Hi Matt,
We aren't real experts on this -- we got our information on this from the web. Here is .
In short, the modulation transfer function describes how much a
piece of optical equipment, say a collection of lenses and/or mirrors,
blurs the image of an object. The lenses and mirrors may not be
perfect, and even if they are, diffraction limits the ability to see
finely spaced features. The standard test is to see how well
alternating white and black stripes show up (that is, their contrast,
the difference between the whitest white and teh blackest black) in the
image, depending on how finely spaced they are. Widely spaced features,
such as broad stripes, don't lose much contrast, since a little
blurring only affects their edges. Stripes that are fine enough will
appear to be a uniform gray after being blurred by the optical
apparatus being tested.
The modulation transfer function appears to be a measure of how
much bright-to-dark contrast is lost, as a function of the width of the
stripes, as the light goes through the optics. So it might be 1.0 for
broad stripes, which are not significantly blurred, and 0.1 for ones
almost too narrow to be viewed with the optics.
Gloria, Mike, and Tom
(published on 10/22/2007)
