That also explains why they are naked in so many of their pieces. 'A lot of times we work with nature. For instance, when we were in the desert, or at Mount Fuji, or on a cliff, if we were wearing clothes we couldn't have real contact. We needed to breathe - we wanted our bodies to breathe with nature as if they were one,' says Rong Rong (real name Lu Zhirong).

'If we were clothed, we couldn't feel the ambience [of] nature. There would be a boundary and there wouldn't be real interaction. It's about unleashing ourselves, taking off our clothes and opening up and interacting directly with nature.'

Running concurrently with this exhibition is Rong Rong's solo show at the gallery's Central premises, featuring his work between 1993 and 2000.

The couple's story began when Rong Rong took a show to Tokyo in 1999. Already acclaimed for documenting Chinese avant-garde artists in Beijing in his East Village series (1993-1998) and charting the redevelopment of the capital in Ruins (1996-1998), the Fujian native caught the attention of inri, a photographer from Kanagawa Prefecture.

'I found his work very powerful. I liked it a lot and I wanted to interact with him. But we didn't speak the same language, so I used a bit of kanji to leave him a note,' the 38-year-old inri (born Inri Suzuki) says.

Rong Rong recalls reading her words: 'She wrote a few simple lines and I felt her understanding towards me was particularly deep, prompting me to want to get to know more about her. She said she was a photographer too, and I wanted to see her work. So the next day we met in a cafe in Tokyo and she brought along five to six pieces of her work.

'When I saw her photographs they immediately astonished me. I connected quickly with her work - seeing one's work makes you instantly understand what a person's inner world is - and I was pretty sure she was the one I was looking for.'

They stayed in touch after Rong Rong returned to Beijing. In 2000, inri moved in with him and thus began their artistic collaboration. The Japanese photographer believes that despite coming from different countries and cultures, their artistic approaches to photography are similar. 'When we were doing photography alone, I was in Tokyo and he was in Beijing, we were in two totally different environments. But the content of our photographs had some similarities - the rewards of youth, the loneliness of life and suppression,' inri says.

Rong Rong adds: 'But after we worked together, the extreme loneliness, suppression and struggle obvious in inri's and my earlier work were gone and turned into something else.'

Today, they look at the world through what they call the 'third eye'. Instead of standing behind the camera and using photography to express their own feelings, they take in the world from in front. This approach has parallels with the teaching of ancient Chinese philosopher Lao Tzu in which 'the Way begets the one, the one begets the two, the two begets the three, and the three begets the infinite'. It means that by opening their scope, they also expose themselves to endless artistic possibilities. In the Great Wall, In Yulongxueshan and In Bad Goisern are good examples of this newfound freedom.

The Liulitun collection (2000-2003) - including Liulitun, Beijing 2002 No8 (2003), a photograph of the couple sitting in the ruins of their house with a big bunch of lilies - takes on a gloomier tone, mourning a home that will be demolished.

In Liulitun, Beijing 2002 No 1 (2002), the couple sit naked on a bench in their garden, Rong Rong says, 'to show that we and the house are one' and to express their strong bond with the first place they lived in together.

'And of course, as we're lovers, naturally we don't want to interact when dressed. It's a simple desire to feel each other's breath,' Rong Rong says. 'These kinds of experience are unique. Nowadays, people have lost primitiveness. Babies are born naked, but they cannot stay naked due to society's constrains. But we believe we have to return [to nature] from time to time.'

At the end of the day, it's realism - as well as love - that they want to express. This comes out in Caochangdi (2004-2011), a fisheye view of the growth of their family, and Three Shadows (2006-2008), a studio they sent up in Caochangdi in 2007. For them, the new architecture of the Three Shadows (designed by artist Ai Weiwei and named in honour of Lao Tzu's teaching) is also a new life.

'Our lives are changing and our ages are rising. And we have children, three of them. So photography is directly reflecting reality, and making changes to our lives,' Rong Rong says.

'These are evidence of the power of photography - to witness.'

Rong Rong's work, Blindspot Gallery, 24-26A, Aberdeen Street, Central, Tue-Sat, 11am-7pm; Rong Rong's collaborative work with inri, Blindspot Annex, 15/F Po Chai Industrial Building, 28 Wong Chuk Hang Road, Aberdeen, Thu-Sun, 11am-7pm. Inquiries: 2517 6238