P3D Re: the value of toe-in

[Dylan The Hippy Wabbit <spacey@xxxxxxxxxxxxx>]

Hi,

Boris Starosta wrote:

>The response to my Contest has been appalling!  Not even Dave Spacey has
>submitted an entry, and it was his question to me regarding the setting
>of a stereo window with my twin rig, that gave me the impetus for the
>contest to begin with.  Come on now!

Well I did try.  I downloaded most of the images, though not the nudes.
My employer has good reason to get huffy over that.

My method was to zoom in close, and use the status bar of my fave graphics
editor to read the pixel positions directly.  I figured that keystoning
would show up most where a foreground object approached the four corners.

I was on a hiding to nothing there.  Most of the subjects don't go near
the corners.  And the hoopy diagonal compositions in many of the
architectural shots put the geometry beyond my imagination's ability to
figure it out.  I'd about satisfied myself that the sculpture and food
shots were toed in, and just assumed that the computer generated efforts
wouldn't need to be.  But my eyes were sore, and I ran out of time.


> I could not ignore Dave Spacey's question of several days ago because it
> was so perceptive. 

Aw shucks, I'm touched.  At least, that's what I'm often told.  ;-)


> But why conceal my use of the technique until now?  Because it is "not
> recommended," and I wanted to spare myself the inevitable criticism.

The fact that no one noticed, except maybe in hindsight, suggests that
*very* subtle keystoning isn't too bad a problem.  Just on logical grounds
there has to be a threshold below which it is imperceptable.

One 'advice for beginners' website I read recommends no more than 3
degrees of toe in.  Largely getting away with > 5 is encouraging.

>But the fact is, if I shoot close up subjects with a vertical twin
>rig, I HAVE to use convergence in the cameras to get a full frame 35mm
>slide pair.  

Just another of the compromises that make 3D a good challenge.

>And the winner is...
>BILL STICKLEY!

Congrats Bill.

And thanks for the interesting challenge Boris, even though I never
completed it.

Dave Spacey



______________________________________________________________________________

Walk tall, walk straight,
Spit the world right in the eye.

-Kevin Godley and Lol Creme


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