Category: Lenses and Optics
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MTF Tests of the Sony FE 24-105mm f/4 OSS
Obviously, I have angered the Lens Testing Gods, since for the second post in a row I’m testing 24-105mm f/4 lens; this time the Sony 24-105mm f/4 OSS lens. As I’ve mentioned in the post on the Sigma 24-105mm f/4 many initials Art lens, while these are indispensable photographic tools, I despise…
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MTF Testing for the Sigma 24-105mm f/4 DG OS HSM Art Series Lens
I generally let you know what my expectations are before I start, to hopefully let you know where my personal opinion affects things. The fact that I’m just posting tests of the Sigma 24-105mm f/4 DG OS HSM Art months after the lens was released tells you a lot. I’m not excited about testing…
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Finally, Some m4/3 MTF Testing: 25mm Prime Lens Comparison
This blog is a little different. It’s geekier than most, of course. Also, I don’t use it to make income, and that makes it a bit scattered. A mainstream blog has to cover all the hot topics. I get to cover what I’m interested in at the moment. More importantly, I don’t have to cover everything, so…
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MTF Testing the Canon 85mm f/1.4 L IS
The Canon 85mm f/1.2 II lens, the king of creamy bokeh, is basically a 40-year old optical design first released in 1976 (in FD mount) and released as an EF mount lens after some slight optical modification in 1989. The “II” version, released in 2006, was an electrical/mechanical change only, the…
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Testing Lenses: Finding The Best Average Focus Point
You have been patient, my friends. You have made it through the first article, where we looked at how MTFs improve stopped down and saw it was a bit different for every lens. You enjoyed the second article, where we looked at the Best Individual Focus MTF (BIF MTF) which showed how good the MTF…
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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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Canon’s Holy Grail – Using the Canon 200mm f/1.8 L USM
Certainly, you’re probably aware of Canon’s 85mm f/1.2L, and the Canon 50mm f/1.2L, but Canon has a long history of incredibly fast lenses, many of which that have since seemingly disappeared off of the face of the Earth. Many of them are now called the Holy Grails of Canon Glass and for legitimate…
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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.
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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_**
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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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Cine Lens Comparison: 35mm Full-Frame Primes
Good day! And welcome to our first Cine lens MTF comparison. If you aren’t familiar with what we do here, I suggest you take a glance at our previous post on why we’ve started testing Cine lenses. For those of you who haven’t been here before, let’s be clear about what this is not. It is not a lens…