单词	pentaprism
释义	pentaprism /ˈpɛntəprɪz(ə)m / noun A prism having a five-sided cross section with two silvered surfaces, giving a constant deviation of all rays of light through 90°, used chiefly in the viewfinders of single-lens reflex cameras.DSLR (Digital Single Lens Reflex) by definition have optical viewfinders, usually consisting of a instant-return mirror and a pentaprism.... I was just looking through my junk bin over the weekend and I found that I have a number of pentaprisms taken out of 35mm SLR cameras. Pros, from what I've read, is that mirror pentaprisms are lighter, can be made smaller to save space, and are cheaper to manufacture than glass pentaprisms.
随便看	Pacino, Al pack packability packable package packageable package deal package dealer package holiday packager package store package ticket package tour packaging pack animal pack a punch pack a sad packaway packboard pack-cinch packcloth pack drill packed like sardines packed lunch packed out

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