Nikkor-UD 20mm f/3.5 Quick Review Nikon Nippon Kogaku
This is a large ultra-wide from the film days, which translates into a nice wide angle on APS-C. Does it get lost in translation?
Since this lens is for a 135 format film camera, it is fairly large for a wide angle on APS-C, especially when you add the adapter. The lens has 11 elements in 9 groups, and has an 7 slightly curved bladed diaphragm. The minimum focus distance is a short 0.3 m (1 ft), and is dense at 390 g (13.8 oz). Filter threads are 72 mm.
Comments on the Results
This lens performs acceptable for a wide angle lens, especially if you stop down. Center performance is great at all apertures, but corners aren’t good until around f/8. This lens performs maybe a bit better than the Sony 16mm f/2.8, but not a lot, and the Sony has a huge size and weight advantage.
Distortion is noticeable, but not extreme at -1.7% barrel (numeric average for all apertures).
Lateral CA is not well controlled and is visible on shots.
Coma is very noticeable wide open, and improves by f/5.6. Astigmatism is visible in the corners. The bokeh circles are oddly shaped near the edges wide open.
There is some purple fringing wide open, but it is mostly gone by f/5.6.
Measured focal length at 1:53 magnification: 22mm
Pros and Cons
- Center Performance
- Build Quality
- Corners/partway up until f/8