Compact and light, the Nikon 20mm f/2.8 Nikkor AIS Manual Focus Lens has everything. It is built to Nikon’s classic manual focus high standards, offers a fast f/2.8 maximum aperture, rectilinear images (straight lines remain straight) and Nikon’s Close-Range-Correction which maintains image quality at near-focusing distances. This lens is capable of focusing down to 10″ (25cm) for dramatic perspectives.

Reviews

Nikon 20mm f/2.8 Ai-S review by KenRockwell.com

Optically it’s a typical Nikon wide-angle: soft in the corners wide-open due to coma and some light falloff that goes away stopped down. The barrel distortion is a little more complex than usual: the center of the image has the usual barrel distortion, however it starts to straighten out at the far edges. This makes it measure a little better in tests, but also makes it much more difficult to correct in Photoshop.

This lens is much sturdier and precisely built than its optically equivalent AF version.

You could save money and get an AF version for use on your manual focus camera if you don’t mind the AF lens’ sloppier mechanics.

There is no major difference in performance between any of the 20mm lenses tested here.

Autofocus Nikkor 20mm f/2.8D review by bythom.com

Drawbacks

• Expense. This isn’t a cheap lens. Some consumer-oriented zooms are less expensive than the 20mm f/2.8D. Nevertheless, I’d argue that the 20mm f/2.8D is an excellent value. Performance is everything you’d expect at this price.
• Limited depth of field scale. The DOF scale only has markings for f/5.6 and f/11, and the only marked settings (for feet) are 0.85, 1, 1.25, 1.5, 2, 3, 5, and infinity. If you’re setting focus based on hyperfocal or other focus charts, you’re going to find that you’re mostly guessing.

Positives

• Sharp. Excellent sharpness.
• Small and light. Even weight-averse backpackers will have no problems carrying this lens into the backcountry.