Leica Science Lab - Tag : Objective https://www.leica-microsystems.com//science-lab/tag/tags/objective/show/Tag/ Article tagged with Objective en-US 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/18925 Super-Resolution Confocal Microscopy Image Restoration and Deconvolution Methods to Calibrate and Scale Axial Distances in Confocal Microscopy as a Function of Refractive Index Application example of HyVolution Super-Resolution - Accurate distance measurement in 3D confocal microscopy is important for quantitative analysis, volume visualization and image restoration. However, axial distances can be distorted by both the point spread function (PSF) and by a refractive-index mismatch between the sample and immersion liquid, which are difficult to separate. Additionally, accurate calibration of the axial distances in confocal microscopy remains cumbersome, although several high-end methods exist. In this paper we present two methods to calibrate axial distances in 3D confocal microscopy that are both accurate and easily implemented. https://www.leica-microsystems.com//science-lab/methods-to-calibrate-and-scale-axial-distances-in-confocal-microscopy-as-a-function-of-refractive-index/ Fri, 09 Dec 2016 08:29:00 +0000 https://www.leica-microsystems.com/19036 Basics in Microscopy Live-Cell Imaging Fluorescence 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, 08 Dec 2016 15:22:00 +0000 Dr. Christoph Greb 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/18779 Multiphoton Microscopy BABB Clearing and Imaging for High Resolution Confocal Microscopy: Counting and Sizing Kidney Cells in the 21st Century Multipohoton microscopy experiment using Leica TCS SP8 MP and Leica 20x/0.95 NA BABB immersion objective. Understanding kidney microanatomy is key to detecting and identifying early events in kidney disease. Improvements in tissue clearing and imaging have been crucial in this field, and now we report on a novel, time-efficient method to study podocyte depletion in renal glomeruli using a combination of immunofluorescence, optical clearing, confocal microscopy and 3D analysis. https://www.leica-microsystems.com//science-lab/babb-clearing-and-imaging-for-high-resolution-confocal-microscopy-counting-and-sizing-kidney-cells-in-the-21st-century/ Tue, 13 Sep 2016 09:03:00 +0000 Ph.D. Victor G. Puelles, Prof. John F. Bertram, MSc Stephen Firth, Prof. Ian Harper 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/16095 Stereo Microscopy How to Correct Aberration in Stereo Microscopy by Using the Right Objective Lenses For samples/specimens immersed in a liquid or embedded in a polymer, high quality microscopic observation can be hindered as a result of spherical aberration. An objective which can correct for refractive index mismatch allows images with greatly reduced spherical aberration and sharper focus to be obtained. https://www.leica-microsystems.com//science-lab/how-to-correct-aberration-in-stereo-microscopy-by-using-the-right-objective-lenses/ Fri, 21 Aug 2015 17:27:00 +0000 PhD James DeRose, PhD Heinrich Bürgers 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/2472 Basics in Microscopy Widefield Microscopy Beware of "Empty" Magnification This article explains how to avoid the phenomen of "empty magnification" in microscopy. https://www.leica-microsystems.com//science-lab/beware-of-empty-magnification/ Sun, 18 May 2008 10:00:00 +0000 Dipl. oec.-troph. Anja Schué