> If you search for lenses for "real" cameras with those apertures and focal lengths, you'll find 4 digit price tags for each one.
The aperture is relative to the diameter of the first lens element. So you can’t just compare these values directly.
The aperture is relative to the diameter of the first lens element. So you can’t just compare these values directly.
The catch is: a phone has a much smaller sensor, so at the same f-stop, across the whole sensor less light is gathered and consequently, you have a weaker signal.
f-stop doesn't mean much other than the maximum that the aperture for that lens can open.
It doesn't indicate lens or element quality, or aberrations. There's a reason that pixel peeping, gear games, and reviewers are so prevalent in high end photography.
As a simple extension to this, most of my lenses work better a few stops before maximum f-stop.
So, yes, but no.
For the rest - yeah, f# is just one of important specifications.
The aspects you are now referring to are about the lens quality. Yes, I would expect a real camera lens to be much better than the lens of an iPhone. There is no doubt about that. But in the posting I answered to, you spoke about the comparability of aperture values.