An optical microscope is often one of the central devices in a life-science research lab. It can be used for various applications which shed light on many scientific questions. Thereby the…

For most microscope applications, there are generally only two sets of optics which are adjusted by the user, namely, the objectives and the eyepieces. Of course, this is assuming that the microscope…

The technique of Koehler Illumination is one of the most important and fundamental techniques in achieving optimum imaging in any given light microscope set-up. Although it should be routinely used as…

To examine specimens at high magnifications using the microscope, there are a number of factors which need to be taken into consideration. These include resolution, numerical aperture (NA), the…

Numerical aperture (abbreviated as ‘NA’) is an important consideration when trying to distinguish detail in a specimen viewed down the microscope. NA is a number without units and is related to the…

Optical microscopes are used to magnify objects which are otherwise invisible for the human eye. For this purpose high quality optics is necessary to achieve appropriate resolution. However, besides…

This lecture describes the famous experiments of Ernst Abbe which showed how diffraction of light by a specimen (and interference with the illuminating light) gives rise to an image and how collection…

In microscopy, the term ‘resolution’ is used to describe the ability of a microscope to distinguish detail. In other words, this is the minimum distance at which two distinct points of a specimen can…

“Infinity Optics” refers to the concept of a beam path with parallel rays between the objective and the tube lens of a microscope. Flat optical components can be brought into this “Infinity Space”…

How to break a fundamental law of physics and win a Nobel Prize to boot. Stefan Hell explains super-resolved fluorescence microscopy for which he shared the 2014 Nobel Prize in chemistry.

The history of microscopy begins in the Middle Ages. As far back as the 11th century, plano-convex lenses made of polished beryl were used in the Arab world as reading stones to magnify manuscripts.…

Joseph Gall takes us through the history of early microscopes and the discovery of the cell. Compound microscopes were invented alongside the telescope in the 17th century; however these microscopes…

Light has properties of particles and waves. Understanding the wave nature of light is essential to understanding the workings of a microscope. This lecture describes Huygens Wavelets,…