This paper details the calculations for one of the largest FOV systems in modern astronomy. Section 3 explains the relationship between focal length, pixel size, and the resulting angular resolution (arcseconds per pixel), which is the foundation of any FOV calculator. The Fundamental FOV Formula
Here is a solid guide to understanding and calculating Astro FOV, referencing the tools and standards that were solidified in 2021 and remain the industry standard today. astro fov calculator 2021
This was the browser-based workhorse. Its "Imaging Mode" allowed you to select from a dropdown of 100+ telescopes and 50+ cameras. The 2021 update added "Object Lists"—you could load the Messier catalog and cycle through targets to see how each framed up. Feature: Dynamic FOV Simulator with Equipment Library This