Re: couple of pictures

Think of cutting out a format sized segment from a sphere, just have
to place supports so the film/paper is forced to lay on the sphere's
inside. However, the wheel of cheese approach is good, too, as is a
horizontal cylinder.

Pam

William Erickson wrote:
>
> I've daydreamed a lot about shpeircal film planes but I haven't figured out
> how to do it. You can do one curved in one dimension, though. The radius of
> the curve is the 'focal length" of the aperture. It makes the camera look
> like half a wheel of cheese. In the ones I've made like this there is
> minimal distortion at the edges and its equally sharp all the way around.
> ----- Original Message -----
> From: Pam Niedermayer <pam_pine@cape.com>
> To: <pinhole-discussion@pinhole.com>
> Sent: Tuesday, February 27, 2001 2:51 PM
> Subject: Re: [pinhole-discussion] couple of pictures
>
> > How spherical would the film plane have to be to get to sharp edges?
> > Let's say I'm building an 8x10 pinhole camera (which I am), and wanted
> > to build a special curved film holder. Should the spere be around the
> > distance from pinhole to film center, the pinhole being the center of
> > the sphere?
> >
> > Pam
> >
> > William Erickson wrote:
> > >
> > > I'd guess that edge softness is a product of the fact that the plane of
> > > optimal sharpness is a hemisphere centered aroiund the hole, and the
> film
> > > plane is flat, transecting the optimal image best at the center, or if
> > > rounded, not rounded at the same radius.
> > > ----- Original Message -----
> > > From: Simon Cygielski <simon@wbj.pl>
> > > To: <pinhole-discussion@pinhole.com>
> > > Sent: Tuesday, February 27, 2001 3:56 AM
> > > Subject: [pinhole-discussion] couple of pictures
> > >
> > > > Hi all,
> > > > I've uploaded a couple of my first efforts with my 6x17 cm panoramic
> > > > pinhole camera. They're up at
> > > >
> > > > http://www.pinhole.com/discussion/upload/images/path1.jpg and
> > > > http://www.pinhole.com/discussion/upload/images/phones2.jpg
> > > >
> > > > I built the camera out of a Holga using bookboard to expand it to its
> > > > present size. "Focal" length is 7.5 cm. Any comments would be
> > > > appreciated.
> > > > I also have a question: is the loss of sharpness on the far edges
> > > > inevitable, or can it be corrected somehow? perhaps thinner stock?
> This
> > > > hole was made (fairly carefully) out of a Coke can and sized according
> > > > to some pinhole formula (though I forget which one), so it should be
> > > > somewhere in the ballpark size-wise.
> > > > Thanks,
> > > > Simon
> > > >
> > > >
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> >
> > --
> > Pamela G. Niedermayer
> > Pinehill Softworks Inc.
> > 600 W. 28th St., Suite 103
> > Austin, TX 78705
> > 512-236-1677
> > http://www.pinehill.com
> >
> > _______________________________________________
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> > Pinhole-Discussion@pinhole.com
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> >
>
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-- 
Pamela G. Niedermayer
Pinehill Softworks Inc.
600 W. 28th St., Suite 103
Austin, TX 78705
512-236-1677
http://www.pinehill.com