One question that I get a lot is "what does ISO mean?" and I have to be honest, I have no idea what it stands for. I do know that it measures your "film's" sensitivity to light. Although I'm sure no one is using film, it works the same way with digital. Most point and shoot digital cameras have 5 or 6 different options, 65, 100, 200, 400, 800. Each number tells you how sensitive your sensor is going to be to the light hitting it. 65 is not very sensitive so it can be used in bright situations. 800 is very sensitive, best used in low light situations. At the same time the larger the number, the lower the quality of the image. Images shot at 800 will be more "grainy" than images shot at 65. Images shot at 65 will be more crisp and allow more adjustments in post production. The hay bales image was shot at 400 ISO, these were film days so I couldn't change it. I enlarged it slightly and made minor adjustments and the sky became really grainy. During the film days we called it "grain." In the digital world we refer to it as "noise. The Westminster building image was shot at 50 ISO and with the increased quality I was able to make several adjustments without damaging the file.
