Stereo Microscopy Applications and Illumination

Advantages of LED Illumination

Stereo Microscopes use two separate optical beam paths - mutually inclined at aprox. 15 ° -  to look at three-dimensional microstructures. Since the invention by Horatio S. Greenough Stereo Microscopes are based on foundations described by Ernst Abbe. The newly developed optical glass by Otto Schott helped from the beginning to perfect them.

Today, more than a century later Stereo Microscopes are widely used for life an material science tasks as well as for  clinical routine industrial inspection tasks. Always illumination is the key to contrast the surface of the specimen and therefore to allow an informative investigation and optical documentation. The better the object is illuminated, the more details become visible.

For more than 50 years SCHOTT lighting and imaging provides innovative illumination solutions for Stereo Microscopes in the same aspiration as the company founder Otto Schott did before. For us therefore illumination is not just an accessory but our passion to enable customers globally to do their tasks better day by day.


In general brightfield, darkfield and polarization contrast can be used to optically contrast and visualize respective features on the surface of the specimen.

All brightfield methods are widely used for at various applications.
Our incident brightfield ringlights from the EasyLED and VisiLED series for example, provide a very bright and homogeneous illumination. Their advantage is that individual segments can be quickly and variably controlled, so that the active segment is rotated around the specimen being illuminated. This means the test object no longer has to be manually turned to provide illumination from different directions. For example, this can considerably simplify or speed up quality control in industrial manufacturing.
Face of coin illuminated from different directions
by segmented LED groups in a VisiLED ringlight

For low working distance objectives, and for higher contrast purposes, gooseneck fibre light guides or flexible light guides containing Puravis® lead free fibers in combination with a cold light source from the KL series are recommended. They can be adjusted at different angles to the specimen to deliver a variety of contrasts. As SCHOTT offers both advance cold light sources with LED light engines as well as a professional true color halogen light the user has the ultimate possibilities with regard to all possible illumination techniques
Comparison of brightness of luminous spot

Left: VisiLED S80-55 ringlight (with 80 LEDs), working distance 75 mm

Right: Gooseneck, Ø 5 mm, KL 1600 LED light source

Brightfield transmitted light from the bottom is used for all kinds of transparent
Specimens. Our transmitted light stages from the EasyLED and VisiLED series for example, provide a very bright and homogeneous illumination and a unique Scratch resistant SCHOTT
Opalika® surface.

The darkfield method is an illumination technique from the side. Here no light will be reflected through the objective and therefore this method can be used for virtually transparent and colorless objectives.

In addition to these general set ups linear polarized light by an polarizing and analyzing filter within the beam path can be very efficiently used in Stereo Microscopy to contrast e.g. some inner structure of material or to identify metal particles within others.

Conclusion
Stereo Microscopy is workhorse of quality departments and laboratories and careful assessment of the lighting requirement is a key element of professional results. SCHOTT is able to offer the full range of fiber optic and LED lighting products with an extensive range of accessories to meet all customer’s needs.

 

News, Exhibitions & Events
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April
Exhibition Aircraft Interiors Expo, Hamburg, Germany, 04-04 to 04-06-2017
21.
March
Exhibition IDS 2017, Cologne, Germany, 03-21 to 03-25-2017