Nikon PK-11 Auto Extension Ring - Accessory

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Model Details

Auto extension ring made for Nikon F mount SLR cameras and lenses by Nikon. Has an 8mm extension. Will not meter properly with Pre-AI lenses and bodies. Metal body available in black.

  • Size: 65 x 18mm
  • Weight: 50g
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Nikon F

Nikon introduced their first SLR, the Nikon F, in 1959. Alongside it they unveiled a series of lenses and a new lens mount that would carry them to professional success for the next decades. To this day, all Nikon DSLRs use the Nikon F mount.

In the beginning, Nikon lenses communicated aperture information to the body using a metal coupling fork, affectionately known as "bunny ears". Soon after, Nikon began using a similar system that automatically told the camera the maximum aperture of the lens. This Automatic Indexing (AI) system stuck around for decades in lenses and is still found on Nikon's high-end professional DSLRs even though new lenses communicate this information electronically.

With only minor compatibility issues (don't use a pre-AI lens on AI bodies or modern digital cameras), Nikon F lenses and bodies are pretty much interchangeable.

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Nikon PK-11 Auto Extension Ring - Accessory Price History
Date Sold SKU Quality Control Price Image
20 Nov 2025 T18808 € 22,50 Nikon PK-11 Auto Extension Ring - Accessory Image
01 Oct 2024 T18727 € 22,50 Nikon PK-11 Auto Extension Ring - Accessory Image
25 Sep 2024 T49293 € 22,50 Nikon PK-11 Auto Extension Ring - Accessory Image
16 Sep 2024 T57955 € 15,00 Nikon PK-11 Auto Extension Ring - Accessory Image
29 Mar 2024 T23175 € 13,50 Nikon PK-11 Auto Extension Ring - Accessory Image
28 Mar 2024 T28254 € 13,50 Nikon PK-11 Auto Extension Ring - Accessory Image
04 Jun 2023 T42412 € 45,00 Nikon PK-11 Auto Extension Ring - Accessory Image