The specified photographic lens represents a manual focus prime lens manufactured by Nikon. The designation indicates a 50mm focal length and a wide maximum aperture of f/1.4, allowing for shallow depth of field and effective low-light performance. “AI” denotes the Aperture Indexing system, a mechanical linkage that communicates the lens’s aperture setting to the camera body for proper metering. This lens is a standard focal length option suitable for a wide range of photographic applications.
Its significance lies in its optical quality, fast aperture, and mechanical construction, making it a favored choice for photographers seeking a classic shooting experience. Historically, this type of lens provided a cost-effective and high-performing option. The fast f/1.4 aperture offers distinct advantages, including enhanced control over depth of field, enabling subjects to be isolated against blurred backgrounds and facilitating photography in dimly lit environments without resorting to higher ISO settings.