I read from foam to fo'c'sle.

The formula for the f-number is actually very simple, but you'll probably never have to use it.

f-number = focal length / diameter of the aperture

I also can never remember how the focal length is measure on a lens, but the shorter ones are wide angle lenses and the longer ones are telephoto lenses. 

https://en.wikipedia.org/wiki/F-number

https://en.wikipedia.org/wiki/Focal_length

The word of the episode is "focaccia".

https://en.wikipedia.org/wiki/Focaccia ...