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Lenses and Optics

Canon Illumination Correction and Third-Party Lenses

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I while back I put out a notice that the Sigma 150mm and 180mm OS Macros had an issue if you shot JPGs on a Canon 5D Mk III and left peripheral illumination correction on. The camera auto-corrected for vignetting that wasn’t there, leaving an interesting pattern with a dark center and lightened edges and […]

How To's

A Tilted Element Demonstration

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One thing we preach here a lot is that just because a dropped lens looks fine on the outside doesn’t mean it is fine.┬áThe other thing we preach a lot is that a tiny difference in the centering, tilt or placement of a single element can have a dramatic effect on image quality. Aaron made […]

Technical Discussions

Autofocus Reality Part 3B: Canon Cameras

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Some days it’s good to be a geeky gear-head. This is one of them because a) I finished testing autofocus on all of the Canon camera bodies we had, b) I actually found out some interesting stuff, and c) I got worked up about camera marketers while doing it, so I have my next post […]

Lenses and Optics

Imatest Macro Results (With Apologies to the Nikon 105 VR Micro)

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A few months back we tested a number of Nikon lenses on the D800 cameras, hoping to determine which lenses could bring the absolute best resolution out of that camera’s 36-megapixel sensor. The results were interesting, and in a few cases surprising. More than a few Fanboys went ballistic over minutia, which is always entertaining. […]

Technical Discussions

Autofocus Reality Part 3A: Canon Lenses

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  Sometimes I get to write cool, new stuff. Sometimes there’s just grunt work to be done, usually of my own making. This is one of those times. To bring you up to date if you’ve landed here first, this is how I got here. Autofocus Reality Part 1 showed that on center-point, single-shot autofocus, […]

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