Focal Length vs. Focal Ratio: What They Do Conceptually!

Correction!
Magnification is calculated by Telescope Focal Length/Eyepiece Focal Length rather than Eyepiece Diameter!

I decided to make this conceptual video about focal length and focal ratio after a new PhET simulation on Optics was released by Colorado Physics.
Visualizing these concepts is especially helpful if you are just starting out.

PhET provides fun, free, interactive, research-based science and mathematics simulations developed by University of Colorado.

Although their new optics simulation was not designed specifically for astronomy or astrophotography, it can be used to visualize what focal length and focal ratio what you see and capture.

Links:
https://phet.colorado.edu/en/simulati...