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 […]

Testing UV Filter Quality

Equipment

My Not Quite Complete Protective Filter Article

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Well, I’ve written (with some misgivings because it has a tendency to create rioting in the streets) several articles about protective filters. Articles that say sometimes you shouldn’t use protective filters, and others that say sometimes you do need to use protective filters, and most recently, one showing how cheap filters can ruin your images. Because […]

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