P3D Re: Focus and Depth Together

[Eric Goldstein <egoldste@xxxxxx>]

Andrea Blair asks:

> Can an image be sharp (in respect of DOF) and still be *flat*? Does DOF
> automatically produce the perception of depth in stereo? If so, is an
> extremely sharp but completely flat stereo image better/worse/different
> than a selective focus image that shows depth? If you (anyone) had to
> choose, what would be your preference? Any thoughts?


Andrea asks some interesting questions, trying to help us get our arms
around the relationship between focus and the perception of depth if one
exists. I'll take a stab and give my thoughts, but anyone who really
knows what they are talking about should jump in...

First, I'd just point out that flat pix are only flat in relation to a
stereo pair. They contain all the depth cues which stereo pairs contain,
save one: parallax. One eyed people perceive depth, and "one eyed
pictures" normally have plenty of depth information within them. Some of
the most beautiful and revered flat photographs (and paintings) are
noted for their remarkable ability to convey roundness, depth,
dimension, etc. These are no more illusional nor are they less "real"
than the reconstruction of depth via parallax. Some of us stereophiles
(stereosexuals?) may regard the reconstruction of depth via parallax as
a more striking with greater impact but that is purely subjective...

Terminology becomes important here... how flat is flat and for that
matter, how sharp is sharp as this is not a discrete characteristic but
a matter of degree. I'd say an image can be sharp and flat... imagery
placed at infinity in sharp focus which represent the furthest element
in a scene would be an example. But one must qualify this with the
notion that even at infinity depth cues often exist... distant mountains
seldom if ever look "flat," though they may not contain any resolvable
parallax information. The nighttime sky often (but not always) looks
flat, but daytime clouded skies usually have some dimension to my eye,
though stereographers will often regard clouds shot at normal lens
spacing as flat. Again, purely subjective.

You ask if an extremely sharp but completely flat stereo image
better/worse/different than a selective focus image that shows depth and
my answer is that is it irrelevant to me! I am a creative director by
trade and so commission all manner of still, film, video, etc, and am
oriented toward whether an image is successful or unsuccessful rather
than good or bad. A successful image communicates what was intended from
both a content and an emotional POV in a particular context. An image in
one medium and application may be entirely successful and in a different
application be a flop! You are shooting for competition? For commercial
application? For a client? For yourself? What are your hoping to achieve
with the image and within what context? It is only within this framework
that I think a creative piece can be successfully judged...

My own personal taste is toward images which offer impact, compelling
visual explorations, which are provacative and emotional. Often the
greatest surprise for me as a creative director, teacher and judge is
when someone presents a piece which provides an extraordinary view of an
ordinary subject and so provides a delightful visual
surprise/exploration. I also have an intense respect for those who can
light well and use light to help achieve these ends. Also for those who
are masters of composition and who really understand how a visual
hierarchy works. The medium (flat, stereo, b/w, color, moving, still,
MOS, whatever) is largely irrelevent to me...

BTW, I am grateful to George, Andrea and others who are leading by
example and setting a moderate and rational tone for the discussions on
this list. While I understand that there are those who feel passionately
about there opinions, the presentation of our thoughts in a context
which encourages discourse and invites discussion is to be admired and
emulated. We are, after all, all colleagues in our pursuite of improved
skills and teachers to each other in this endeavor, and I greatly
appreciate the patience and respect shown by listmembers to by screwball
ideas though they may not agree with them, and encourage each of us to
return that patience and respect in kind...


Eric G.


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