Category: Geek Articles
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Testing Lenses: Best Individual Focus MTF Curves
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…
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Testing Lenses: Stopped-Down MTF Curves
For quite a while now we’ve been publishing our MTF curves. They’ve always been the same thing; at least ten copies of each lens, in 4 rotations, and measured at the widest aperture. The reasons for that are (to us) very straightforward. Our purpose in doing the tests is to establish reasonable…
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About Getting Your Camera Wet… Teardown of a Salty Sony A7sII
People think that because I expect the worst and try to prepare for it, that I’m negative. That’s not it at all. I’m not a negative person; I’m cheerfully cynical. If I expect the worst and it doesn’t happen, I’m happy because things went better than I expected. If I expect the worst and it does…
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The 8K Conundrum – When Bad Lenses Mount Good Sensors
_This is a guest post from Brandon Dube, whose name you’ve seen on many of our articles. In addition to his metrology work, he also does high fidelity numerical optical simulation, and spends his summers at places like NASA/JPL working on the cameras that are going in the Mars 2020 rover._ _This…
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Four Lighting Techniques to Try on your Next Photo Shoot
I’m a lighting guy. Ask any of the higher-ups here at Lensrentals.com, and they can confirm that I’m always pressuring them to get more lighting options available for rent (with varying degrees of success). For me, I was taught that photography translates to the capturing of light on film (or in…
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My Last Circular Polarizer Post
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…
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The Minolta 40-80mm f/2.8 Gearbox Zoom; The Clockwork Lens
**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…
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Looking at Clear and UV Filter Spectrograms
I’ll start by saying, this is not an article – or at least not a complete one. When I wrote My Not Quite Complete Protective Filter Article, I promised to try to add transmission spectrograms so that you could see not just the wavelength I tested for transmission, but also how the rest of the light…
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My Not Nearly Complete, But Rather Entertaining, Circular Polarizer Filter Article
So, a while back I wrote a not quite complete article on UV filters. To do that, I had to buy new testing equipment and learn to test filters. This was not what I wanted to do when I grew up. But somebody has to do it, and I did get to buy new toys. More importantly, Tyler (Who handles the…
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Understanding Camera Log & How It Can Improve Video Workflows
Video imaging techniques historically, have been a battle of compromise between quality and price point but the prosumer digital video market is finally showing signs of bargaining power. In terms of image quality, raw offers unparalleled advantages because you are capturing sensor data rather than…
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Taking Apart the Sigma Cine 85mm T1.5 FF Lens
We’ve been impressed with the Sigma Cine lenses. We weren’t surprised that they’re generally sharper than classic Cine primes; that’s what we’ve come to expect from Sigma. We were pleasantly surprised by the smoothness of focusing and aperture and the apparent build quality. Since we’d previously…
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Taking Apart the Zeiss 85mm T2.1 CP.3 Cinema Lens
Long ago, in an office far, far away we did a teardown of the Zeiss 85mm CP.2 lens. Since we’ve already seen the earlier model, we thought it would be interesting to take a peek inside the new Zeiss 85mm CP.3 lens as well. We’re going to have to work on them eventually, and it’s always good to have…
