[Stratoscope]

Thank you, you are absolutely right! I should have said "f-ratio" everywhere I used "aperture".

I'll leave my previous comment in its incorrect state in the hope that people will see yours to correct and clarify it. :-)

> The camera folks express aperture as an f-ratio, which is extremely confusing.

Isn't it the other way around? I think the mistake we self-proclaimed "knowledgeable" camera folks make is using the term "aperture" where we really should say f-ratio.

For example, I have two Olympus Micro Four Thirds lenses that are both f/1.8: a 45mm and a 75mm. Looking at these lenses it's pretty obvious that the f/1.8 is an f-ratio: the front element of the 75mm is much wider than the 45mm, as you'd expect.

So thanks to your comment, I will endeavor to use "f-ratio" where I've been misusing "aperture".