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Autofocus Inconsistency, Backfocus, Manual Focus

Like many mirrorless cameras, the Leica X Vario has a fundamental algorithmic flaw in its autofocus: it focuses with the lens stopped down to the shooting aperture. Compare that idea with opening the lens diaphragm to focus precisely, then shooting at the stopped-down aperture (as with all DSLR cameras).

This stopped-down autofocus algorithm not only affects focus accuracy, it actively degrades autofocus performance as the lighting dims, a problem I encountered repeatedly in the field. At times, the focus was unable to lock on at all unless I opened the aperture fully.

With the lens stopped down, a deeper zone of sharp focus is obtained (depth of field), and the camera cannot then distinguish the optimal focus, with the result that the near-far positioning of the zone of focus can be skewed in undesirable ways: a blurry foreground and too-sharp background or vice versa—all while the chosen point of focus is just as sharp either way (or maybe not, as we shall see).

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Since 2009, Diglloyd Guide to Mirrorless covers mirrorless cameras and lenses. Includes interchangeable lens camera systems (Sony, Fujifilm, Olympus, etc) as well as fixed-lens cameras (Sony, Sigma, Ricoh, etc).

In addition to the manufacturer-brand lenses, lens coverage includes 3rd-party lens lines like Zeiss Touit, Zeiss Loxia and Zeiss Batis.

It includes hundreds of pages of exclusive coverage and high resolution, Retina-grade examples for the new mirrorless camera systems from Sony, Fujifilm, Olympus, Sigma, Ricoh and more. Also included are operational concerns, like shutter vibration or other camera behaviors. This publication will play a decisive role in your selection and use of mirrorless cameras and lenses.

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