JML Optical 33360NR achromatic doublet lens

Product Description

Surplus Achromatic Doublet Lens – JML Optical P/N 33360NR – 2″ Diameter, 600mm Focal Length – Defense Lab Origin

This is a high-quality achromatic cemented doublet lens from JML Optical, part number 33360NR. Designed as a biconvex objective with one side nearly plano-convex and the other more curved, this lens features a long 600mm effective focal length (EFL) for precise imaging with minimal chromatic aberration. Sourced as surplus from a US Defense lab, it was custom-manufactured for demanding applications such as reconnaissance or optical sensing systems.

The lens combines a low-dispersion crown glass (N-BK7) with a high-dispersion flint glass for excellent color correction in the visible spectrum (400-700nm). In an achromatic doublet, the negative flint element and the positive crown element are shaped so that the dispersion of one cancels out the other, bringing two specific wavelengths (typically red and blue) to a common focus . This design also helps to reduce spherical aberration and coma, which are common in singlet lenses .

This is not a stock catalog item, making it a rare surplus find for optics enthusiasts, builders, restorers, or specialized projects.

Key Specifications

Applications & Common Uses

This lens’s unique combination of a large 2″ aperture and a long 600mm focal length makes it ideal for applications requiring high resolution at a distance.

• DIY Astronomical Refractor Telescope: An ideal objective lens for building a custom telescope. With a 600mm focal length, it will provide a range of 12x to 150x magnification using standard eyepieces. It is excellent for lunar, planetary, and deep-sky viewing with significantly reduced color fringing compared to a singlet lens.

• Spotting Scopes & Collimators: Suitable as a front objective for high-magnification terrestrial observation or as an optical component in a calibration collimator.

• Optical Experiments & Prototyping: A versatile tool for R&D breadboards, test benches, and educational setups requiring long-focal-length, aberration-controlled imaging .

• Defense & Professional Applications: In its original context, it could be used in surveillance systems, telephoto reconnaissance devices, hyperspectral imaging, or lab-based optical sensors. Its long focal length makes it great for magnified, distant observations while maintaining sharpness on-axis.

Condition

PRISTINE – EXCELLENT
OPTICAL SURFACES: Clean, no chips, digs, or coating issues. No delamination.
CLEAR APERTURE: Defect-free.
READY FOR IMMEDIATE INTEGRATION.

⚠ HANDLING NOTE: This is a precision optical component with two elements cemented together. Handle only by edges with clean gloves. Avoid shock, temperature extremes, and solvents that could damage the optical cement. Store in a clean, dry environment.