We climbed Scafell Pike yesterday and stood on the highest ground in England. Sellafield was prominent in the view - a big employer of physicists in these parts. Here are two photographs taken from the same place. My current camera is a cheap but functional one. It has digital zoom. Essentially, that magnifies the middle of the image on the CCD detector. It makes each pixel bigger but that tends to blur the image as you can see. My last camera had optical zoom. Optical zoom involves moving a concave lens backwards and forwards between two convex lenses. It affects the amount by which the light is bent and you can make the same light cover more pixels. The image is bigger but not blurred. Trouble is that I got sand into the gear wheels that moved the concave lens. My new camera may be cheaper but is more robust!
