There's an option (D300) to turn on NR for long exposures and high ISO settings. The latter has options for high, normal, or low. I only shoot RAW, and I import my images into Lightroom for processing, where they also have NR correction. Does NR apply to RAW files in the camera? If so, is it a good idea to do it there and/or later in software? Does it come down to composition choices? Should high, normal, or low be used? Stupid questions, but it's time I get these things straight.