Re: [photo-3d] Hyper active

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

Another reason for "slight" hypers.  Resolution (or lack of it).

One of the many monoscopic depth cues, detail in texture, is diminished by
having less resolution than the eye normally resolves at a particular
viewing distance.

Relatively low resolution systems, such as stereoscopic video, can be
enhanced by a slight extension of the stereo base.  The results often look
more realistic than those obtained with a normal stereo base, because we can
see the little bumps and depressions in the subject stereoscopically, even
though they would not be perceived in a flat image or a stereoscopic image
with a "normal" stereo base at the same resolution.

How much wider?  Very little.  If it is noticeable as a hyper, it is too
much.  This is one of those subtle things you have to experiment with.  You
can not assign a number that will work the same with all equipment.  The
higher the resolution of your system, the less you need to (or should)
extend the base to achieve this.

With video, you can see it, and test it out, adjusting while you watch it.
One way I have found that works is to widen the stereo base until it looks
hyper, then narrow it a bit.  Sort of like focusing a camera by going past
the best focus, then backing up to the point that looked sharpest.

JR

----- Original Message -----
From: "Jim Harp" <matmail2@xxxxxxxxxxxxx>
To: <photo-3d@xxxxxxxxxxx>
Sent: Saturday, October 21, 2000 1:51 PM
Subject: [photo-3d] Hyper active


> > Hyperstereo, on the other hand, presents us with a view that would
> > be impossible to see in any way other than through photography -
>
> Although you're correct in theory that a hyper image can present a
> view that would be impossible to see with the unaided eye, I usually
> prefer scenic views that are slightly hyper (as long as there isn't a
> tree branch at four feet.)  In real life we don't stand perfectly
> still while looking at things.  As we move our heads we get more
> information about the depth in a scene.  This information is even
> more pronounced when looking at scenery from a moving car.  Hyper
> images convey some of this increased depth, and thus might actually
> be a more natural way of reproducing some scenic views. I suggest
> experimenting a lot if you're shooting hypers.  You can "bracket"
> separation just as you bracket exposure.  You might be surprised at
> how different a scene looks with differing separations.  My favorite
> way to shoot hypers is with two synched 35mm SLRs, especially when I
> can freeze moving traffic or flying birds.  With non moving subjects
> any camera can producing stunning results.  Jim Harp
>
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