Posts of the Category: Observations and pictures
Here I present some photomicrographic images that I made. All pictures are copyrighted and may not be used.
Dandelion pollen in dark-field
The pollen grains from a dandelion (Taraxacum sp.) were collected and air-mounted (no liquid mounting medium used). Eleven separate images were stacked together to increase the depth of field and to produce the final image. The color contrast was then adjusted. Dark-field patch stop was used.
Blood cells of a Frog and of a Human
The red blood cells of amphibians contain contain a nucleus, which is visible as a dark purple dot in the center of each cell. In contrast, the red blood cells of mammals do not possess a nucleus. The two pictures show both types of blood photographed with a 40x achromatic objective and a 2.5x photo [...]
Starch grains of a Potato
The pink oval structures are potato starch grains. One of the easiest and fastest way to observe starch grains is to scratch some sample off the surface of a potato with a sharp object and then adding some diluted iodine solution. Further Reading
Epidermis of a Tulip showing Stomates
Stomates (or stomas) are openings on the underside of a leaf, which allow gases to pass in and out of the leaf. The pictures show these stomates as narrow gaps. Two guard cells control the size of the opening. The guard cells have chloroplasts, which are visible as dark dots in the cell. During the [...]
Life in the Flower Pot Water (or: Comparing the Size of Prokaryotes and Eukaryotes)
Over the past few years, I’ve met several students who wanted to see bacteria through the microscopes that we have at school. Unfortunately, these devices are not equipped with phase contrast optics. The transparent bacteria are therefore difficult (but not impossible) to see. The biggest draw-back, however, comes from a different source: some of the [...]
How to make macro images
This time I’d like to talk about a topic which is only indirectly related to microscopy: macro imaging. Taking high-quality macro images can be quite a challenge and can involve quite a bit of trial and error until one has found the ideal conditions. The pictures of the rose have been taken with a Sigma [...]
Volvox
Volvox is a fresh water green algae and a member of the Chlorophyta. The picture shows a spherical volvox colony, each ball can contain hundreds, if not thousands of individual cells. The picture shows six daughter colonies inside the main colony. The main colony disintegrates and the daughter colonies are then released. Volvox is a [...]
Dandelion parachute ball up close
This is one of the first tries taking pictures with my new Sigma objective, and I have to admit that I’m very satisfied with the lens. The lens does not include image stabilization, a steady tripod is therefore a must. Contrast was slightly enhanced to make the background (my computer screen!) completely black. Mirror lock-up [...]