P3D Re: Re: A stupid (?) twin camera idea

[Alan Lewis <dlewis@xxxxxxxxxxxx>]

> One partial work-around is to "overlap" the bodies, kind of like this:
> 
>       +--+
>       |  |
>      +--+  +--+
>      |        |+--+
>      +--------+|  |
>           +--+  +--+
>           |        |
>           +--------+
> 
> The problem here, of course, is that one lens is now further back than
> the other.  So, here's my stupid idea ... is it possible to put
> different focal length lenses on the cameras to give them,
> effectively, the same field of view? 


Your concept for camera placement comes just a little sooner than I can
get my next twin rig "weekend project" on my web page.  It will be
titled "A stereo digital camera for under $200!?".

I have twinned Kodak DC20 digital cameras using your layout.  This puts
the cameras about 1" different in distance from the subject.  Since the
results are instant I have tested this concept quickly (at least within
the spec's of these cameras).

This layout works fine for images viewed as conventional photo's,
meaning at half arms length or so.  I haven't tried viewing prints under
magnification.

I cannot notice any problem with differing magnifications.  My test
shots were from about 6 feet, and one from 18", and some from greater
distances.  The shot at 18" was still easily viewable on the computer
screen by using the Freeviewer's Assistant (or one could cross eye
view).

One thought that I had along the way in this project; that using the
Freeviewer's Assistant would partially correct for the differing
magnifications.  This viewer lengthens the right eye distance from view
by about 3/4".  So if the cameras were offset in the proper manner to
match this longer right eye viewing distance......

I don't know if it actually corrects for the differing magnifications,
but I can easily view a print pair using the viewer.  But I also can
easily cross eye freeview the pair too.

So my opinion on the matter for you is to just do it (using the same
focal length lenses).  Don't worry about theory getting in the way of
reality.  When in doubt, the only way to research and resolve an issue
is to actually try it.  You'll know soon enough if it works!
-- 
_______________________________________________________________
Alan Lewis
mailto:dlewis@xxxxxxxxxxxxx
Home of the stereo wedding package, and weekend stereo projects
http://www.arlington.net/homes/dlewis


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