9. Contrast methods for Leica DM4000 B/DM4500 P/DM5000 B

ence; rather, it provides only the difference over the entire wavelength or over a multiple of the wavelength. Entire wavelengths must be defined using a tilt compensator, a quartz wedge and by measuring the interference color. The results are more accurate than those obtained using a tilt compensator only.

Tilt compensator B with a measurement range of up to 5 orders based on Berek techniques Compensator (69.8) with an MgF2 plate for mea- suring up to approx. 5 orders of path differences in white or monochromatic light. You can read the path difference directly from the provided measurement table by calculating the sum of the two angles that are formed when the com- pensators are tilted simultaneously.

Tilt compensator K with a measurement range of up to 30 Orders (69.7)

For measuring path differences in white or monochromatic light up to the specified maxi- mum path difference. The compensator plate is made of calcite. The evaluation is created by performing simple calculations using the provid- ed tables and the specified measured constants. Measure in white or monochromatic light.

Using conoscopy for crystal structures

Birefringent crystals create interference imag- es, also called axis images or conoscopic imag- es (Fig. 71a,b), in the exit pupil of the objective (e.g. inside the objective). The form of these in- terference images and the changes that occur in these images when using a compensator make it possible to state how many axes the crystals have (uniaxial or biaxial crystals), how the axes are oriented, and whether or not the bi- refringence is positive or negative (positive or negative birefringent crystals).

Because the interference images appear in the eyepoint, they are not visible during typical observation (orthoscopy). An improvisational method for observing these images is to remove the eyepiece from the tube and to use a monoc- ular, held a few cm away, for looking into the tube. You can improve the observation by using a focusing telescope for the phase contrast.

However, additional crystals located in the field of view need to be masked out because they disrupt the interference images of a crystal located in the middle of the field of view.

Setting the conoscopy

For conoscopy, the specimen positions that are most suitable are those that have the lowest path differences (table Fig. 68).

Efficient conoscopic observation requires that the objective be centered precisely and that the cross position of the polarizers is exact.

•Rotate an objective with an aperture that is as high as possible (e.g. 40x, 50x or 63x) into the beam path.

•Rotate the condenser head into the beam path.

•Open the aperture diaphragm.

•Place the crystal being examined as close to the center of the field of vision as possible.

•Turn the 1.6x tube lens inward.

•Widen or narrow the iris diaphragm according to the size of crystal, and make the field dia- phragm narrower if necessary.

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Leica DM4500P, DM5000B manual Using conoscopy for crystal structures, Setting the conoscopy, Turn the 1.6x tube lens inward
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DM4500P, DM5000B, DM4000M specifications

The Leica DM4000M and DM4000B are state-of-the-art microscopes designed for professional use in the fields of biology, materials science, and clinical applications. Renowned for their precision and innovative features, these instruments are perfect for researchers and clinicians needing high-resolution imaging capabilities.

One of the standout features of both models is the advanced motorized focusing system, which allows for swift adjustments and precise control. This feature is particularly useful in time-sensitive research environments, where accuracy and speed are paramount. The ergonomically designed focus mechanism promotes user comfort during prolonged observation sessions.

Both the DM4000M and DM4000B incorporate the revolutionary Leica Application Suite (LAS) software. This intuitive platform is designed to maximize the functionality of the microscope, enabling users to capture, analyze, and share images seamlessly. The software’s integrated tools are perfect for documenting findings and enhancing research productivity.

Another notable characteristic of the DM4000 series is the modular design, which allows for easy customization and upgrading. This aspect ensures that users can tailor their microscopes to meet specific research needs, whether it be for fluorescence microscopy, phase contrast, or even special imaging techniques like HSR or IR.

The high-performance optics provide exceptional image contrast and clarity, allowing users to observe minute details in samples. The combination of high numerical aperture objectives and advanced optical coatings enhances the resolution, making the DM4000 series ideal for examining intricate biological specimens as well as materials with complex textures.

The DM4000B model is particularly suited for routine clinical applications, featuring specific tools designed for rapid diagnosis and efficient workflows. Its user-friendly interface and dedicated clinical applications streamline laboratory processes, making it an essential device in any clinical setting.

Additionally, both models are equipped with LED illumination, which offers consistent light intensity and color temperature. This feature improves sample clarity while reducing heat generation, thereby protecting sensitive specimens during prolonged observation periods.

In conclusion, the Leica DM4000M and DM4000B microscopes represent a blend of advanced technology, intuitive design, and high adaptability. Their user-focused features and exceptional optical performance make them indispensable tools for researchers and clinical professionals aiming for excellence in microscopy.
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