"I wanted to capture something more special and more personal, so I only brought an analogue camera. I wanted to focus on my wife and I wanted the pictures to be valuable. When I came back to Hong Kong I had the negatives. It's a physical record instead of just some data," says Tso, GM of Lomography Asia Pacific, the organisation that promotes analogue photography in this digital age.
Tso has his dream job. Born and raised in Hong Kong, he studied design and photography at Concordia University in Montreal, Canada. It was a time when digital photography was just becoming widely available, but he was more concerned with fine art and loved the magic of developing his prints in the darkroom.
One of his classmates had a small, compact Russian-made camera: the Lomo LC-A. Since 1984, it had been made at the Lomo factory in St Petersburg and the point-and-shoot camera would have gone out of production if not for three Austrian students who chanced upon it in a flea market, loved it and persuaded the factory to keep making the model.
The students called themselves Lomographers and established The Lomography Society in Vienna in 1992.
Tso didn't see the LC-A camera again for several years. After graduating, he worked as a designer in Montreal then came back to Hong Kong in 2008 looking for work. The world's first Lomography shop had opened in Sheung Wan, one of the first galleries to open in the now trendy neighbourhood. He got a job as a designer, working in the office above the small shop, and on his first day of work his boss presented him with an LC-A and suggested he experiment with it.
It was the beginning of a love affair with Lomography. Tso now takes his LC-A with him everywhere, but limits himself to just one roll of film - or 36 shots - a month. Taking just one picture a day makes him slow down to consider the shot and whether the scene is worth photographing.
"With an iPhone, you can easily take 1,000 or 2,000 photos a day, but we only have so much time and can only process so much data," says Tso.
If smartphone snapshots are the McDonald's of photography, then Lomography is the slow food movement: it's about slowing things down, of enjoying the process. The cameras use traditional film and the simple lens produces retro-looking photographs.
It's the imperfections - the colour saturated or the image slightly blurry - and happy accidents that appeal to fans.
"It's like people who collect vinyl records. They don't do it because the sound quality is better, it's about the whole physicality of the medium - they can hold the record, 60 minutes of music, they have to play it on a record player and change sides," says Tso.
His return to film reminded him of his youth and the hours in the dark room messing about with chemicals and conjuring up images. But for many of the new converts to Lomography, the retro-style feel is new to them and Tso says that's where the attraction lies.
"Photography has evolved so fast over the past 10 or 20 years. Now most people don't even use a digital camera, they just use a smartphone, it's all too easy. But with a film camera, you have to load the film, shoot, take the film to the lab and only after a week do you see the photos."
Today Tso oversees a team of 20 staff in Hong Kong and is responsible for Lomography operations in Asia. With stores in Singapore, Tokyo, Bangkok, Beijing, Guangzhou, Jakarta, Seoul, Taichung and Taipei that's a lot of ground to cover.
"The way I see it, the more analogue the product, the more technically advanced you have to be," he says, explaining that these old-style cameras were initially sold only online.
The website is the focal point for the Lomography community and fans can share photos, swap tips - and make friends. Whether he's travelling for work or pleasure Tso usually looks up Lomography friends he has met on the site. And with three million visitors to date, the site is growing fast.
The three students who first stumbled across the LC-A are still at the core of the business, which is why the company is headquartered in Vienna, but Hong Kong is a significant centre for the movement. Not only is it home to the first physical shop and the centre for Asian operations, it's also the birthplace of two of the bestselling Lomography cameras.
The Diana F+ is a reincarnation of the all-plastic, medium-format camera that was originally produced by the Great Wall Company in Hong Kong in the 1960s. The square-format pictures with a dreamy soft-focus have earned it a cult following. And the Holga was originally made in Hong Kong in 1982, but production was stopped because of problems with light leakage and precision - the same reasons why Lomography fans love it today.
Reintroducing outdated cameras will continue to be the mainstay of Lomography's business, but what's really exciting Tso right now is the reinvention of the legendary Petzval lens, which was first conceived in Vienna in 1840. Lomography launched a Kickstarter campaign last year and 3,000 people committed to buying the new release of the classic lens. Once those orders have been honoured, Tso expects it to be available for sale in the store from July.
"Reproducing lenses with an interesting historical background is going to be a new focus for us. It will especially appeal to people who are interested in fine art," says Tso.
This month, Lomography celebrates the 30th anniversary of the camera that started it all: the LC-A. The Hong Kong store is planning a big community event on June 13; keep an eye on the website for details nearer the time - www.lomography.hk