photo-flash delay

One of the more specialised areas of photography is the use of ultra-short exposure times to capture events occuring at high speed. Everyone will have seen the results of this technique at one time or another: a light bulb in the process of disintegrating under the impact of a hammer, or, as in the picture shown here, a splash of water. Photographs of this type can be taken fairly simply by employing an `open-lens` approach, i.e. the photo is taken in a darkened room and the lens of the camera is opened before the subject is illuminated. The lighting is provided by a high-speed (electronic) flash unit capable of providing extremely short exposure times.