🚀 go-pugleaf

In article <1992Jul21.190705.15174@midway.uchicago.edu>, jmb1@quads.uchicago.edu (james michael balter) writes:
|> I had an early CCD camera.  One way to expand the dynamic range is to
|> take two images, each at different iris settings (or, with radiographs,
|> different intensities on the light box).

(words deleted)

Combining images taken with different iris settings isn't always a good idea.
As you know, changing the aperture of a camera changes its depth of field.  So,
what was in focus in the small-aperture image may not be in focus in the
large-aperture image.  If the scene is just a plane perpendicular to the
optical axis, and if the camera is well-focused on this plane, then this won't
be a problem.  But, if the scene has some varying depth to it, then some
parts of the image will look more blurry in the large-aperture image.  This
is a noticeable effect, and has actually been exploited by Pentland at MIT for
doing "depth from defocus".

							John Krumm
							The Robotics Institute
							Carnegie Mellon University