Errors with Nikon Contrast-Detect Autofocus
Zoomed-in with Live View mode, contrast-detect autofocus solves focusing problems, right? Wrong.
My new case study of contrast-detect autofocus in Making Sharp Images shows a disturbing error (repeatable with ease), and this study is only one of many times I have observed such errors with a variety of lenses and camera bodies.
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The Nikon 14-24/2.8G is driving me crazy. I’ve shot 4 comparisons against the Zeiss 15mm f/2.8 Distagon, but I’m not satisfied with any of them just yet; I really don’t like to show comparisons until I fully understand all the nuances.
Between focus error and focus shift, the Nikon 14-24/2.8G is one maddening lens to shoot, albeit a very sharp one if things work out.
By comparison, the Zeiss 15mm f/2.8 Distagon is a pussycat— easy focus, no focus shift, you get what you aimed at. The Nikon 14-24 certainly is no less sharp, and might even be sharper over the frame, but it’s problematic to consistently place the zone of sharpness where one wants it. The 36MP D800E makes this far more of an issue than ever before, but even my 24MP D3x comparisons show a serious problem in that regard.
