The AF-I Nikkor ED 400mm f/2.8 D IF is an autofocus lens produced by Nikon. The lens features a new coreless integrated drive motor for fast autofocus. It also features a M/A switch for quick switching between autofocus and manual focus.
This manual describes the AF‑I Nikkor ED 400mm f/2.8 D IF lens, its internal focusing (IF) system, and the core‑less autofocus mechanism that delivers rapid and quiet focusing. It also explains the instant switch between autofocus and manual focus via the M/A ring and the transmission of distance information to compatible Nikon camera bodies.
The document includes depth‑of‑field tables, macro close‑up ring data, and legal copyright information. It is intended for photographers using Nikon F‑series SLRs such as the F4, F90X, F90, and F70, providing guidance on proper handling, focusing, and accessory use. This manual is written in Chinese.
| Focal length | 400 mm |
|---|---|
| Maximum aperture | f/2.8 |
| Focus type | Internal focusing (IF) |
| Autofocus mechanism | Coreless focus‑driving mechanism |
| Focus mode switch | Manual via M/A ring |
| Distance information transmission | Supported |
It delivers rapid and quiet autofocus, dramatically reducing focusing time.