On Sat, 15 Jun 2013 11:51:19 -0700, Savageduck
wrote:
: On 2013-06-15 09:25:16 -0700, said:
:
: I can find the Nikkor 14mm f2.8 but I'd REALLY like something with fair
: to excellent image quality (point spread OK) AND a low F# ... lower
: than 2.8. HELP!?? Vintage lenses OK.
:
: Why do you need a "fish-eye" faster than f/2.8?
:
: The Nikkor 14mm f/2.8 is not a "fish-eye" it is an ultra-wide angle
: lens. There is more to a "fish-eye" lens than just being a wide angle.
: Typically the idea is to capture a 180 degree field of view and that is
: usually attained by a combination specialized lens construction
: imparting a spherical distortion beyond that imparted by an ultra-wide
: angle.

I'm far from an expert in optics, but I was under the impression that it's the
other way around. I.e., an ultra-wide-angle rectilinear lens requires more
drastic corrections, because ultra-wide lenses naturally tend to be fisheyes.
Am I misinformed? (The Wikipedia article is vague on that point and can be
read either way.)

Bob