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+50 ℃ IP Paging System (14 ℉
+50 ℃ IP Paging System (14 ℉
Whenever a very well-corrected lens is applied in place of a pinhole, the geometrical ray divergence is eliminated via the focussing action of the lens, plus a much bigger aperture could possibly be employed; in that circumstance the diffraction spreading gets to be small indeed. The impression of some extent shaped by a wonderful lens is really a