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Science Forum Index » Optics Forum » Mapping images on curved image planes
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| Quantum Ray |
 Posted: Tue Apr 15, 2008 8:51 am |
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Guest
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Hi all,
How do people use an image formed on a curved image plane, like, say,
the image of a patch of night sky containing starts taken by a Schmidt
camera?
My question is that suppose you want to print the sky image in a book,
or show it on a computer screen, since these are flat media, will the
"mapping" between a curved surface and a flat one cause image
distortion?
Thanks
QR |
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| Helpful person |
| Posted: Tue Apr 15, 2008 10:35 am |
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Joined: 22 Jun 2004
Posts: 678
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On Apr 15, 2:51 pm, Quantum Ray <Quantum...@gmail.com> wrote:
Quote: Hi all,
How do people use an image formed on a curved image plane, like, say,
the image of a patch of night sky containing starts taken by a Schmidt
camera?
My question is that suppose you want to print the sky image in a book,
or show it on a computer screen, since these are flat media, will the
"mapping" between a curved surface and a flat one cause image
distortion?
Thanks
QR
In general one does not actually have a curved (spherical) image plane
because (except for fiber faceplates) detectors are not curved. There
will usually be a field flatener in front of the image plane. |
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| Quantum Ray |
| Posted: Tue Apr 15, 2008 10:51 am |
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Guest
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On Apr 15, 1:35 pm, Helpful person <rrl...@yahoo.com> wrote:
Quote: On Apr 15, 2:51 pm, Quantum Ray <Quantum...@gmail.com> wrote:
Hi all,
How do people use an image formed on a curved image plane, like, say,
the image of a patch of night sky containing starts taken by a Schmidt
camera?
My question is that suppose you want to print the sky image in a book,
or show it on a computer screen, since these are flat media, will the
"mapping" between a curved surface and a flat one cause image
distortion?
Thanks
QR
In general one does not actually have a curved (spherical) image plane
because (except for fiber faceplates) detectors are not curved. There
will usually be a field flatener in front of the image plane.
Actually the image plane (and the recording media, such as
photographic film) is curved for a Schmidt sky survey camera....both
the mirror and the image plane are spherical.
QR |
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| Helpful person |
| Posted: Tue Apr 15, 2008 12:02 pm |
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Joined: 22 Jun 2004
Posts: 678
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On Apr 15, 4:51 pm, Quantum Ray <Quantum...@gmail.com> wrote:
Quote: On Apr 15, 1:35 pm, Helpful person <rrl...@yahoo.com> wrote:
On Apr 15, 2:51 pm, Quantum Ray <Quantum...@gmail.com> wrote:
Hi all,
How do people use an image formed on a curved image plane, like, say,
the image of a patch of night sky containing starts taken by a Schmidt
camera?
My question is that suppose you want to print the sky image in a book,
or show it on a computer screen, since these are flat media, will the
"mapping" between a curved surface and a flat one cause image
distortion?
Thanks
QR
In general one does not actually have a curved (spherical) image plane
because (except for fiber faceplates) detectors are not curved. There
will usually be a field flatener in front of the image plane.
Actually the image plane (and the recording media, such as
photographic film) is curved for a Schmidt sky survey camera....both
the mirror and the image plane are spherical.
QR- Hide quoted text -
- Show quoted text -
Traditionally that's true. |
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| Guest |
| Posted: Tue Apr 15, 2008 6:01 pm |
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In general, on axis, the picture should be nearly diffraction limited,
aka as good as you can get without violating classical optics.
But as you go off axis from the object the picture quality will fall
off.
A curved image field can result, field curvature can result which can
be corrected for using a curved detector. I know back in the old days
for applications in aerial photography the film plane was curved to
reduce the effects of field curvature. By playing around with lens of
negative power and index you can reduce this affect.
I can't speak for how its done digitally. |
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