In my life, I have been fortunate to visit many of the great sports stadiums of the world – mainly as an accredited cameraman, but also as a spectator. These venues – when they are full – become tribal theatres that personify the location in which they nest – Boca Juniors ground in Buenos Aires for instance, or Celtic Park in Glasgow and most certainly the Nou Camp in Barcelona. Outside football, the same is true of the MCG in Melbourne and indeed the Green Bay Packers formidable home in Wisconsin. They are all proud regional fortresses that embody the soul of their local culture. The simple expression “playing at home” can underestimate its multi-dimensional connotations. It is a turn of phrase that has to be digested both literally and metaphorically.

In sports stadiums, the replacement of the old terraces may have served to improve the comfort and general level of facilities, but it has also rendered many of the big new stadiums generic – big two tier structures able to accommodate 70,000 or 80,000 spectators are now sprinkled across Europe. Some – such as the Allianz Stadium in Munich – are magnificent in their aesthetic boldness, but in the main, the architecture is formulaic rather than unique. In London, for instance, there is not a huge gulf between Twickenham, Wembley, the Emirates and the Olympic Stadium. All are individual and structures of pride of course to their loyal supporters, but somewhat homogenous to neutral observers.

In my view, there is one stadium that stands out as unequivocally unique in its structure and also houses a crowd that remains tribal, seemingly timeless and raw. It is the Westfalenstadion – the home of the famous football club Borussia Dortmund in the Ruhr valley of Germany. This is an artisan’s club with longevity, heritage and deep roots in the community – it prides itself on being more inclusive and less grand than its aristocratic and exclusive rivals Bayern Munich – the wealthy powerhouse of regal Bavaria.

Dortmund is the epicentre of the Ruhr – the largest urban agglomeration in Germany with a population of over 5.1 million and the football club is part of a 120,000 strong membership based sports club. Founded over 100 years ago, the publicly owned Borussia Dortmund boasts the highest average attendance of any football club in the world.

The vast South Stand at Dortmund’s stadium (the Sudtribune) is still largely terraced and consequently holds more spectators than any goal facing stand in the world. This is an empirical fact. There are decent single structure goal stands in the UK – the Kop at Anfield and the Holt End at Aston Villa, but Dortmund’s south stand not only holds 24,500 people (double that of the Holt End) but it does so in one single tier – there are no separate levels physically splitting this great swarm of highly impassioned spectators or empty corporate boxes.

Of course, Dortmund – at home – play in their famous yellow and black and in Germany the Sudtribune is known as “the yellow wall”. It is almost always full some 30 minutes before kick off – no matter the opposition. Ticket holders in the stand are free to drink and smoke and that they certainly do. It is indeed a wall of yellow, but also a wall of noise, regional pride and adrenaline. It is as if someone has bottled the essence of Northern Germany and then sprayed it onto some concrete steps.

I wanted to capture an image that did this extraordinary setting justice. It is not easy. For one, there is mesh netting in front of the stand and secondly, in night games or even day games in the winter, there is too little light at the back of the stand – as, irrespective of the steep incline, it moves away from the field and any source of light. Furthermore, there is no point trying to take a picture with a field pass as only the first few rows will be at the same level as the camera. The picture will be running away from the eye as indeed will the focal point. That is probably why the wall has never been captured that well by a press cameraman.

So the best solution is to go unofficially and work from a seat in the adjacent main stand at a mid-height level. This however creates a further problem in that professional looking cameras are generally not allowed within the ticketed stadium – as is the case with most sporting arenas. This is – of course – to protect against unlicensed strong imagery of the players, not the crowd.

Two days before a big Sunday afternoon game against their local rivals – Bayer Leverkusen, I sat in my beach house thinking about a way around this riddle and eventually, in a moment of unusual clarity, I found the answer.

FirstIy, I really only needed a structurally small standard lens – not a telephoto and most security personnel are looking for a big lens, not a small one – after all phones are now decent cameras and phones are not confiscated. I also did not need a fast motor drive back – just a high resolution camera body and Nikon now have the best – the D810. It is small and can fit into a deep pocket. Meanwhile my warrior lens – the 58mm, can be put in a back trouser pocket and look like the back end of an amateur’s camera – not the best optical lens in the business. So I decided I would decouple the camera and lens and go into the stadium wearing a deep pocketed winter jacket. Ostensibly I would be carrying no camera at all, just a phone and a new Dortmund jacket for my son back home who loves the club.

On my arrival, I scalped a ticket in the exact section of the ground that I needed to be in and passed through security with no issues. Two factors seemed immediately in my favour -firstly Dortmund were top of the league and the crowd were – even by Dortmund standards – fully engaged. An early goal from Dortmund would clearly be wildly celebrated. The weather was also good and with a 4.30 kick off in the early autumn, I anticipated kind light for at least the first 30 minutes.

Throughout those minutes I was focused not on the match, but just on the Sudtribune. I needed a home goal before the light dropped and in the 19th minute I got my wish. I believe that there are over 10,000 people in this image – all celebrating as one. It is unity on a scale that has perhaps never been captured before – certainly not with this clarity.