Author Disassembling the Lumix S Pro R70-200mm f/4 OIS

I'm Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Geek Articles

Disassembling the Lumix S Pro R70-200mm f/4 OIS

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We’ve been impressed with most of the lenses that have come out for the L mount cameras but haven’t taken many of them apart. But as luck would have it, we have several Panasonic Lumix Pro 70-200mm f/4 OIS lenses needing repairs for autofocus issues. In the U. S., Panasonic doesn’t offer repair really, just […]

History of Lenses

Geek Articles

A Brief History of Early Lenses: Part 1

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We are all recent-centric. We tend to think the technology we use didn’t exist until last year or so, even though the roots of it go way back. Phone apps are a great example. I have a dozen little apps on that phone that do things like calculate depth of field…

Why Lens Manufacturers make Specific Lenses

Geek Articles

Why Manufacturers Make a Specific Camera Lens

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There is a lot of online discussion about why a manufacturer made this lens when they so obviously needed to make that other lens. Or why this manufacturer’s design is better than that manufacturer’s magical solutions. So, I thought I’d share the second-hand information I have about the process because it’s probably better than the made-up speculation I read online.

Other

Selecting the Proper Brick Wall for Photographic Tests

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Many amateurs test their lenses by taking pictures of the nearest brick wall without logically thinking about what information that particular wall provides. Done properly, a brick wall test can provide a superb evaluation of your lens. But a poorly done brick wall test is really no better than taking cat pictures without first measuring whisker length and diameter. […]

Lenses and Optics

Sony FE 20mm f/1.8 G Optical Tests

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I haven’t published much optical testing in the last year for many reasons; some obvious, some not. But published or not, we still test things, and occasionally something comes up that I think I need to write up. The Sony FE 20mm f/1.8 G is one of those things. As wide-angle primes go, it’s reasonably priced […]

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