee-deep floodwaters, he filmed a row of seafront buildings that had collapsed and a radio tower that had fallen on a house.

A German company that was making a documentary on typhoons asked to use some of Reynolds' footage. They paid £250 (HK$3,000), but Reynolds says he thought that would be a one-off, when it came to monetising his new hobby.

Watch: Exploring the force of mother nature: a typhoon chaser's story

Then in 2007, "I got into really meaty storms, and some things blew my mind," Reynolds says. "I realised documenting this stuff was really interesting and important."

One of those storms was Typhoon Sepat, which hit central Taiwan in August that year. Although Reynolds experienced powerful, eyewall winds, he was most impressed by the immense water runoff, particularly at the foot of a gorge where a normally placid river had been transformed into a surging brown torrent.

The next spring, he was interviewed about Sepat for Discovery Channel's Raging Planet series. The interview in Taiwan was - appropriately enough - delayed by a typhoon.

Up until this point, Reynolds had filmed on his handycam. Now rating the footage "dreadful", he bought a basic video camera, gave himself the moniker "typhoonhunter" and set up a YouTube channel.

He licensed more footage to documentaries and, in 2009 - with exposure through Twitter - news agencies started approaching Reynolds; he appeared on segments for the Weather Channel and CNN.

In early 2009, Reynolds moved to Hung Hom, in Hong Kong, with wife Yoki, a Chinese woman who had grown up in Japan and whom he had met during a language course. He began marketing his footage but Yoki was initially sceptical he could make a living from it. She now appreciates that he's in the rare position of being able to do something he loves as his job - and trusts that he knows how to protect himself.

"I have no interest in chasing storms or volcanoes," Yoki says. "I prefer visiting the locations he goes to when the sun's shining."

Reynolds did find a partner, though: Thomas, a Taipei-based British businessman who shares a fascination for natural phenomena and love of travelling. They met at the Mayon volcano, in the Philippines.

"One of the weird things about James and I is that we have almost the exact same level of danger/safety awareness," says Thomas. "A chase is only 20 per cent about the 'phoon or the 'cano. Mostly, we just have loads of laughs and share quite a few beers."

"We watch each other; make sure we get into safe places, which with typhoons basically means lots of concrete, safe from the wind," says Reynolds.

Although Reynolds aims to be mentally prepared for the devastation he witnesses, he was still shocked to film a man being swept to his death. The incident was all the more startling for occurring during fine weather; Reynolds had been filming huge waves created by a nearby storm as they pounded a craggy headland on one of Japan's Ryukyu Islands. A fisherman walked into the frame, went briskly down a steep path, put down his gear and, seconds later, was swamped by a wave. Reynolds was unable to do anything to help.

The next year, Reynolds was filming waves hurtling through a harbour in Taiwan. Seeing a fisherman panic and leap from his boat, then struggle in the swell, he ran forward - camera still rolling - and pulled the man to safety.

"My mantra is: if you do what I do, you need to have a positive effect on the communities where you're filming," says Reynolds. "They're having a really bad day, and if you can help out - great."

Even so, storm chasers such as Reynolds do face criticism, particularly because the weather they relish often causes death and destruction. After witnessing Typhoon Haiyan in the southern Philippines, Reynolds wondered, "Am I a ghoul going in?"

But on later returning to the worst hit town, Tacloban, he and Thomas were welcomed. The hotel they stayed in had strung up a banner, "Welcome to the Typhoon Team".

People appreciated their efforts, says Reynolds, and felt they'd filmed the storm well, and got footage out quickly. A doctor said, "Thank you, guys. We knew it was bad, but it was not until we saw the footage that we really grasped how catastrophic it was."

Haiyan had looked set to be powerful even as Reynolds left Hong Kong in early November 2013. He and Thomas, along with American storm chaser Josh Morgerman, first booked into a hotel by the shoreline in Tacloban. But checking online information, they realised they had made a mistake.

"We were seeing images no one had seen before in the modern satellite era," says Reynolds. "There was a forecast of 170-knot winds, crazy s**t like that. Twitter was abuzz with meteorologists saying this was one of the strongest storms in recorded history."

The trio warned the hotel staff of the impending danger and found a hotel at least two blocks inland and five metres above sea level. They spent a night there with Haiyan approaching but, even as dawn broke on November 8, the winds were still little more than breezy. Then, abruptly, the core of Haiyan arrived.

Reynolds filmed from a balcony as wind and rain lashed the town's rooftops; soon water was pouring down the hotel stairwell. The situation became scary as brown water rose to knee height, and kept on rising. The ground floor of the hotel was transformed from sanctuary to potential death trap, with some people trying to escape rooms, others arriving from outside. The three storm chasers became impromptu rescuers, carrying a wheelchair-bound man up a flight of stairs and wading through waist-deep water to guide others to safety, including two who were on mattresses that were being used as floating stretchers.

Reynolds filmed as best as he could while he helped others. He warned Thomas to be careful of debris in the filthy water but his friend was struck by metal, which penetrated his ankle and ripped a gash in his lower leg.

The typhoon's onslaught was over by late morning. On seeing the devastation wrought by the storm surge, Reynolds knew immediately he was in the middle of a disaster zone. He filmed as debris filled streets between ruined houses; as people discovered bodies among the wreckage; as a man tossed a bowl of water at a shop that had become a raging inferno.

Luck was on the trio's side, as the Philippine army set up a command post close to their hotel. They were evacuated by helicopter and then a flight from Tacloban. Thomas, whose wound was starting to rot, received treatment just in time.

"The doctor said if there had been another 24 hours with no medical care, he would have lost his leg," says Reynolds.

The emotional impact of what he had witnessed hit Reynolds later, especially during a visit to a Tacloban graveyard.

"Mass graves were the worst," he says.

As well as having covered Haiyan for news agencies, licensed footage of the event and recounted his story for documentaries, Reynolds has given footage of Haiyan to more than 50 charities and other organisations, hoping it can forewarn people should similar storms threaten.

Filming volcanoes was, for Reynolds, a logical extension to storm chasing.

"With so many amazing volcanoes almost on my doorstep, it would seem silly not to go after them," he says. "Volcanoes interest me as much as, if not more than, typhoons do, and to see a full eruption is quite rare. They're scarier than typhoons, though, with a lot more opportunity for things to go wrong."

In October 2010, he headed to Central Java, where Mount Merapi ("fire mountain") was in the midst of multiple eruptions that would kill more than 300 people. Reynolds shot steam and ash being blasted from the summit crater and a nearby city and village coated in ash. The volcanic island of Krakatoa, in the Indonesian province of Lampung, was also "popping" at the time. Reynolds set up camp on a beach about 1.5km away, filming some of his best volcano footage yet, with ash and lava bombs exploding from the crater, looking grey by day, glowing red at night.

Two months previously, Reynolds and Thomas had gone to Mount Sinabung, in Sumatra, after it had erupted for the first time since 1600.

"We spent about five days there, and saw nothing," he recalls. "But four years later, it really started cranking up, and we knew exactly where to set up, which hotel to stay in."

On January 21 last year, Reynolds filmed as a monstrous ash plume billowed skywards and pyroclastic flows raced down the volcano's slopes.

Pyroclastic flows are like avalanches of ash and rock and, with temperatures of up to 700 degrees Celsius, they are deadly to everything in their path. Just 11 days after Reynolds filmed at Sinabung, a television journalist was among at least 16 people killed by an eruption.

Reynolds and Thomas had chosen their vantage point partly because they could see locals still farming nearby, and there were two ravines between them and the volcano. Even so, a gentle rain of ash fell on them, and shots taken with a telephoto lens show foaming, dull-brown surf surging down barren slopes, looming so large in the frame it looks barely an arm's length away.

"My heart was racing on one or two occasions," says Reynolds. "You see a force like that, and can't help but have your heart racing. It's an amazing volcano."

Reynolds has filmed volcanologists abseiling into an active crater but, he says, "I'm not interested in doing stunts myself; I'm interested in getting shots."

Even so, he often ventures where many people might tremble to tread.

In November 2012, 196 people who lived on Paluweh, an 8km-wide volcanic island in eastern Indonesia, were evacuated to nearby Flores. A dome of lava had been building in the crater - the volcano often puffed out ash - and, on February 3 the following year, an eruption blasted ash 14km skywards, creating a plume that eventually reached west Australia. Days later, Reynolds and Thomas arrived.

It was the rainy season and, due to downpours and mists, the intrepid duo saw the volcano for only two of the 48 hours they spent on Paluweh. But while mostly out of sight, the volcano was never out of mind.

"There was an earthquake every 15 minutes - the whole mountain was shaking," says Reynolds. About 70 per cent of the island was atop the lava chamber, a guide told Thomas.

The one time the weather cleared, they climbed the volcano and looked over a ravine to the active lava dome. This was a great bulge, perhaps 100 metres high, with molten magma pushing upwards inside, covered in only a thin crust of hot rock that occasionally parted to reveal the glowing red core. Reynolds filmed the unstable, trembling steep slopes, which were steaming as if a fire raged within. Rock falls were frequent, with boulders bouncing and skidding downhill.

"I think it was the craziest place I've been - watching bits breaking off," says Reynolds. "There was always a chance of an explosion, and the mountain was shaking. It was like Jurassic Park up there.

"I probably wouldn't ever go near a dome like Paluweh's again.

"That was scary."