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Overview of Leica 21mm f/2 Super-APO-Summicron-SL ASPH
The about $5195 Leica 21mm f/2 Super-APO-Summicron-SL ASPH is a strongly wide angle lens.
- Full-Frame
- f/2 to f/22
- Dual Synchro Drive AF Motor
- Fast Ultra-Wide Prime
- 3 Aspherical Elements
Performance
Optical performance is ultra-high as per its MTF chart, mimicking its 28/2 sibling but with significantly less consistancy across the frame.
As with its 28/2 sibling the 21/2 most likely has strong distortion requiring distortion correction, which degrades sharpness significantly, unlike its 35/2 sibling which is a ~zero distortion lens. Since Leica hides the optical distortion from us (not included in datasheet, violating decades of precedent), it is hard to assess without field shots. This is surely not an accidental omission, a dog that is not barking.
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