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EXCERPT page containing first few paragraphs. 2022-01-25 11:26:00

85mm: vs 70-200/4L IS, 85mm /1.2L II, 85mm f/1.8

Important details on the introduction page should be read prior to viewing these crops. Those details are not repeated here.

Zone of focus

The same 70-200mm f/2.8L IS II is shown twice in the crops that follow. That’s because a very small focus difference can scarcely be detected at the point of focus, but the zone of sharp focus at f/2.8 does shift, and the left edge is visibly blurred with one series. Such are the changes caused by small focus nuances.

In this case, it shows that the lens is not symmetric, since the right side remains mostly unchanged. It shows that there is not perfect alignment left-to-right, not too surprising for such a complex lens. With most photos, this won’t show up, since subject matter is not planar, but consider that the left-edge blur requires f/8 to overcome, and it no longer seems a nit-picker issue at all.

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Diglloyd DAP is DSLR-oriented, but also contains workflow and other topics. Much of the focus is on Canon and Nikon but also Pentax and Pentax medium format.

Special emphasis is placed on lens evaluation, focusing on Canon and Nikon and Sigma lenses, but with a few others like Rokinon/Samyang.

  • Make better images by learning how to get the best results right away.
  • Save money by choosing the right lens for your needs the first time, particularly some of the new Sigma Art lenses vs Nikon and Canon.
  • Workflow discusses image organization, raw conversion and post processing. Many examples show processing parameters for direct insight into how the image was converted.
  • Jaw-dropping image quality found nowhere else utilizing Retina-grade images up to full camera resolution, plus large crops [past 2 years or so].
  • 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 Nikon or on Canon or on Pentax.

Click to view aperture series for all lenses

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