Category: February, 2010
Virtual Microscope: Cross section of the earth worm (Lumbricus terrestris)
The image above shows Lumbricus terrestris, the earth worm, in cross section. The red part in the center is the digestive system. You can zoom into the image. The only adjustment done to the image was a color correction. The image was not sharpened.
Human hair under the microscope
Today I’d like to show you a nice microscopic picture, which I took several years ago of two human hair. The pictures on the right show you the original, unprocessed image at the top, and a second cleaned-up image with a nice background on the bottom. The top image shows darkened corers from the field [...]
Köhler illumination to reduce reflections
The Köhler (or Koehler or Kohler) field diaphragm is located above the light source. It is responsible for controlling the width of the light beam (but not its intensity). The light source of a microscope without Köhler illumination will illuminate the whole specimen, which may be the source of stray light and excessive heating of [...]
5 Rules of buying a microscope
I’ve been repeatedly asked for advice concerning the purchase of microscopes of hobby and amateur purposes. The following rules should help you in your choice. Rule 1: Be weary about “department store” microscopes Enthusiasts who want to pick up the hobby frequently encounter their first microscopes in department stores and toy shops. If you are [...]
Magazine articles on microscopy
Popular Science magazine published many different articles dealing with microscopy. These articles can be accessed over Google Books: Popular Science articles on microscopy. Even though some of the articles are quite dated (going back into the 1930s), they still can contain valuable information and tips which remain valid up to today. Be aware that not [...]
How to make microscope filters
Commercial microscope filters are usually made of stained glass. In the case of patch stops (as used in dark-field illumination), they may be made of aluminum. The dark-field patch stops block some of the light and the specimen will appear bright on dark background. The traditional way of DIY patch stops is cutting them out [...]
Stereo microscope projects
You’ve bought your kid a stereo microscope as a birthday present and now wonder what to look at. Or maybe you are teacher and want to give your class an introduction into (stereo) microscopy and need some specimens to look at (or maybe you bought yourself one, and now want to start out observing…) Requirements [...]
Bacteria in phase contrast
The four pictures on the right show different bacterial species in phase contrast. About phase contrast Bacteria are transparent and therefore difficult to see using regular bright-field microscopy. The bacterial cells will appear just as bright as the surounding medium and there is no color contrast. Phase contrast optics provides a solution. Phase contrast optics [...]
Trichinella spiralis – the “pork worm”
Trichinella spiralis is the smallest nematode parasite in humans. It causes the disease trichinosis. It is also one of the most wide spread parasites of the world. It can be contracted by eating raw or half-cooked pork or wild game animals. Life Cycle of Trichinella spiralis T. spiralis larva are encapsuled in the muscle of [...]
Digital methods for improving microscopic photographs
Digital photography gives the users many new possibilities in improving photographs taken through the microscope. This post gives an overview of the different image processing functions that can be applied to microscopic images. This post places a focus on what is possible, but does not explain the “how” part. This is something that I plan [...]