MAGUS 20PLL Objective

MAGUS 20PLL 20х/0.40 Plan L WD 8.80mm Objective
Infinity-corrected plan achromatic objective. Magnification: 20x. Aperture: 0.40

The resolution limit of the 20х/0.40 objective is 0.69µm.
Chromatic aberrations are corrected for blue and red light, spherical aberration for green light, and field curvature corrected to 90% of the field of view diameter.

The objective is infinity-corrected. The parfocal distance is 45mm. When working with a 10x/22mm eyepiece, the field of view diameter will be 1.1mm. Designed to work with samples without a cover glass.

The 20x metallurgical objective has a long working distance of 8.8mm. Working distance is the distance from the front lens of the objective to the object under study, at which the image of the object is in focus. Objects of study may have a pronounced topography, e.g., samples of printed circuit boards with different levels of electronic components and semiconductors. A large working distance prevents accidental damage to the front lens of the objective or sample when focusing and when turning the revolver to change objectives.

The lower limit of useful microscope magnification when working with a 20х objective is 200x. A lower magnification will not allow you to distinguish the details of the object in the image produced by the objective.
The upper limit of useful magnification when working with the 20х objective is 400x. Higher magnification is considered "useless" because it does not provide new detail in the image of the object.
With a 20x/0.40 objective, use eyepieces with magnifications from 10x to 20x.

Plan achromatic objectives produce an image equally focused in both the center and at the edges with minimal distortion. This feature is used for taking digital images and for working in conjunction with wide-field eyepieces with a 22mm field of view.
References and downloads


  • MAGUS Metal 600 Metallurgical Microscope
  • MAGUS Metal 630 Metallurgical Microscope
  • MAGUS Metal 650 Metallurgical Microscope
  • MAGUS Metal V700 Metallurgical Inverted Microscope


Lens material: optical glass

Objective class by aberration correction degree: plan achromatic

Tube length: infinity-corrected (∞)

Contrast technique: brightfield

Magnification, x: 20

Aperture: 0.40

Working distance, mm: 8.80

Parfocal distance, mm: 45

Cover glass thickness, mm: without cover glass

Spring-loaded frame:


Body material: copper