Imagine you're a wildlife photographer. You're stalking a rare, brightly plumaged bird through the undergrowth. You lie in the grass for hours, centipedes and large spiders crawling over your face and neck. Then, when your body is stiff and aching, sun baked and drenched in sweat, the bird alights on a log with a fish in its mouth, the sun glimmering delightfully from the scales. You squeeze the shutter and success is yours.