Re: Pinhole camera

[roger haar <haar@soliton.physics.arizona.edu>]

On Sat, 28 Jun 1997, Donald E. Simanek wrote:
> On Fri, 27 Jun 1997, roger haar wrote:

> > 	Several of us have been discussing the pinhole camera.  We 
> > disagreed on using the terms "image" and "focus" in conjuction with
> >  ...

> > 	Advanced optics text refer to the mapping from the image space to 
> > the object space and imply a one-to-one mapping.  A pinhole camera is a
> > many-point-to-many-point mapping and is either some extreme limiting case
> > of the acceptable mapping or it just does not form an image.
> >  ....
>
> Does the image formed by a single lens even deserve to be called a
> one-to-one mapping? After all it loses 3-D depth information. A hologram
> does depth, but has limitations of resolution, and other problems that
> lens images do not.

**********************

	I think a point concerning the mapping may have been missed.  It 
is a mapping from one space (Not a plane) into another space.  A pinhole 
because of its infinite depth of field maps all of the object space on to
the plane of its screen, but the screen can be in an infinite number of 
positions.  Thus any point in the object plane is mapped to an infinite 
number of points in the image space and vice versa. (All assuming perfect 
geometric optics.)

Thanks
Roger Haar