A. Jaegers Achromatic Cemented Doublet Telescope Objective

Authentic vintage achromatic objective lens from A. Jaegers – the iconic supplier that powered generations of amateur telescope makers! This matched cemented doublet features classic edge markings confirming its heritage: Radius of curvature marked 50-inch on multiple surfaces, “Jaeger’s” identifier and 876 mm fl” focal length.

Perfect for building or upgrading a classic 3.2-inch refractor with outstanding performance for its era.

Key Specifications:

• Aperture: 82 mm (full diameter, Clear 78 mm)

• Focal Length: 876 mm (≈34.5 inches)

• f/ratio: ≈ f/10.7 – long focus for superior color correction

• Center Thickness: ~15mm

• Edge Thicknesses: Crown ≈8 mm, Flint ≈4.5 mm

• Design: Cemented achromatic doublet (biconvex BK7-equivalent crown + meniscus F2-equivalent flint) for color correction across visual spectrum

• Coating: Uncoated (authentic vintage – high transmission with classic reflectivity)

• Condition: Excellent clean surplus – two small nicks outside of central clear aperture of 78 mm; pristine surfaces

This long-focus design delivers sharp, high-contrast views with minimal false color – ideal for Moon, planets, and double stars. A true piece of astronomical history from Al Jaegers’ legendary catalogs.

Applications & Performance:

• Build a premium visual refractor for planetary/lunar observing

• High-magnification detail on Jupiter, Saturn rings, lunar craters

• Rich-field sweeping or brighter deep-sky objects

• Educational optics projects or vintage scope restoration