Leica Science Lab - Tag : Optics https://www.leica-microsystems.com//science-lab/tag/optics/ Article tagged with Optics en-US https://www.leica-microsystems.com/19036 Basics in Microscopy Live-Cell Imaging Fluorescence Microscopy Widefield Microscopy Factors to Consider When Selecting a Research Microscope 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 configuration and features of the microscope are crucial for its application coverage, ranging from brightfield through fluorescence microscopy to live-cell imaging. This article provides a brief overview of the relevant microscope features and wraps up the key questions one should consider when selecting a research microscope. https://www.leica-microsystems.com/science-lab/factors-to-consider-when-selecting-a-research-microscope/ Thu, 24 Sep 2020 10:10:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/19684 Basics in Microscopy Eyepieces, Objectives and Optical Aberrations 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 is already corrected for Koehler Illumination during which the condenser and diaphragms are adjusted. https://www.leica-microsystems.com/science-lab/eyepieces-objectives-and-optical-aberrations/ Mon, 28 Aug 2017 07:36:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/19639 Basics in Microscopy Koehler Illumination: A Brief History and a Practical Set Up in Five Easy Steps 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 part of setting up a microscope, many microscopists are put off by thinking that the correct set-up is complex and time consuming and it is therefore still not widely practised. By getting to know the two main components of the microscope which are adjusted in this technique (the diaphragms and sub-stage condenser) in reality, correct set-up should only take a matter of minutes. A correctly aligned microscope can result in greatly improved images of uniform contrast and illumination as well as higher resolution and more detail. In this article, we will look at the history of the technique in addition to how to adjust the components in five easy steps. https://www.leica-microsystems.com/science-lab/koehler-illumination-a-brief-history-and-a-practical-set-up-in-five-easy-steps/ Thu, 17 Aug 2017 07:07:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/19673 Basics in Microscopy Immersion Objectives: Using Oil, Glycerol, or Water to Overcome some of the Limits of Resolution 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 working distance of objectives and the refractive index of the medium through which the image is collected by the front lens of an objective. In this article, we will briefly look at how using an immersion medium between the coverslip and the objective front lens helps to increase the NA and resolution. https://www.leica-microsystems.com/science-lab/immersion-objectives-using-oil-glycerol-or-water-to-overcome-some-of-the-limits-of-resolution/ Wed, 09 Aug 2017 12:07:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/19605 Basics in Microscopy Collecting Light: The Importance of Numerical Aperture in Microscopy 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 angles of light which are collected by a lens. In calculating NA (see below), the refractive index of a medium is also taken into account and by matching the refractive index of a slide or cell culture container with an immersion medium, then more of the detail of a specimen will be resolved. The way in which light behaves when travelling from one medium to another is also related to NA (and termed ‘refraction’). This article also covers a brief history of refraction and how this concept is a limiting factor in achieving high NA. https://www.leica-microsystems.com/science-lab/collecting-light-the-importance-of-numerical-aperture-in-microscopy/ Wed, 12 Jul 2017 07:46:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/19234 Basics in Microscopy Optimization of the Interplay of Optical Components for Aberration free Microscopy 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 intentional effects, all optical components have also unwanted intrinsic influence on light, resulting in aberrations. This article highlights optical elements and their physical parameters involved in this process. Based on this, it gives a historical overview of philosophies about how to cope with aberration reduction. Seeing the microscope as a whole system turned out to be beneficial, leading to the harmonization of its constituents for optimal microscopic results. https://www.leica-microsystems.com/science-lab/optimization-of-the-interplay-of-optical-components-for-aberration-free-microscopy/ Wed, 31 May 2017 08:58:00 +0000 Karl-Heinz Schade, Peter Euteneuer, Dipl. Phys. Arnold Müller-Rentz https://www.leica-microsystems.com/15098 Basics in Microscopy Video Talk by Kurt Thorn: The Abbe Diffraction Experiment 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 of diffracted light defines the resolution of the microscope. These concepts are demonstrated by using a diffraction grating as a specimen and visualizing and comparing the diffraction pattern in the back focal plane as well as the image in the image plane. https://www.leica-microsystems.com/science-lab/video-talk-by-kurt-thorn-the-abbe-diffraction-experiment/ Mon, 13 Feb 2017 12:12:00 +0000 PhD Kurt Thorn https://www.leica-microsystems.com/18991 Basics in Microscopy Microscope Resolution: Concepts, Factors and Calculation 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 still be seen - either by the observer or the microscope camera - as separate entities. The resolution of a microscope is intrinsically linked to the numerical aperture (NA) of the optical components as well as the wavelength of light which is used to examine a specimen. In addition, we have to consider the limit of diffraction which was first described in 1873 by Ernst Abbe. This article covers some of the history behind these concepts as well as explaining each using relatively simple terminology. https://www.leica-microsystems.com/science-lab/microscope-resolution-concepts-factors-and-calculation/ Fri, 02 Dec 2016 14:09:00 +0000 PhD Martin Wilson https://www.leica-microsystems.com/17636 Widefield Microscopy Basics in Microscopy Infinity Optical Systems “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” without influencing image formation, which is critical for the utilization of contrast methods such as DIC or fluorescence. Modern microscopy techniques require the addition of multiple optical instruments, such as light sources or laser devices, into the infinite light path. Different approaches to fulfill this need have emerged and are described here. https://www.leica-microsystems.com/science-lab/infinity-optical-systems/ Fri, 11 Mar 2016 16:28:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/16796 Super-Resolution Video: Fluorescence is a State of Mind 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. https://www.leica-microsystems.com/science-lab/video-fluorescence-is-a-state-of-mind/ Thu, 07 Jan 2016 20:45:00 +0000 Prof. Dr. Dr. h.c. Stefan Hell https://www.leica-microsystems.com/16800 Stereo Microscopy What do you Call a Drosophila who Likes to Drink? A Bar Fly! The thought of a Drosophoila headed to the local bar for a drink creates a funny joke, but after long hours of sorting flies under a microscope that causes eyestrain or neck pain, you may be the one that wants to head to the local bar for a drink! Unfortunately most users do not know why they experience discomfort when using a stereo microscope. https://www.leica-microsystems.com/science-lab/what-do-you-call-a-drosophila-who-likes-to-drink-a-bar-fly/ Wed, 21 Oct 2015 16:22:00 +0000 Mike Tjepkema https://www.leica-microsystems.com/16124 Basics in Microscopy A Brief History of Light Microscopy – From the Medieval Reading Stone to Super-Resolution 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. However, the further development of these lenses into the first microscopes cannot be attributed to any one person. It took the ideas and designs of many scientists and scholars to produce instruments capable of strong magnification. https://www.leica-microsystems.com/science-lab/a-brief-history-of-light-microscopy-from-the-medieval-reading-stone-to-super-resolution/ Tue, 08 Sep 2015 17:41:00 +0000 Wymke Ockenga https://www.leica-microsystems.com/14400 Basics in Microscopy Video Talk by Joseph Gall: Early History of Microscopy 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 were not widely used until the late 19th century due to optical aberrations. In the meantime, simple microscopes were used throughout the 1700s and 1800s to make major discoveries in biology, including the first descriptions of the nucleus, cilia, cells, bacteria, and protozoans. Once optics improved in the mid to late 1800s, compound microscopes were used to discover chromosomes, mitosis, and other cellular structures. https://www.leica-microsystems.com/science-lab/video-talk-by-joseph-gall-early-history-of-microscopy/ Tue, 11 Aug 2015 07:48:00 +0000 BS, PhD Joseph Gall https://www.leica-microsystems.com/15511 Super-Resolution Encoding and Decoding Spatio-Temporal Information for Super-Resolution Microscopy The challenge of increasing the spatial resolution of an optical microscope beyond the diffraction limit can be reduced to a spectroscopy task by proper manipulation of the molecular states. The nanoscale spatial distribution of the molecules inside the detection volume of a scanning microscope can be encoded within the fluorescence dynamics and decoded by resolving the signal into its dynamics components. https://www.leica-microsystems.com/science-lab/encoding-and-decoding-spatio-temporal-information-for-super-resolution-microscopy/ Fri, 17 Apr 2015 10:35:00 +0000 https://www.leica-microsystems.com/13927 Basics in Microscopy Video Talk by Jeff Lichtman: Point Spread Function An infinitesimally small point appears in the microscope as a spot with a certain size, blurred in the z-direction and with concentric rings around it. This "point spread function" reveals many of the optical properties of your microscope. This lecture explains why and how the microscope images a point as a point spread function. https://www.leica-microsystems.com/science-lab/video-talk-by-jeff-lichtman-point-spread-function/ Thu, 08 Jan 2015 13:23:00 +0000 Dr. Jeff Lichtman https://www.leica-microsystems.com/11763 Basics in Microscopy Video Talk by Jeff Lichtman: Resolution in Microscopy – Wave Optics and the Diffraction Limit 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, constructive/destructive interference, and diffraction. https://www.leica-microsystems.com/science-lab/video-talk-by-jeff-lichtman-resolution-in-microscopy-wave-optics-and-the-diffraction-limit/ Thu, 14 Aug 2014 12:48:00 +0000 Dr. Jeff Lichtman https://www.leica-microsystems.com/15675 Light Sheet Microscopy Light Sheet Fluorescence Microscopy: Beyond the Flatlands Light Sheet Fluorescence Microscopy (LISH-M) is a true fluorescence optical sectioning technique, first described by Heinrich Siedentopf in 1902 under the name of Ultramicroscopy. Light sheet microscopy utilises a plane of light to optically section samples. This allows deep imaging within transparent tissues and whole organisms. This book chapter will provide the reader with a comprehensive view on this emerging technology. https://www.leica-microsystems.com/science-lab/light-sheet-fluorescence-microscopy-beyond-the-flatlands/ Thu, 20 Dec 2012 14:05:00 +0000 https://www.leica-microsystems.com/6474 Basics in Microscopy How to Clean Microscope Optics Clean microscope optics are essential for obtaining good microscope images. If they are dirty, the microscope should be cleaned to avoid a loss of quality. If you decide to do this yourself, you should be extremely careful not to damage the sensitive microscope optics. https://www.leica-microsystems.com/science-lab/how-to-clean-microscope-optics/ Sun, 08 Jul 2012 22:00:00 +0000 Wymke Ockenga https://www.leica-microsystems.com/5988 Basics in Microscopy Optical Microscopes – Some Basics The optical microscope has been a standard tool in life science as well as material science for more than one and a half centuries now. To use this tool economically and effectively, it helps a lot to understand the basics of optics, especially of those essential components which are part of every microscope. https://www.leica-microsystems.com/science-lab/optical-microscopes-some-basics/ Wed, 02 May 2012 22:00:00 +0000 Helmut Rühl https://www.leica-microsystems.com/15667 Light Sheet Microscopy Selective Plane Illumination Microscopy Techniques in Developmental Biology Selective plane illumination microscopy (SPIM) and other fluorescence microscopy techniques in which a focused sheet of light serves to illuminate the sample have become increasingly popular in developmental studies. Fluorescence light-sheet microscopy bridges the gap in image quality between fluorescence stereomicroscopy and high-resolution imaging of fixed tissue sections. https://www.leica-microsystems.com/science-lab/selective-plane-illumination-microscopy-techniques-in-developmental-biology/ Mon, 15 Jun 2009 11:27:00 +0000