Leica HI PLAN Achromatic Objective Lens

Overview

The Leica HI PLAN Achromatic Objective Lens is a high-performance, parfocal, and parcentric optical component engineered for routine transmitted-light microscopy in the visible spectrum (400–700 nm). Based on classical achromatic doublet design principles, it corrects chromatic aberration for two primary wavelengths—typically 486 nm (blue/F-line) and 656 nm (red/C-line)—and spherical aberration for one wavelength (usually 546 nm, the e-line). This correction yields a focal shift between red and blue channels of ≤2× the objective’s depth of field—enabling reliable multi-wavelength qualitative imaging without significant refocusing. With an optical field number (OFN) of up to 25 mm, the HI PLAN series delivers exceptional flatness across the entire field of view, minimizing edge distortion and ensuring sharp, consistent resolution from center to periphery. Designed for integration into Leica DM series upright and inverted research microscopes, these objectives comply with standard RMS (Royal Microscopical Society) thread specifications (M25×0.75) and are optimized for use with 160 mm mechanical tube length or infinity-corrected optical paths when paired with appropriate tube lenses.

Key Features

• Optimized achromatic correction for F- and C-lines, minimizing axial color fringing in brightfield and phase contrast applications
• Field flatness (PF) rated up to 25 mm OFN—ensuring sharp focus across the full visual field without peripheral softening
• Parfocal and parcentric alignment compatible with Leica’s modular microscope platforms (e.g., DMi8, DM6 B)
• Available in multiple magnifications (e.g., 5×, 10×, 20×, 40×, 63×) with standardized numerical apertures (NA) and working distances (WD) appropriate for each class
• HI PLAN PH variants support phase contrast microscopy with matched annuli and phase plates; HI PLAN DIC versions incorporate strain-free optics for polarized light compatibility
• Multi-layer anti-reflection coatings enhance transmission efficiency (>95% average in visible range), reducing internal reflections and improving signal-to-noise ratio

Sample Compatibility & Compliance

The HI PLAN Achromatic Objective is suitable for fixed and live biological specimens mounted in aqueous media, glycerol, or immersion oil (for oil-immersion variants). It supports standard glass coverslip thicknesses (No. 1.5, 0.17 mm) and accommodates typical sample heights encountered in histology, cytology, and routine pathology workflows. Objectives conform to ISO 8578:2017 (Microscopes — Mechanical tube length and infinity-corrected optical systems) and adhere to DIN/ISO standards for labeling, marking, and mechanical interface tolerances. While not designed for GMP-regulated environments requiring full 21 CFR Part 11 audit trails, the objective’s optical stability and repeatability support GLP-aligned documentation protocols when integrated into validated microscope systems.

Software & Data Management

When used with Leica Application Suite X (LAS X) software, the HI PLAN objective is auto-recognized via encoded turret communication (where supported), enabling automatic magnification scaling, calibration persistence, and metadata embedding (e.g., objective ID, NA, WD, correction type) into acquired image files (TIFF, LIF). LAS X supports quantitative intensity profiling across the FOV to verify field flatness performance, and its multi-channel registration tools accommodate the known chromatic offset inherent to achromats—facilitating accurate overlay of DAPI/FITC/TRITC channels in widefield fluorescence workflows. Objective-specific calibration profiles can be archived and recalled per user or experiment, supporting traceable imaging workflows compliant with internal SOPs.

Applications

• Routine brightfield examination of stained tissue sections (H&E, Masson’s trichrome)
• Phase contrast imaging of unstained live cells (e.g., fibroblasts, epithelial monolayers)
• Differential interference contrast (DIC) of transparent subcellular structures in fixed preparations
• Educational microscopy labs requiring cost-effective, robust, and interchangeable objectives
• Quality control inspection in materials science (e.g., polymer film homogeneity, coating uniformity)
• Preliminary screening prior to high-resolution imaging with apochromatic or specialized objectives

FAQ

What is the difference between HI PLAN and standard achromatic objectives?
HI PLAN objectives feature enhanced field flatness (up to 25 mm OFN) and tighter manufacturing tolerances for parfocality and chromatic correction compared to basic achromats—making them suitable for digital imaging and multi-user lab environments.
Can HI PLAN objectives be used for fluorescence imaging?
Yes—especially FL PLAN variants—but standard HI PLAN objectives provide adequate transmission for routine widefield fluorescence (e.g., FITC, TRITC); however, they lack the extended correction and anti-fluorescence-quenching coatings of dedicated fluorite or apochromat designs.
Are HI PLAN objectives compatible with third-party microscopes?
Mechanically, yes—if the microscope uses RMS-threaded nosepieces and supports the specified tube length or infinity-correction configuration; however, full electronic encoding and LAS X integration require Leica hardware interfaces.
Do HI PLAN objectives support Köhler illumination alignment?
Yes—they are fully compatible with standard Köhler setup procedures, including field diaphragm centering and condenser aperture optimization for optimal contrast and resolution.
What maintenance is recommended for long-term optical performance?
Regular cleaning using lens-grade solvent (e.g., reagent-grade ethanol or acetone) and optical-grade cotton swabs; avoid ultrasonic cleaning or abrasive wipes. Store in low-humidity, dust-free environments with protective caps installed.