Patrick Bell Posted March 1, 2021 Share Posted March 1, 2021 Hi I just ran through the on-shot colour astrophotography tutorial. Is there a tutorial or guide as to what the requisite sets are. Dark frame for instance I guess are taken with the lens cap on? But what are all the others? Quote Link to comment Share on other sites More sharing options...
kirkt Posted March 1, 2021 Share Posted March 1, 2021 @Patrick Bell See: https://practicalastrophotography.com/a-brief-guide-to-calibration-frames/ for example. Collecting a set of these frames is called "calibration" - characterizing your camera's sensor and optical systems. Calibration helps deal with the issue inherent in astrophotography, which is mostly about increasing signal-to-noise ratio (SNR). The sources of light that you are trying to capture are so far away that very little of their light falls onto your camera's sensor, so it is a balancing act between exposure time (light gathering) and SNR. As exposure time increases, not only does your subject move across the frame, but the electronics in your camera heat up and create noise, above and beyond the noise inherent in the system. Dark frames handle the noise inherent in the system, and bias frames deal with the noise created for a specific exposure time and temperature. Flat frames help deal with the optics of the system (color and vignette issues inherent in the optics). You want to capture the noise-related images at the same temperature as the Lights, although it may not be super critical for what you are trying to do. And, of course, Light frames are the actual images of the subject. You can also use these techniques in critical non-astrophotography settings, where you need a clean signal but lighting does not give you a lot of signal to work with. Have fun! kirk Quote Link to comment Share on other sites More sharing options...
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