The image shows you a great deal of the Tokyo metropolitan area – you can see about 25km to the horizon, which adds up to about 500 sq km. I was lucky there was a big storm the night before, which cleaned the air, extending the visibility by many miles.

I spent months putting the whole thing together, but still haven't seen every detail in the image. But I've found a few nice highlights, including a guy sleeping on the ground after a rough night out, a Ferrari, a couple of guys practising baseball, and scores of little alleyways and streets where life is unfolding. I shot on a weekend so there are a lot of people simply doing their thing; there is a lot of life in the image.

I shoot almost exclusively 360º images. To me, it is the perfect kind of photography, capturing everything that exists from a single point in space. It is inherently geographic, in describing a single point on the earth, and in far greater detail than anyone could experience with the naked eye. I think it is amazing that I can extend the human senses in this way.

I shot the image using a standard DSLR camera, a Canon 7D, and a 400mm lens. The only special gear used was a robot camera mount connected to a laptop, onto which I bolted the camera and lens. This expensive piece of kit allows you to turn the camera by precise amounts using powerful stepper motors. On this shoot, the camera was moving, and simultaneously focusing and shooting frames, all without stopping, which lets you accomplish something that would otherwise take 10 times longer.

The entire image, taken from the Tokyo Tower, is made from three different sections which were shot pointing out from three different places around the tower. (These sections were joined together at the very end, on the computer.) Each section of images took 30-90 minutes to shoot, depending on the speed that the robot was turning the camera. So, I shot a whole set of images twice, on two different days.