I often get asked how I determine what the correct exposure is for any given photograph. The answer of this particular question is about as easy to answer as “how long is a piece of string”. The technical answer might be to use an incident light meter reading, or a grey card or use your camera meter to get a reflective light reading. But all these particular answers miss the vital point. The answer is probably best answered with a question (or two). “What mood do you want to create?” or “What story are you trying to tell?”. Take these two examples:
Both these pictures where taken at the same time, using two different exposures. Neither is the wrong exposure, but both have a very different mood to them. You could be forgiven for thinking that the second image was taken during twilight, when in fact it was taken on a bright(ish) day at approx 2pm. The top image was exposed for the building, while the second was exposed more for the sky, and because the side of the building captured was in shadow, it looks dark (underexposed). If I was trying to show off the detail of the building, then the first would be considered the best of the two images, for two reasons. The exposure shows the buildings detail better than the second, and the way the image is framed tells the viewer that the building is the centre of attention and because of the low camera angle it is telling the viewer that it is a grand building. If I was trying to communicate a sense of mood to this grand building then the second image would be considered the best of the two as it is much more dramatic than the first. Exposure can make a bright day seem dull and a dull day seem bright, it can make a photograph in the middle of the day look like it has been taken at sunset depending on how you expose it. So if you ask me “What is the correct exposure?” I will answer “As long as a piece of string”.