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Panasonic Leica DG Summilux 15mm f/1.7 ASPH

Focus Shift at Close Range (Olympus EM1, Dolls)

This series confirms a pronounced rearward focus shift with the 15/1.7, which is hugely destructive to image sharpness if not accounted for.

Dolls

Two large actual pixels crops are provided.

Both crops provide near-to-far context showing a pronounced rearward focus shift with stopping down. On the MFT format, depth of field is deep (see format depth of field), so to see this visible a shift is surprising. In your author’s view, significant focus shift is an unacceptable design tradeoff, because it is so destructive to image sharpness.

Focus shift aside, observe inadequate control of secondary longitudinal chromatic aberration; that veiling purple/magenta haze seen on the leading block at bottom. Other scenes confirm this weakness; the 15/1.7 can be expected to show pronounced violet fringing on backlit subjects even to f/5.6. This behavior is not a crowd pleaser.

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Diglloyd Guide to Mirrorless offers comprehensive integrated coverage of most APS-C and full frame mirrorless cameras and lenses.

Special emphasis is placed on Sony full-frame, including Sony lenses and the high performance Zeiss Batis and Zeiss Loxia lenses plus Rokinon/Samyang and others. Fujifilm X, Olympus and Panasonic M4/3, Sigma dp Merrill and dp/sd Quattro are also covered in depth. Years in the making, it offers a wealth of material for choosing and using a mirrorless camera.

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  • Aperture series from wide open through stopped down, showing the full range of lens performance and bokeh.
  • Optical quality analysis of field curvature, focus shift, sharpness, flare, distortion, and performance in the field.

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Aperture series 1.7, 2, 2.8, 4, 5.6, 8 available in full article

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