The document is an instruction manual that provides information on the product's features and instructions on how to use it.
This manual covers everything needed to use the Nikon SB-21 speedlight, including safety notes, battery installation, attaching the controller, camera shutter settings, TTL and manual flash modes, guide numbers, focus illumination, and external power options. It also contains detailed specifications and guidance for determining aperture based on shooting distance.
Additional sections describe accessories, care tips, and troubleshooting. The document is organized with a clear table of contents and includes diagrams and tables for quick reference.
| Power source | Four 1.5 V AA alkaline, zinc‑carbon or NiCd batteries |
|---|---|
| Maximum flashes (alkaline) | 200 flashes, 8 sec recycle |
The SB-21 can fire up to 200 flashes with alkaline‑manganese AA batteries, with a recycling time of about 8 seconds.
The SB-21 can be powered by the optional AC Unit LA‑2 or the DC Unit LD‑2.