Apparently we are now living in the age of Fifty Shades of Grey, where previously vanilla women, are now demanding to be tied to the bed and whipped. The plot, is about an unprepossessing woman who is ravished by an impossibly handsome billionaire who falls in love with her. All she has to do is to endure a regular thrashing by a man who is a love god in the bedroom.

Never one to go for the obvious, I began to wonder what happens at the moment of impact. These pictures, a taxonomy of blows, were taken with a sound activated switch and captures that precise instant.

Harold Edgerton was the inventor of high speed flash, which he used to capture things that were too fast for human vision, such as his famous bullet passing through an apple or a crown of milk caused my a single droplet. I had become fascinated by his work and acquired a sound activated switch and began experimenting, taking portraits of a friend with bursting balloons and exploding fruit and bottles, shot with an air rifle.

While in the midst of this, a friend phoned me and asked what I was up to these days. I told her and she commented on once seeing a video of a woman being flagellated in slow motion. In that instant the project, Four Hundred and One Blows, was born. I had first met her when she bought a print of The Most Scurrilous Washing Line in Christendom, an image of a nude woman standing in a kitchen with the family laundry hung out on washing lines attached to her pierced nipples. She hung it in her own kitchen. My friend had two degrees and three children and had a penchant for being whipped.

She came round with her partner and a sports bag full of different thrashing implements. In a darkened room the camera shutter is opened and when there is a noise the flash is activated. My switch had two dials, one to control its sound sensitivity and the other was a delay you tuned to achieve the moment of maximum impact. We went through the bag of canes, riding crops, tawses and cat-o-nine-tails and then I threw in my kitchen spatula and table tennis bat for good measure. When I showed the first photographs, some people, much to my annoyance, thought I was doing it with a sheet of glass or something.

I then decided to photograph different shaped arses and would ask women of my acquaintance and those I met at parties to aid me in my scientific endeavour. Surprisingly 50% said yes. It is a wonder I did not get slapped in the face –  but that would have made an interesting sound activated picture as well.