darksubtracted

Dark subtraction is a technique used in astronomical imaging to remove the background light from an image, revealing the faint details of celestial objects. This process is particularly important in astrophotography, where the brightness of the night sky can obscure the light from distant stars and galaxies. Dark subtraction involves capturing a series of images of a blank area of the sky, known as dark frames, and then subtracting these images from the light frames, which are the images of the celestial objects. The dark frames are taken under the same conditions as the light frames, including exposure time and camera settings, but without any light entering the telescope. This ensures that the dark frames capture only the electronic noise and thermal noise from the camera sensor. By subtracting the dark frames from the light frames, the astronomer can remove the noise and background light, resulting in a cleaner and more detailed image of the celestial objects. Dark subtraction is a crucial step in the processing of astronomical images, as it allows for the detection of faint objects that would otherwise be obscured by the background light.