Page 221 - Modern Optical Engineering The Design of Optical Systems
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204 Chapter Nine
ANSWER: From Eq. 9.20 z 0.61 0.00055/NA 0.0003355/NA
(a) NA 0.25, z 0.001342 mm
(b) NA 0.80, z 0.000419 mm
(c) NA 1.20, z 0.000280 mm
12 (a) What diameter must a telescope objective have if the telescope is to
resolve 11 seconds of arc? (b) If the eye can resolve 1 minute of arc, what power
is needed to utilize this resolution?
ANSWER: (a) From Eq. 9.22 11 5.5/D and D 5.5/11 0.5 in.
(b) For 11 second to be seen as 1 minute, the power must be 1 minute/11 seconds
60 seconds/11 seconds 5.5 .
