The next assignment was to photograph a cyclist who was going to take part in the Welsh Tryptk and raise money for the Derbyshire Association For The Blind. The distance was only as far as the Court House, but to have walked would have meant crossing over a dual carriageway. Steve had spoken to the chap before we left the office to ask him to come prepared looking as though he was just about to depart. He managed to bring his bicycle, but no helmet or rucksack etc! It was here that F-numbers were explained to me. It's not the first time by any means, but perhaps the first time that it registered exactly why you would want to dictate your depth of focus. If you widen your aperture to a low number, taking care to check that your film speed doesn't fall below, say 100, then the background will be out of focus (smaller depth of focus), thus highlighting your subject by being in focus! (It's only taken me 30 years to get the hang of F-numbers)