Kalli nassin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar nassin: Passage: A blink comparator wani na'urar kallo ne da masana taurari suka yi amfani da shi don gano bambance-bambance tsakanin hotuna biyu na sararin dare. Ya ba da damar sauyawa da sauri daga kallon hoto guda zuwa kallon ɗayan, "blinking" gaba da gaba tsakanin biyu da aka ɗauka a yanki ɗaya na sama a lokuta daban-daban. Wannan ya ba mai amfani damar sauƙaƙe abubuwa a sararin dare waɗanda suka canza matsayi. Wani lokaci kuma ana kiranta da microscope mai walƙiya. Carl Pulfrich masanin kimiyyar lissafi ne a Carl Zeiss AG, sannan ya kafa shi a matsayin Carl-Zeiss-Intiftung, a cikin 1904. Hotunan da aka ɗauka a cikin 'yan kwanaki kaɗan, abubuwa masu saurin motsawa kamar su asteroids da comets za su yi fice, saboda za su bayyana suna tsalle-tsalle tsakanin matsayi biyu, yayin da sauran taurari suka kasance a tsaye.
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