Astrofotografiaan

Astrofotografiaan is the practice of capturing images of astronomical objects and phenomena through photography. It encompasses the Moon, planets, stars, star clusters, nebulae, galaxies, and transient events, often revealing details not visible to the naked eye. The field blends observational astronomy with digital imaging and image processing to document and study the cosmos.

Imaging in astronomy relies on long exposures and precise tracking to counteract the Earth's rotation. Photographers may work with wide-field setups using camera lenses, or with telescopes for deep-sky objects. Planetary imaging often requires high frame rates and stacking of many video frames. Narrowband imaging using filters such as H-alpha, OIII, and SII is common for emission nebulae, while luminance, color, and luminance-weighted combinations expand dynamic range.

Equipment commonly includes a stable mount with accurate tracking (often a motorized equatorial or alt-azimuth system with an autoguider), a telescope or telephoto lens, and a detector such as a CCD or CMOS camera. Imaging can be performed with DSLR or mirrorless cameras as well. Accessories include guiding cameras, focal reducers, filter wheels, and light pollution or color filters. Calibration frames—darks, flats, and biases—are routinely captured to remove sensor noise and optical artifacts.

Processing plays a central role. Stacking multiple exposures improves signal-to-noise ratio, followed by alignment, calibration, and stretching to reveal faint details. Software tools manage image calibration, registration, stacking, and post-processing, including color balancing and noise reduction.

Planning considerations include site selection, sky conditions, object visibility, lunar phase, and local light pollution. Solar imaging requires specialized filters and safety precautions. The community includes amateur and professional practitioners sharing data and techniques to advance imaging capabilities.