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Case Study: Transforming Microscopy with the 50X Objective Lens

Case Study: Transforming Microscopy with the 50X Objective Lens

Delving into the realm of cutting-edge microscopy, the 50X long working distance objective lens emerges as a game-changer, offering unparalleled magnification for precise visualization in biomedical research and precision testing scenarios. Crafted with an infinite conjugate design, it seamlessly integrates into various microscopy setups. Tailored for near ultraviolet (NUV) wavelengths, particularly at 355nm, it achieves remarkable transmittance and superior achromatic correction. Boasting a numerical aperture (NA) of 0.65 and a generous 10mm working distance, it excels in industrial applications, ensuring exceptional performance across the field of view.


Project Overview

At the forefront of microscopy innovation lies the 50X infinite conjugated long working distance microscope objective lens, a versatile tool catering to a spectrum of disciplines including biomedical research, precision testing, and material analysis. Its unrivaled magnification capabilities enable crystal-clear visualization and high-resolution examination of minuscule biological and material structures. Designed to meet the diverse demands of modern science, this objective lens offers precise observation capabilities across various domains. Its infinite conjugate design enhances adaptability, seamlessly integrating with different microscopy systems and accessories to address diverse experimental needs. Serving professionals in biology, medicine, and materials science, this dynamic tool propels scientific research and technological advancements forward.



  • Focal Length: 4mm
  • Numerical Aperture (NA): 0.65</span
  • Wavelength: 355-532nm
  • Field of View (FOV): Φ0.48mm
  • Working Distance: 10mm


Design Structure

Crafted with precision, the 50X microscope objective lens is engineered to correct for the NUV (Near Ultraviolet) band, catering to the requirements of near-ultraviolet lasers. Its NA of 0.65 facilitates an extended working distance of 10mm, providing flexibility for industrial processing applications. Achieving such a long working distance necessitates a meticulous design strategy, involving the manipulation of light angles through the front and back lens sets. Micro objectives with high NA and extended working distances often rely on specialized glass, resulting in a sophisticated structure compared to conventional microscope objectives.

Performance Evaluation

The evaluation of microscopic objective performance hinges on accurate measurements of dispersion spot radius and modulation transfer function (MTF). In this model, the RMS radius of the dispersion spot is finely tuned to 0.205μm (on the axis), 0.251μm (at 0.7 field of view), and 0.333μm (at 1 field of view). The MTF on the axis meets 2000 lp/mm, reaching the diffraction limit. Despite minor deviations off the axis due to minimal astigmatism and chromatic aberration, the MTF still achieves 1500 lp/mm, approaching the diffraction limit. With a single-point light source, the entire field of view meets the diffraction limit, ensuring exceptional imaging consistency.

Spot Diagram

MTF Measurement


Special Features

A standout feature of this lens is its proficiency in handling the 355nm wavelength in the NUV band. Calibration in the NUV band poses challenges due to limited material options, yet this design conquers the task, achieving 50% transmittance and impeccable achromatic correction. Compatible with eyepieces featuring a 24mm field number and a 0.48mm object field of view, this lens ensures consistent clarity across the entire field of view, meeting the stringent flat field requirements for microscopic objectives.

Field curvature and distortion


Longitudinal aberration



Meticulously engineered to deliver superior performance, the 50X microscope objective lens boasts an elevated numerical aperture (NA) and an expansive field of view, complemented by an extended 10mm working distance. Operating within the wavelength range of 355-532nm, it spans the near-ultraviolet band, making it ideal for precision laser processing at 355nm and 532nm. Additionally, it showcases remarkable imaging capabilities at 365nm and 405nm. As an epitome of high-end specialized objectives, this lens caters to the demands of specific and rigorous applications, marking a significant milestone in microscopy advancement.

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