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EXCERPT page containing first few paragraphs. 2023-03-25 03:18:46

Pentax DA HD Limited 15mm f/4 ED

Aperture Series: Ice on Beaver Pond at Sunrise (Pentax K3)

Pentax K3, shake reduction off.

This aperture series evaluate the Pentax HD Limited 15mm f/4 on a real-world subject. See the general notes in the Sidelit Barn example.

Focus placement

There scene is demanding because there is a need for considerable depth of field and yet even on APS-C this is a tough order given the foreground to background distance and small details.

To maximize depth of field over the desired range, a well-considered placement of focus is critical. But at the time it was my very first usage of the 15mm f/4, and I was unaware of the very strong tendency to sharpen the edges and corners well forward of the focus at center; this appears to be a very strong forward field curvature at the periphery possibly also accompanied by an moderate forward focus shift!

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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.

Aperture series 4, 5.6, 8, 11, 12 available in full article

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