Re: Determining Curcuit Angle of View

[Glenn Barry <glenn@xxxxxxxxxxx>]

you are right on the mark with your calculations, but the missing piece of the
puzzle is the focal length of the lens, but it wouldn't be impossible to really
look at the shot and see from the presence or absence of extreme vanishing
points whether not the lens was wide, normal or telephoto. It will at least give
you a ballpark estimation. I can tell the difference between something in the
20mm versus 28mm range for example by looking at the divergence of the planes of
the ground and the sky, if clouds are present. Telephoto compression is
relatively easy to spot also, though not knowing the the original format you
won't be able to use depth of field top judge this one, assuming the shots were
taken at hyperfocal distance.

Glenn

Joe McCary wrote:

> Ok its time for me to step up to the plate and maybe make a big fool of
> myself.
>
> My HS geometry class taught me that the circumference of a circle is equal
> to 2*Pi*Radius.  If I use my Noblex as an example; focal length is 50mm, the
> full circle circumference would be 2*50* 3.14 (pi) for a total of 314mm.
> That would be 360°.  If the  Noblex film is 120mm long (5x12) divide the
> 120mm into the 314mm and you get 2.61 parts of 360°.  Divide the 360 by the
> 2.61 and you get 137°.  That is ABOUT the horizontal angle of the Noblex
> 150.
>
> So, what was the focal length of the lens used to create this 70" panorama?
>
> Joe McCary
> (hopping my logic is not too far off)
>
> ----- Original Message -----
> From: "ADavidhazy" <ANDPPH@xxxxxxxxxxxxxxxxxx>
> To: <panorama-l@xxxxxxxxxxxxxxxxx>
> Cc: <ANDPPH@xxxxxxxxxxxxxxxxxx>
> Sent: Thursday, August 24, 2000 11:43 PM
> Subject: Re: Determining Curcuit Angle of View
>
> > It seems to me this would be fairly difficult to do without any kind of
> > "benchmark". One way to do it would be to go to the origial locations and
> > determine the angle right there ... but, of course, this may not be
> possible.
> > Or get a map of the area and deal with it in a similar way by identifying
> > landmarks.
> >
> > Otherwise ... I myself can not think of a way other than very rough
> > approximation. On the other hand, if they are more than 360 degrees then
> the
> > situation becomes easier! Or if they are almost 360 degrees then it might
> be
> > possible to "fill in the gap" with imagination and deduce an approximate
> angle
> > that way.
> >
> > adios,
> >
> > Andrew  o o  0 0 o . o  Davidhazy, Imaging and Photo Tech
> >          \/\/\/\/\/\/         http://www.rit.edu/~andpph
> > __________|        |_____________________________________
> >
> >
> > > Fellow Panoramic Photographers,
> >
> > > I have been given two, recently reprinted,
> > > circuit panoramic contact prints 10" x 70".
> >
> > > I would like to determine the angle of view
> > > if possible.
> >
> > > Can anyone help me out or point me in the
> > > right direction?
> >
> > > Randy
> >
> >
> >

--
"People are like stained-glass windows. They sparkle and shine
when the sun is out but when the darkness sets in, their true
beauty is revealed only if there is a light within."

Elizabeth Kubler-Ross

Glenn Barry Photography
2/13 Gerroa Avenue
Bayview
N.S.W. 2104
Australia
Ph (612) 9997 3431
Mobile 0415 279 366
E-Mail: mailto:glenn@xxxxxxxxxxx
Web: http://www.acay.com.au/~glenn