Nikon Nikkor 300mm F4.5 Ai

Nikkor 300mm f/4.5 AI

• Lens Mount: Nikon F Mount (AI - Aperture Indexing)

• Production Period: 1977 – 1978 (ซีเรียลนัมเบอร์: 480001 – 520286)

• Format Coverage: 35mm Full-Frame (FX)

• Focal Length: 300mm (เทียบเท่า 450mm บนกล้องนิคอนเซนเซอร์ DX / APS-C)

• Maximum Aperture: f/4.5

• Minimum Aperture: f/32

• Optical Construction: 6 Elements in 5 Groups (โครงสร้างเลนส์ดั้งเดิม Classic optical layout)

• Angle of View: 8° 10' (บนกล้อง Full-Frame)

• Minimum Focus Distance: 4.0 m (13 ft)

• Focusing System: Manual Focus (เฮลิคอยด์หมุนนุ่มนวล ระยะหมุนโฟกัสยาวช่วยให้หมุนได้แม่นยำ)

• Diaphragm Blades: 6 Blades

• Filter Size: 72 mm (Screw-in filter)

• Built-in Features:

  • Built-in Telescopic Hood: ฮู้ดโลหะสไลด์ดึงออก/เก็บได้ในตัว

  • Rotating Tripod Collar: คอลลาร์ยึดขาตั้งกล้องแบบหมุนได้ 360 องศา ปรับแนวตั้ง-แนวนอนได้สะดวก (ถอดแยกไม่ได้)

• Dimensions: Approx. 78.5 × 200 mm

• Weight: Approx. 1,100 g (1.1 kg)

Description

The Nikkor 300mm f/4.5 AI is a classic manual-focus telephoto prime lens introduced by Nikon in 1977. Serving as a refined update to the earlier non-AI 300mm variants, this lens implemented Nikon’s factory Automatic Maximum Aperture Indexing (AI) system, allowing seamless exposure metering with AI-compatible film SLRs, modern DSLRs, and mirrorless bodies via FTZ adapters.

Built like a tank, the lens features an all-metal barrel, a tactile diamond-patterned rubber focus ring with a long focus throw for precise adjustments, an integrated built-in telescopic lens hood, and a 360-degree rotating tripod collar. Its optical construction consists of 6 elements in 5 groups, delivering sharp central resolution, contrast-rich color rendition, and impressive background compression when stopped down to f/5.6 or f/8.

With a maximum aperture of f/4.5, a minimum focus distance of 4.0 meters, and a standard 72mm filter thread, the Nikkor 300mm f/4.5 AI remains a durable, accessible, and high-performing vintage telephoto tool for collectors, film enthusiasts, and nature/landscape photographers seeking classic manual telephoto optics.