Category » Roger’s Ramblings

Equipment

Testing Lenses: Best Individual Focus MTF Curves

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OK, in the last post we did something useful, but rather boring: we looked at how MTF changes when lenses are stopped down. Today we’re going to use a more powerful optical bench tool, the MTF vs. Field vs. Focus. Unless you work in a metrology lab (and probably not even then, very few are performing […]

Testing Circular Polarizers

Equipment

My Last Circular Polarizer Post

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I posted an article about circular polarizing filters recently, letting you see some data I obtained for Lensrentals when they were reviewing which of the polarizing filters were among the best. I concluded that they all polarized light really well. I also said that none of the CPs I tested seemed to cause optical problems at […]

Taking apart a Minolta Lens

Equipment

The Minolta 40-80mm f/2.8 Gearbox Zoom; The Clockwork Lens

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There were giants in the earth in those days . . . They were mighty men, men of renown.  Genesis 6:4 I’ve always been fascinated by the history of lenses. I write about it a lot. To me, the most fascinating items are those made many years ago, with what we would consider wholly inadequate technology, which did things […]

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