A galaxy is faint and the Earth is turning, so a long exposure on a fixed camera produces star trails and little else. The fix is a tracking mount that rotates against the Earth's motion, holding the target still on the sensor. From there it's repetition: many exposures of the same patch, often several minutes each, taken across a night or across months. Software aligns and averages them. That strengthens the real signal and cancels the random noise, and the faint spiral structure emerges from what looked like empty dark. Colour depends on the equipment. One-shot colour cameras and DSLRs record colour information through a sensor filter array; monochrome cameras record separate filtered channels. Celestron’s imaging explanation covers DSLR and colour deep-sky work. Calibration and processing still affect the final picture; not every camera produces a grayscale image.
Then comes processing: stretching the brightness curve so the faint outer arms become visible without blowing out the core. This is why serious astrophotography is measured in total integration hours rather than shutter speed. Our galaxy collection includes AI illustrations and Webb imagery on Pillars of Carina; product pages identify the process and source credits. If you already have your own shot of the sky, you can print it on canvas and we'll check the resolution against every size before you pay.
This answer belongs to Looking up. Its neighbours are are photos of nebulae real, which deals with the colour rather than the exposure, and the Pale Blue Dot, a photograph taken from beyond the orbit of Neptune.
Written by Craig Fearn, Aphelion Prints. Last updated .