ABSTRACT
Many astrophotographers sensibly start with their current digital camera and later on, when they wish to progress, contemplate a dedicated model. Astrophotography is far more demanding and any evaluation cannot avoid becoming technical since it involves an understanding of the inner-workings of the silicon, to correctly interpret published specifications or amateur “reviews.” It makes sense to explain and contrast the different specifications that fall into the following general categories: sensor architecture, noise performance, and scale. In the 2010’s the overwhelming majority of astro cameras used 10-year-old CCD-based sensors that outperformed contemporary CMOS designs. At the same time, CCD sensors were to be found in professional observatories and space telescopes. Some new CCDs have been developed, typically in smaller sizes, for specialist applications such as low-light surveillance and some video applications. CCD and CMOS sensors use different architectures; while both designs convert incident photons into an electrical charge, the way that each photosite charge is read and converted is quite different.
