EXCERPT page containing first few paragraphs. 2024-04-23 00:47:45
UA_SEARCH_BOT_compatible_botmozilla/5.0 applewebkit/537.36 (khtml, like gecko; compatible; claudebot/1.0; +claudebot@anthropic.com) @ 3.135.183.187
For full access, subscribe here. Or click title to login. 
Examples with 50mm Lenses
See also Case Study with Two Leica 24mm Lenses.
The optical designs of most 50mm lenses are very similar, and nearly all show field curvature which is easily misinterpreted as a lens being “soft”.
I tested eight different 50mm lenses from Nikon, Canon, Zeiss, Olympus and Sigma, and found that all had field curvature that became obvious with the appropriate subject matter. I did so because in my testing of the Zeiss ZE 50m f/1.4 Planar I detected strange variations in image sharpness across the frame, even at f/5.6. At first I thought this was a bad lens, but subsequent testing of the eight 50mm lenses showed this to be common, but generally more visible in the Zeiss Planar design because of its outstanding contrast!
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 about 75 cents a day!
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.
