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Zeiss 15/2.8 Distagon Q&A — Distortion

ZF.2 15mm f/2.8 Distagon T*

This is one of several pages resulting from the March 13, 2012 discussion with Staff Scientist Dr. Hubert Nasse. See the original list of questions.

These pages are a summary of the discussion based on notes taken, and as reviewed by Dr. Nasse. Bracketed comments [ ] are editorial in nature.

Low distortion was a design goal for the 15/2.8 Distagon. In particular, a distortion goal of 2% was desirable, and also to avoid a wave-type distortion as found with the 21/2.8 Distagon (one of its few faults).

The 15/2.8 Distagon succeeds with only 2% barrel distortion, which is usually undetectable by the eye. For critical uses, barrel distortion is straightforward to correct in post processing.

For very close work near to 1:9, the distortion rises, but with such close focusing, the perspective is often the dominating factor. Note that a 1:9 reproduction ratio involves a sensor to subject distance of only 25cm (10 inches), and that affords only 9cm / 3.54" of clearance to the front lens element! Users working at such close range might consider using a filter to protect the front lens element from mishaps.

ZEISS 15mm f/2.8 Distagon relative distortion

 

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