Olympus M.Zuiko digital ED 100-400mm 5.0-6.3 IS

The distance between the optical center of a lens and its image plane, expressed in millimetres. It can be a single value for fixed‑focal lenses or a range indicating the minimum and maximum focal lengths covered by zoom optics. This measurement helps users understand the field of view and zoom capability of cameras, lenses, and other optical devices.

The name of the mechanical or electronic interface that allows a camera lens to attach to its body, such as Canon EF, Nikon F, Sony E‑mount, Micro Four Thirds, etc. The value can be a single interface name or a comma‑separated list of multiple compatible mounts.

The classification of a camera lens, indicating its optical design and intended use such as prime, zoom, wide‑angle, telephoto, macro or specialty types (e.g., fisheye, polarizing). It helps buyers understand the lens’s focal range, aperture characteristics, and typical shooting scenarios.