Re: [photo-3d] Re: Depth ranges

[Brian Reynolds <reynolds@xxxxxxxxx>]

Paul Talbot wrote:
> abram.klooswyk@xxxxxx wrote:
> > However, John Bercovitz presumes that viewer focal length is equal
> > to "working" camera focal length.
> 

Given the number of fixed lens (i.e., non-interchangeable) stereo
cameras, and his position as "Ortho Man" this isn't a bad assumption
(and it is pointed out in the paper).

> He does indeed and while I have pointed that out at other times, I
> erred badly when I neglected to do so in this case.  Thanks for the
> reminder.
> 
> > So be prepared to buy a set of different stereoscopes and sort
> > your slides according to focal length.
> 
> I wish I fully understood how to modify application of the formula
> for when the viewing FL does not match the taking camera's FL.
> Although I don't do stereo base calculations this way for my
> shooting, it would be nice to have a version of the spreadsheet that
> took both the shooting and viewing FL values into account.  (Is Tom
> listening?)
> 

In tech-3d Michael K. Davis has posted an extension of John
Bercovitz's work that includes a factor for mismatched viewer
vs. taking lens focal lengths.  He first posted this last year and has
discussed it again recently.

-- 
Brian Reynolds                  | "Dee Dee!  Don't touch that button!"
reynolds@xxxxxxxxx              | "Oooh!"
http://www.panix.com/~reynolds  |    -- Dexter and Dee Dee
NAR# 54438                      |       "Dexter's Laboratory"


 

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