Category: Technical Discussions
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Autofocus Reality Part 1: Center-Point, Single-Shot Accuracy
Once upon a time I wrote an article attempting to explain phase-detection autofocus Works") and its limitations. That was a lot like trying to explain what happened to the Mary Celeste or why Stonehenge was built. Actually we probably have a better handle on the Stonehenge thing than we do on the…
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Canon’s 18-135mm IS gets an STM Makeover
So the usual happened today: I read in a couple of places that the Canon 18-135mm IS STM lens isn’t going to be available in the U. S. for a while. A few minutes later Tyler walks in my office with one, asking if I want to test it. Let me be clear where I’m coming from: we never stocked the Canon…
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Optically Adjusting a Lens
I write a lot about the fact that every copy of a lens is slightly different than every other copy. Now don’t get me wrong: I’m talking slight differences that are barely detectable, not good or bad. Even when things appear to be in the “bad lens” area, they usually aren’t. The majority of the time…
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Guest Blogger Aaron Nace | How to Capture the Real & Surreal with a Superlative Lens
_Today’s Guest Blogger Aaron Nace is going to show you tips on creating and compositing fantastical images with a lens he considers to be one of the best._ _Aaron is a Chicago-based photographer and retoucher who combines elements of reality and fantasy to create his images. Aaron has taught…
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5D Mk III AF points and 3rd Party Lenses
First, for those of you who aren’t aware, the new AF system in the Canon 5D III has different available autofocus points with different lenses. Canon has listed all of their lenses in the 5D III manual (pages 78-84 for those of you who don’t do manuals much) telling you which of the 61 AF points…
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Sensor Size Matters – Part 2
### Why Sensor Size Matters Part 1 of this series discussed what the different sensor sizes actually are and encouraged you to think in terms of the surface area of the sensors. It assured you the size of the sensor was important, but really didn’t explain how it was important (other than the…
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Sensor Size Matters – Part 1
We get a lot of questions about sensor sizes and crop factors. Most people know the difference between a standard (APS-C) crop sensor and a full-frame sensor. Not many, though, know how much smaller a 2/3” sensor is than a 4/3 sensor, and fewer still the difference between those and a 1/1.8”…
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The Limits of Variation
A few people were more than a little amused that I, the ultimate pixel-peeper, wrote an article demonstrating that all lenses and all cameras vary a bit; that you can’t find the ultimately sharpest lens. Each individual copy of a given lens is a little different from the other copies. A single copy…
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Good Times with Bad Filters
OK. First and foremost this is a fun post. It is not episode 362 of “Should you put a UV filter on your lens”. Some people use them. Some don’t. There’s not enough bandwidth to ever end that argument. But here at Lensrentals, we have a ton of filters. We have some really good, very expensive…
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The Glass in Front of Your Glass: All About Filters
In the ancient days of film, any photographer worth his flash bulbs had a large set of filters in his bag. Filters to correct light, enhance contrast, add special effects to his images, you name it, there was a filter for it. Then came Photoshop and RAW and filters became quaint. Many of them,…
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How Autofocus (Often) Works
Clarke’s Law: _Any sufficiently advanced technology is indistinguishable from magic_. Arthur C. Clarke Clark’s Law: _Any sufficiently advanced cluelessness is indistinguishable from malice_. J. Porter Clark ## My Apologies Nothing in online forums demonstrates the two laws above better than…
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Lens Repair Data 3.5
## What Is This? It is our practice to publish our lens repair data every 6 months (data published in May of 2009 is shown in Lens Repair Data 3.0). We started it at the request of some customers who felt that the large number of lenses we deal with and the harsh conditions they are subjected to…
