Posts of the Category: Techniques
Here I explain the handling of the microscope and different methods to enhance contrast.
Here I would like to show you two images of potato starch grains taken with different optical contrasting methods.
Drawing is still a useful method for documenting microscopic specimens, despite advances in (digital) imaging technologies. There are certain advantages in drawings that photographs do not possess.
There are a range of different possibilities: Enhancing contrast: Photo editing software (such as Adobe Photoshop or GIMP) contain functions that enhance the contrast of an image. Find the menu point “Auto Levels” or simply “Levels”. This tool will make the darkest part of the image black (even if it was not black before) and [...]
Oblique illumination is a contrast enhancing technique which can be realized with the use of home-made filters (patch stops) placed into the filter holder of the microscope condenser.
Darkfield microscopy is one of the simplest and cheapest contrast enhancing techniques. It works well for specimens that have a refractive index which is different from its surrounding medium, but which are difficult to see because they lack color. Dark field microscopy shows the specimen bright on a dark background.
The condenser aperture diaphragm (or iris diaphragm) is used to control the contrast and resolution of an image. This article explains the usage of the diaphragm.
Koehler illumination ensures that the specimen receives a bright uniform light. Only those areas actually seen are illuminated.
It is not necessary to purchase a dedicated polarizing microscope to observe specimens in polarized light. A pair of linear polarizing filters is enough.