In some ways this is a ridiculously lucky picture – it is rare to have this sort of access to polar bears in the wild. Furthermore, the positioning of the second polar bear is almost perfect and that was totally outside of my control.

But I do believe that in fact this image endorses an approach which leans heavily on desk research, discomfort in the field and the preference for proximity, immersion and wide angle lenses. The 35mm lens is my favourite lens and if I was to carry one picture in my wallet to explain why, it would be this picture. The 35mm is such a crisp and examining conduit.

At the time, I could not see what was in the viewfinder as I was holding the lens 30 inches below my eyes in order to get the right ground up perspective. All I remember is my heart pounding with a mixture of fear and adrenaline – which in retrospect is hardly surprising.

My sense is that this picture will stand the test of time.