Astrophotography describes the imaging of astronomical objects along with large areas of the night sky. According to Wikipedia, the first photograph of an astronomical object (the Moon) was taken in 1840, although it was not until the late 19th century that advances in technology allowed for detailed stellar photography.
In addition to recording the details of objects such as the Moon, Sun, and planets, astrophotography is also capable of imaging objects invisible to the human eye such as dim stars, nebulae and galaxies. This accomplished by long time exposure, as both film and digital cameras can accumulate and sum light photons over extended periods of time.
As HackADay’s John Marsh notes, the basic idea is to capture images otherwise undetectable by the human eye through longer exposures.
“Unfortunately, the big ball of rock we all inhabit has a tendency to rotate, which means you need to move the camera to keep the night sky framed up,” he explains.
Unsurprisingly, the vast majority of professional astrophotography trackers require precision parts and fabrication. However, a Maker by the name of ZigZagJoe found an alternative with Chris L. Peterson’s stalwart Cloudbait Observatory model. Dubbed the “Barn Door Tracker,” the platform is powered by Atmel’s ATtiny85 microcontroller (MCU) and runs a pre-configured table that determines step rate against time.