Nikon 20mm f/2.8 AF
Check availablity: eBay.
This lens uses the same optical formula as the manual focus AI-S version, but coatings is probably improved. The AF and AF-D versions are optically equivalent.
It features Nikon's CRC (Close Range Correction). Still, on FX, this lens han some corner softness, vignetting, field curvature, in particular when focusing close. You need to stop down a few clicks to f/5.6 if you want corner sharpness and no vignetting. This is bad for a lens most people would buy for the f/2.8 maximum aperture. Flare and ghosting is well controlled, but CA need to be corrected in post-processing. Colour and constrast is excellent. On FX, it also has difficult to correct distortions, with barrel distortion in the centre and almost no distortion at the edges.
Mechanical construction is fair. The auto focus is fast and precise.
Unless you don't care about corners, you should let this pass on this on FX. It will perform much better on DX, but then it is not an ultra-wideangle any more.
Accepts the HB-4 hood (bayonet).
Rating: Ed: 45, User: - (normalized, 0=useless, 50=average, 100=excellent).
Mount: Nikon F.
Aperture range: f/2.8 to f/22.
Close focus distance (CFD): 26 cm / 0.85 ft (from sensor plane).
CFD magnification: 1:8.3 / 0.12X.
Focus: AF (requires in-body focus motor).
Filter diameter: 62 mm.
L x D, W: 54 x 69 mm, 260 g.
IR: No hotspot reports.
Discontinued: 1989, replaced by: Nikon 20mm f/2.8 AF-D.
Nikon is a multinational corporation headquartered in Tokyo, Japan specializing in optics and imaging. Its products include cameras, lenses, flash units, scanners, binoculars, microscopes, measurement instruments, and steppers (used in semiconductor fabrication). The company was founded in 1917 as Nippon Kōgaku Kōgyō Kabushikigaisha (Japan Optical Industries Corporation), and renamed Nikon Corporation, after its cameras, in 1988. Nikon Corporation is one of the companies of the Mitsubishi Group.