Re: 3D quality in a lens?

[Paul Stenquist]

I agree completely. But selective focus and good bokeh are the 
attributes that have led to the "3D" descriptor being applied to lenses 
that are obviously not capable of 3D. I don't think anyone thinks those 
lenses produce actual 3D images. It's just another example of how 
language takes on other meanings over time. Of course it's not 
"technically accurate," but much of our language is not. Artists 
generally have no problem with that. Scientists do. That's the way of 
the world.
Paul

On Nov 12, 2004, at 8:42 AM, J. C. O'Connell wrote:
What you describe is a selective focus effect
but the out of focus background is still viewed
on same plane as forground, it would look totally
different with 3D photograhy, the forground
would not only be in selective focus, it would
be "popped out" in front of the background.
For those who have never seen 3D photography
or havent in seen it a long time, The thing
to remember is that with 3D photography, infinity
looks the same as 2D in 3D, objects that are
closer than infintity look "popped out" off the
infinity background. No 2D process does this with
any lenses no matter how good, so I simply do not
agree with saying any 2D lenses have a a "3D quality"
or effect. "Realistic Selective Focus" might me a better
term for the effect they are trying to describe.
JCO
-----Original Message-----
From: Paul Stenquist [mailto:[EMAIL PROTECTED]
Sent: Friday, November 12, 2004 8:15 AM
To: [EMAIL PROTECTED]
Subject: Re: 3D quality in a lens?
If you shoot a  foreground object with a long lens wide open, it
separates from the background in such a way as to produce an apparent
"3D" effect. Of course, as JCO points out, it's not really 3D. It's
merely the eye recognizing a difference between a sharp foreground and
an out-of-focus background. Lenses with nice bokeh, like the 77
limited, do this quite effectively. With extremely long lenses, like my
A-400/5.6, the effect is very easy to achieve. Here's an example:
http://www.photo.net/photodb/photo?photo_id=2875014
On Nov 11, 2004, at 10:33 PM, J. C. O'Connell wrote:
If you have ever done or seen any decent
3D photography you would know it's a really
dumb way to describe any 2D image. I wouldnt
read too much into it, or put too much trust
in the writers of just descriptions...
JCO
-----Original Message-----
From: Don Sanderson [mailto:[EMAIL PROTECTED]
Sent: Thursday, November 11, 2004 10:23 PM
To: PDML
Subject: 3D quality in a lens?
What is meant when a lens is described as having
a "great 3 dimensional quality"?
Or "it gives photos a 3 dimensional feel"?
I've heard this term used several times in describing
lenses, mostly WA's.
How does a lens lend a 3D quality to a photograph?
TIA
Don