Nikon PK-11 Auto Extension Ring - Accessory

Skip to product information
1 of 1

Model Details

The PK-11A is an 8mm Auto Extension Tube. Extension tubes enable a lens to focus closer than its normal set minimum focusing distance, placed between the lens and camera body. Use one or multiple extension tubes together. An AI Nikkor lens will retain automatic diaphragm and meter coupling functions, letting you compose, focus and meter at a wide-open apertures. The tubes can also be used for manual exposure control.

  • Size: 66 x 16mm.
  • Weight: 51g.
View full details

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.

1 of 5
Nikon PK-11 Auto Extension Ring - Accessory Price History
Date Sold SKU Quality Control Price Image