PanoTools:
Re: entrance pupil - nodal point and C-O-C factor
Dave 360texas.com 2004-Nov-11 01:47:09
BTW.:
Quote "There is not only one aperture inside each lens. There are
several designed to minimize stray light. Any of them could be the
one limiting the diameter of the pencil of rays if you don't stop
down. Would this mean that the "no parallaxe point" moves if I stop
down?" /Quote
I agree there is only 1 aperature device inside each lens. Because
it it a mechanical device that permits the camera owner to dial in
the F-Numbered like F-11, 16, 8 etc. Dialing in the F-stop number
allows the depth of field to be changed. Hence the Circle of
Confusion factor to come into play.
Dave @360Texas.com
--- In #removed#, "Erik Krause" <#removed#>
wrote:
> On 10 Nov 2004 at 22:52, John Houghton wrote:
>
> > > On 10 Nov 2004 at 8:59, John Houghton wrote:
> > > Sorry, but from optical geometry this can not be true. You
don't
> > > change refraction by putting an aperture somewhere, hence you
can not
> > > modify the location of nodal point with this technique.
> >
> > I did say that this did not change the position of the nodal
point.
> > It is nevertheless the case that if you experimentally determine
> > the "no parallax" point, it corresponds to the position of the
> > aperture, not the nodal point. Try it yourself.
>
> I'll do it, but first off all please tell me the exact settings
you
> used. And please could you explain the theory why the "no
parallaxe"
> point should corresponds to the position of the aperture? This is
> contradictory to all I learned about geometrical optics and what
> proved to be true all the time...
>
> BTW.: There is not only one aperture inside each lens. There are
> several designed to minimize stray light. Any of them could be the
> one limiting the diameter of the pencil of rays if you don't stop
> down. Would this mean that the "no parallaxe point" moves if I
stop
> down?
>
> best regards
> --
> Erik Krause
> Ressources, not only for panorama creation:
> http://www.erik-krause.de/
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