MAGUS E10S Eyepiece

MAGUS E10S 10х/20mm Eyepiece with scale (D 23.2mm)
Magnification: 10x. Field of view: 20mm. Scale with 0.1mm division

The eyepiece with a scale is used for measuring the size of samples and their structures in linear units: millimeters or microns. The eyepiece is mounted instead of a standard 10x eyepiece. The scale is placed in the plane of the field diaphragm with a division of 0.1 mm. The eyepiece is compatible with microscopes with an eyepiece tube diameter of 23.2mm.

Setting up

Before measuring, the eyepiece with a scale must be calibrated for each objective that will be used. It requires a calibration slide – a stage micrometer with a scale. The minimum division is 0.01mm. The slide should be placed on the stage and the microscope should be focused on the scale. The eyepiece should be rotated in the eyepiece tube until the scales of a slide and an eyepiece are aligned parallel to each other.

Calculation of the eyepiece scale value for each objective

If you use low magnification objectives, you should calculate how many divisions of the eyepiece scale fit into the slide scale.
If you use medium and large magnification objectives, you should calculate how many divisions of the slide fit into the scale of the eyepiece.

Calculation for each objective is carried out according to the formula:
E=TL/A, where
E – the division of the eyepiece scale;
T – the division of the stage micrometer scale marked on the stage micrometer (0.01mm);
L – the number of divisions on the stage micrometer;
A – the number of divisions on the eyepiece scale.

The resulting values of the eyepiece scale division for each objective shall be recorded.

Calculating the true linear size of an object

When measuring an object, first you should count the number of divisions of the eyepiece scale that the object covers. The result is multiplied by the scale value previously calculated for the selected objective. The resulting value will be the true linear value of the object.
References and downloads


  • MAGUS Bio 230B Biological Microscope
  • MAGUS Bio 230BL Biological Microscope
  • MAGUS Bio 230T Biological Microscope
  • MAGUS Bio 230TL Biological Microscope
  • MAGUS Pol 850 Polarizing Microscope


Lens material: optical glass

Magnification, x: 10

Field of view diameter, mm: 20

Diopter adjustment:

Scale division, mm: 0.1

Eyepiece diameter, mm: 23.2

Body material: copper

Eye relief, mm: 10