Post-shoot Image Processing
Capture NX-D's Astro Noise Reduction feature allows you to reduce unwanted bright spots in star images effectively with easy operation (for NEF only).
Astrophotography images captured with a long exposure time often display noise called bright spots that look similar to scattered stars. To reduce them, a workflow called "dark compensation" proves effective. This "dark frame subtraction (dark compensation)" uses a separate dark frame captured with a long-time exposure in order to decrease long-second noise.
If you want to skip capturing a dark frame and still want to reduce bright spots, the "Astro Noise Reduction" feature in Capture NX-D, Nikon's original RAW development software (available to download free from Nikon websites), allows you to do this easily and effectively (for NEF images only).