Noise is the digital equivalent of grain in film. It’s random electrical signals captured by the photosites on the camera sensor, and usually this background noise level is so low compared to the brightness of the captured picture itself that you just don’t notice it.
This setting increases the camera sensor’s sensitivity to light. Each ISO step doubles the sensitivity, so it’s easy to use ISO as another exposure control alongside shutter speed and lens aperture. The more you increase the ISO, though, the more the image quality degrades.
If you never thought you’d need to pay attention to the Lightroom noise reduction settings, you might need to think again. Like a lot of photographers I shoot RAW files on the assumption I’m going to get better image quality by processing the images myself rather than leaving it to the in-camera JPEG processing. That’s fine […]