Nikon Nikkor 20mm f/2.8 Ai-S - Nikon F Mount

The Nikkor 20mm f/2.8 Ai-S is a compact, manual-focus wide-angle lens known for its Close Range Correction (CRC) system. This system ensures high image quality even at the minimum focusing distance of 0.25m. With its robust all-metal construction and 62mm filter thread, it remains a favourite for landscape photographers and photojournalists who prefer a mechanical feel and reliable performance on both film and digital Nikon bodies. Inspect the lens for any stiffness in the focus ring, which may indicate dried lubricant. The CRC system involves moving internal elements, so ensure the focus action is smooth throughout the range. We check for oil on the aperture blades and ensure the rear mount is not excessively worn, as this can affect the accuracy of the aperture indexing on Ai-compatible cameras.