This is
interesting. I use the fancy manfrotto QTVR set up with levelling head
and 2-axis displacement sliding arms etc.
I have done some experimentation with different lenses and I think
you're on to something here.
I must go back and look at the numbers more carefully because when I
first started using it I used a 50mm lens and calculated where the
nodal point was, then used that as a starting position and it wasn't
quite right. I attributed this to errors in my measurements and the
fact that lenses for 35mm cameras had complicated optical arrangements
etc.
But it makes sense to me, geometrically at least, that it's some other
(Exit pupil point?) place. How do you calculate the position of the
exit pupil... is it the aperture? I used the broomstick experiment
that Walter talked about... which gave me what I wanted in a rather
"Analogue" way
You can see a couple of 360 degree spherical panoramas at
www.herschelmair.com/sinaw/sinaw1.mov
www.herschelmair.com/sinaw/sinaw2.mov
www.herschelmair.com/sinaw/sinaw3.mov
Herschel
So the camera needs to be rotated about something other than the rear
nodal point
to keep the relationship between foreground and background objects
fixed. This would
be a rotation axis running vertically through the lens at some other
point than the
front or rear nodal point. If I read "stuff" about this correctly this
would be
the center of perspective or the "entrance pupil" of the lens. I call
is a "magical
point" or axis. ;)
Anyway, maybe a list member with experience with tripod heads such as
the Kaidan
can further enlighten us on this topic. No?
andy
PS: written in a hurry just before leaving for a party!!
Ken Sinclair wrote:
Sir Andrew of Rochester,
If my aging memory serves me well enough, I believe I was taught that
the for panoramics (by camera rotation) the 'rotation point' had to
be dirtectly
under the nodal point of the lens.
Now... where did I leave my specs?
Ken
On 11-Apr-09, at 11:38 AM, ADavidhazy wrote:
trolling of course! (forgive me if you can!)
http://people.rit.edu/andpph/text-panoramic-bar.html
again, it turns out it is not new ... written off the
top of my head and there is not much there anymore!
;)
andy
Quando omni flunkus moritati (R. Green)
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