Imagery: Auto - Large Table of Contents

EXCERPT page containing first few paragraphs. 2020-01-22 09:05:46

“Bird’s Wing” bokeh
Zeiss ZM 35mm f/2 Biogon @ f/2

Bird-wing Bokeh

Many wide angle lenses exhibit what looks like a flock of birds with outstretched wings.

This type of aberration makes nighttime shooting wide open problematic, because the points of light are so strongly misshapen. The effect grows stronger away from the center of the frame.

Some might not call this bokeh, since it’s not actually blur— it’s in focus. But the term bokeh is not so useful if it must exclude such steep departures from reality.

This image shows a strongly aberrated point source. The point sources are no longer points, but have become bizarre flocks of flying creatures; moths or birds.

This effect is very common at wide apertures off the optical center. Night-time photographers might find this effect very objectionable, but for normal daytime photos the only ill effect is a reduction in contrast due to the smearing.

Article continues for subscribers...

Diglloyd Making Sharp Images is by yearly subscription. Subscribe now for about 13 cents a day ($50/year).
BEST DEAL: get full access to ALL 8 PUBLICATIONS for only 68 cents a day ($249.95)!

Diglloyd Making Sharp Images articulates years of best practices and how-to, painstakingly learned over a decade of camera and lens evaluation.

Save yourself those years of trial and error by jump-starting your photographic technical execution when making the image. The best lens or camera is handicapped if the photographer fails to master perfect shot discipline. High-resolution digital cameras are unforgiving of errors, at least if one wants the best possible results.

  • Eases into photographic challenges with an introductory section.
  • Covers aspects of digital sensor technology that relate to getting the best image quality.
  • Technique section discusses every aspect of making a sharp image handheld or on a tripod.
  • Depth of field and how to bypass depth of field limitations via focus stacking.
  • Optical aberrations: what they are, what they look like, and what to do about them.
  • MTF, field curvature, focus shift: insight into the limitations of lab tests and why imaging performance is far more complex than it appears.
  • Optical aberrations: what they are, what they look like, and what to do about them.
  • How to test a lens for a “bad sample”.

Intrigued? See Focusing Zeiss DSLR Lenses For Peak Performance, PART ONE: The Challenges, or (one topic of many) field curvature.

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2019 diglloyd Inc, all rights reserved.