On Sun, 15 Jul 2001 18:44:12 GMT, paminof@nospam.org (paminof) wrote:

>I've always been intrigued by the question of what focal length
>approximates the field of view of the human eye.
>
>In 35mm terms, everybody says 50mm, but I've always thought it's more
>like 65-75mm. Then again the human eye is designed for binocular
>vision, the brain processes the image in ways that no camera can
>approximate, and perception is hard to quantify simply in terms of
>millimeters . . . but it's somewhere between Zen and a neuron synapse.
>:-)
>
>Leonardo Da Vinci drawings, for example, have a field of view that is
>different than the famous 18th century paintings of Napoleonic battle
>scenes. How different artists perceived scenes (in space) before the
>advent of photography is an interesting comparison . . .

Ah, this has interested me, too...
But, my conclusions are different - see article I wrote on
this, at: www.David-Ruether-Photography.com/articles.html#perspective
The short of it: there is no FL that approximates the field
of view of the human eye except maybe the 6mm Nikkor lens
for 35mm, cropped vertically to approximate the cutoff of
the eyebrow and cheek structures... Interestingly, we do
see in spherical perspective, and VERY wide angle, yet most
people are hard to convince - but on the other side, most
people attend to only a tiny part of their vision acceptance
angle, so one could say that a 5000mm+ FL approximates the
angle of vision for many...;-) In photography, it has been
traditional to call a lens FL about equal to the diagonal
of the film "normal" - but this is just convention, with no
basis in what we see other than that the divergence between
the "look" of rectangular and spherical perspectives is not
very great within this convention. For me, I can see clearly
(and attend easily) an angle of view about the same as my
glasses show - but this angle is about the same as that
covered by my 12mm Voightlander rectangular-perspective
35mm-format lens (and the perspective is VERY different
from what I see - though similar to what the spherical
(fisheye) perspective viewfinder for the 12mm shows...;-)
I can also just about attend to items 90+ degrees
horizontal away from straight ahead view, something that
is impossible in rectangular ("normal") perspective
(though it would be possible in cylindrical perspective).
Anyway, this is a very interesting subject area, and it
is interesting to see old WA paintings of column rows with
arches that "fudge" somewhat into spherical perspective
'cuz strict "normal" perspective fails in WA views - and
the Greeks knew 'bout all this, and added fisheye
"distortion" ("entasis", as I recall...) to building lines
to make their buildings look bigger by exaggerating the
fisheye perspective effects of closer viewing...;-)