Life Science Solutions
Application Notes

Optimizing Your Oblique Observation Using Our Flexible Contrast Solution

Contrast Optimization When Using Stereo Microscopes

Optical microscopes are typically adjusted for Köhler illumination, which helps ensure even illumination of samples. However, it is difficult to apply Köhler illumination to stereo microscopes because of the stereoscopic viewing, low magnification, zoom functionality, and the wide variety of samples. Instead, oblique illumination is used with stereo microscopes as an optimized illumination method.

Challenges of the Oblique Illumination Technique

When oblique illumination is used, the observation image is affected by the (1) shadow strength (contrast level) and (2) the angle and size of the shadow. However, conventional oblique mechanisms do not allow independent adjustment of the shadow strength and the angle and
size of the shadow while maintaining even illumination for all magnifications.

Olympus’ Solution Using a LED Transmitted Light Illumination Base with Flexible Contrast Functionality

To solve this issue, Olympus developed new a contrast method using the SZX2-ILLTQ quad position LED transmitted light illumination base. This new LED illumination base enables you to optimize your observation by adjusting the contrast level and the angle and size
of the light/shadow (oblique) independently.

The solution involves a simple two step procedure:

First, you can choose between three cartridges to set the contrast level (low/standard/high). The vertical columns in Figure 1 show that the contrast increases (bottom to top) depending on the selected cartridge: COBL→COB→COBH.

Second, you can also change the angle and size of the light/shadow with 5 levels by changing oblique scales on the cartridge. The horizontal images in Figure 1 (left to right) show how this adjustment changes the light/shadow position in accordance with the oblique scale selection.

Cartridge and oblique scale selection

Figure 1: How the view changes depend on the difference of cartridge and oblique scale selection.


As demonstrated, the Olympus SZX2-ILLTQ quad position LED illumination base enables fine contrast adjustments, which can help make your oblique observation using a stereo microscope more flexible and efficient.

Olympus SZX2-ILLTQ

Products related to this application

Research Stereomicroscope System


  • Versatile Model
  • Wide Zoom Ratio (10:1) and Natural View
  • Simple Fluorescence Observation
Research Stereomicroscope System


  • Advanced Model
  • Ultra-Wide Zoom Ratio (16.4:1) and High-Resolution
  • Advanced Fluorescence Observation

was successfully added to your bookmarks

View BookmarksClose

Maximum Compare Limit of 5 Items

Please adjust your selection to be no more than 5 items to compare at once

Sorry, this page is not
available in your country.