Guides
How astrophotography equipment works and how to set it up, explained with diagrams. Each guide lists the sources behind its figures.
Camera specifications explained: what the numbers on an astronomy camera mean
What sensor format, pixel size, full well, read noise, QE, ADC, shutter, image buffer and back focus mean on an astronomy camera, and when each matters.
Sensor sizes explained: why a 1-inch sensor isn’t an inch
What 1-inch, 4/3, APS-C and full frame really mean: where each name came from, from 1890s film to TV camera tubes, and the true size of each sensor.
How to measure your dew shield
How to measure your telescope's dew shield outside diameter for a made-to-measure Bahtinov mask or star spike generator.