where p is the distance from the optical axis (normalized to reach 1 at the edge of the aperture), AC"1" is the total coma aberration, and 6 is the angle from the axis of misalignment (Born and Wolf 1980). The slight amount of astigmatism mixed with this coma has the form appearing in Chapter 14, and the total deformation is w , = W + W . The amounts of each aberration depend on misalign coma astig 1
the aperture and the focal ratio.
6.4. Filtration of a Misaligned Newtonian 107
Fraction of maximum spatial frequency 10-inch (250 mm) f/4.5
Fig. 6-3. Modulation transfer function of steadily worsening Newtonian alignment (45° orientation of MTF target bars with respect to the direction of misalignment).
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