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Sony A7R III
Sigma 14-24mm f/2.8 DG DN Art

Distortion @ 14mm

This page looks at correction of the barrel distortion at 14mm and how much the image must be cropped after correction. The Adobe Camera Raw correction factor is also shown.

The distortion at 14mm is moderate and entirely in line with most lenses of its focal length, so the Sigma 14-24mm f/2.8 DG DN Art might be praised in keeping distortion this low for a zoom lens.

Example @ 14mm

Sample with serial number xxxx6274.

In the center, there is a loss of 7% in terms of pixel count, that is, the pixels must be compressed so that 42MP resolution becomes in effect 39MP resolution in the center by elimination of pixels per unit area. The micro contrast is subtly decreased. The outer zones are a bit less affected but lose micro contrast also.

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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.

  • Make better images by learning how to get the best results right away. For example, the best way to set up your Sony camera.
  • Save money by choosing the right lens for your needs the first time, particularly with the numerous lenses available for Sony.
  • Make better images, a sort of “cheat sheet” saving yourself months or years of ad-hoc learning—best practices and how-to and processing parameters are discussed and shown.
  • Jaw-dropping image quality found nowhere else utilizing Retina-grade images up to full camera resolution, plus large crops.
  • Real world examples with insights found nowhere else. Make sharper images just by understanding lens behavior you won’t read about elsewhere.
  • 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.

Want a preview? Click on any page below to see an excerpt as well as extensive blog coverage, for example on Sony.

Variants Uncorrected,Corrected,CorrectedCropped available in full article
f8 @ 0.6 sec pixel shift null, ISO 100; 2019-09-03 19:26:15
Sony A7R III + Sigma FE 14-24mm f/2.8 DG DN Art @ 14mm RAW: LACA corrected

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