Imagery: Auto - Large Table of Contents

EXCERPT page containing first few paragraphs. 2021-01-16 00:24:06
UA_SEARCH_BOT_null @ 3.238.70.175

Aperture series 2.8, 5.6, 8, 11, 16, 22 available in full article
Depiction of Airy disc

Enable javascript for this site to show Retina images, aperture series, image toggles, topics page menus and more.

Influence of Pixel Size

When rays of light pass through an opening (e.g., a lens diaphragm), they form a wavefront interference pattern know as the Airy disc (Huygens-Fresnel principle).

The Airy pattern with all of its rings has an identical shape for any perfect lens with a round aperture. The only thing that changes with stopping down is the size of the Airy pattern, scaling linearly with the f-stop. This assumes a perfect aberration-free lens.

As the hole (lens diaphragm) becomes smaller (“stopping down”), the scattering effect increases; this causes a drop in contrast. At the same time, the Airy disc steadily becomes larger, with its diameter placing a fixed limit on resolution at any given aperture.

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.

   

   
Depiction of Airy disc size relative to photosite size for apertures f/2.8, f/5.6, f/8, f/11, f/16 and f/22.
Note how the Airy disc begins to cover more than one photosite at apertures f/8 and smaller.
The diffraction limit is reached when two Airy discs overlap by half their diameter.

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.