Lab 11: the Compound Microscope
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Galileo and the Telescope
Galileo and the Telescope A Discussion of Galileo Galilei and the Beginning of Modern Observational Astronomy ___________________________ Billy Teets, Ph.D. Acting Director and Outreach Astronomer, Vanderbilt University Dyer Observatory Tuesday, October 20, 2020 Image Credit: Giuseppe Bertini General Outline • Telescopes/Galileo’s Telescopes • Observations of the Moon • Observations of Jupiter • Observations of Other Planets • The Milky Way • Sunspots Brief History of the Telescope – Hans Lippershey • Dutch Spectacle Maker • Invention credited to Hans Lippershey (c. 1608 - refracting telescope) • Late 1608 – Dutch gov’t: “ a device by means of which all things at a very great distance can be seen as if they were nearby” • Is said he observed two children playing with lenses • Patent not awarded Image Source: Wikipedia Galileo and the Telescope • Created his own – 3x magnification. • Similar to what was peddled in Europe. • Learned magnification depended on the ratio of lens focal lengths. • Had to learn to grind his own lenses. Image Source: Britannica.com Image Source: Wikipedia Refracting Telescopes Bend Light Refracting Telescopes Chromatic Aberration Chromatic aberration limits ability to distinguish details Dealing with Chromatic Aberration - Stop Down Aperture Galileo used cardboard rings to limit aperture – Results were dimmer views but less chromatic aberration Galileo and the Telescope • Created his own (3x, 8-9x, 20x, etc.) • Noted by many for its military advantages August 1609 Galileo and the Telescope • First observed the -
Multiphysics Modeling, Sensitivity Analysis, and Optical Performance Optimization for Optical Laser Head in Additive Manufacturing
applied sciences Article Multiphysics Modeling, Sensitivity Analysis, and Optical Performance Optimization for Optical Laser Head in Additive Manufacturing Jiaping Yang 1, Xiling Yao 1,* , Yuxin Cai 1,2 and Guijun Bi 1,* 1 Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, Singapore 637662, Singapore; [email protected] (J.Y.); [email protected] (Y.C.) 2 School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore * Correspondence: [email protected] (X.Y.); [email protected] (G.B.) Abstract: Optical laser head is a key component used to shape the laser beam and to deliver higher power laser irradiation onto workpieces for material processing. A focused laser beam size and optical intensity need to be controlled to avoid decreasing beam quality and loss of intensity in laser material processing. This paper reports the multiphysics modeling of an in-house developed laser head for laser-aided additive manufacturing (LAAM) applications. The design of computer experiments (DoCE) combined with the response surface model was used as an efficient design approach to optimize the optical performance of a high power LAAM head. A coupled structural- thermal-optical-performance (STOP) model was developed to evaluate the influence of thermal effects on the optical performance. A number of experiments with different laser powers, laser beam focal plane positions, and environmental settings were designed and simulated using the STOP model for sensitivity analysis. The response models of the optical performance were constructed using DoCE and regression analysis. Based on the response models, optimal design settings were predicted and validated with the simulations. -
Statement by the Association of Hoving Image Archivists (AXIA) To
Statement by the Association of Hoving Image Archivists (AXIA) to the National FTeservation Board, in reference to the Uational Pilm Preservation Act of 1992, submitted by Dr. Jan-Christopher Eorak , h-esident The Association of Moving Image Archivists was founded in November 1991 in New York by representatives of over eighty American and Canadian film and television archives. Previously grouped loosely together in an ad hoc organization, Pilm Archives Advisory Committee/Television Archives Advisory Committee (FAAC/TAAC), it was felt that the field had matured sufficiently to create a national organization to pursue the interests of its constituents. According to the recently drafted by-laws of the Association, AHIA is a non-profit corporation, chartered under the laws of California, to provide a means for cooperation among individuals concerned with the collection, preservation, exhibition and use of moving image materials, whether chemical or electronic. The objectives of the Association are: a.) To provide a regular means of exchanging information, ideas, and assistance in moving image preservation. b.) To take responsible positions on archival matters affecting moving images. c.) To encourage public awareness of and interest in the preservation, and use of film and video as an important educational, historical, and cultural resource. d.) To promote moving image archival activities, especially preservation, through such means as meetings, workshops, publications, and direct assistance. e. To promote professional standards and practices for moving image archival materials. f. To stimulate and facilitate research on archival matters affecting moving images. Given these objectives, the Association applauds the efforts of the National Film Preservation Board, Library of Congress, to hold public hearings on the current state of film prese~ationin 2 the United States, as a necessary step in implementing the National Film Preservation Act of 1992. -
Compound Light Microscopes Magnification
Compound Light Microscopes • Frequently used tools of biologists. • Magnify organisms too small to be seen with the unaided eye. • To use: – Sandwich specimen between transparent slide and thin, transparent coverslip. – Shine light through specimen into lenses of microscope. • Lens closest to object is objective lens. • Lens closest to your eye is the ocular lens. • The image viewed through a compound light microscope is formed by the projection of light through a mounted specimen on a slide. Eyepiece/ ocular lens Magnification Nosepiece Arm Objectives/ • Magnification - the process of objective lens enlarging something in appearance, not Stage Clips Light intensity knob actual physical size. Stage Coarse DiaphragmDiaphragm Adjustment Fine Adjustment Light Positioning knobs Source Base Always carry a microscope with one hand holding the arm and one hand under the base. What’s my power? Comparing Powers of Magnification To calculate the power of magnification or total magnification, multiply the power of the ocular lens by the We can see better details with higher power of the objective. the powers of magnification, but we cannot see as much of the image. Which of these images would be viewed at a higher power of magnification? 1 Resolution Limit of resolution • Resolution - the shortest distance • As magnifying power increases, we see between two points more detail. on a specimen that • There is a point where we can see no can still be more detail is the limit of resolution. distinguished as – Beyond the limit of resolution, objects get two points. blurry and detail is lost. – Use electron microscopes to reveal detail beyond the limit of resolution of a compound light microscope! Proper handling technique Field of view 1. -
Object-Image Real Image Virtual Image
Object-Image • A physical object is usually observed by reflected light that diverges from the object. • An optical system (mirrors or lenses) can 3.1 Images formed by Mirrors and Lenses produce an image of the object by redirecting the light. • Images – Real Image • Image formation by mirrors – Virtual Image • Images formed by lenses Real Image Virtual Image Optical System ing diverging erg converging diverging diverging div Object Object real Image Optical System virtual Image Light appears to come from the virtual image but does not Light passes through the real image pass through the virtual image Film at the position of the real image is exposed. Film at the position of the virtual image is not exposed. Each point on the image can be determined Image formed by a plane mirror. by tracing 2 rays from the object. B p q B’ Object Image The virtual image is formed directly behind the object image mirror. Light does not A pass through A’ the image mirror A virtual image is formed by a plane mirror at a distance q behind the mirror. q = -p 1 Parabolic Mirrors Parabolic Reflector Optic Axis Parallel rays reflected by a parabolic mirror are focused at a point, called the Parabolic mirrors can be used to focus incoming parallel rays to a small area Focal Point located on the optic axis. or to direct rays diverging from a small area into parallel rays. Spherical mirrors Parallel beams focus at the focal point of a Concave Mirror. •Spherical mirrors are much easier to fabricate than parabolic mirrors • A spherical mirror is an approximation of a parabolic Focal point mirror for small curvatures. -
Depth of Focus (DOF)
Erect Image Depth of Focus (DOF) unit: mm Also known as ‘depth of field’, this is the distance (measured in the An image in which the orientations of left, right, top, bottom and direction of the optical axis) between the two planes which define the moving directions are the same as those of a workpiece on the limits of acceptable image sharpness when the microscope is focused workstage. PG on an object. As the numerical aperture (NA) increases, the depth of 46 focus becomes shallower, as shown by the expression below: λ DOF = λ = 0.55µm is often used as the reference wavelength 2·(NA)2 Field number (FN), real field of view, and monitor display magnification unit: mm Example: For an M Plan Apo 100X lens (NA = 0.7) The depth of focus of this objective is The observation range of the sample surface is determined by the diameter of the eyepiece’s field stop. The value of this diameter in 0.55µm = 0.6µm 2 x 0.72 millimeters is called the field number (FN). In contrast, the real field of view is the range on the workpiece surface when actually magnified and observed with the objective lens. Bright-field Illumination and Dark-field Illumination The real field of view can be calculated with the following formula: In brightfield illumination a full cone of light is focused by the objective on the specimen surface. This is the normal mode of viewing with an (1) The range of the workpiece that can be observed with the optical microscope. With darkfield illumination, the inner area of the microscope (diameter) light cone is blocked so that the surface is only illuminated by light FN of eyepiece Real field of view = from an oblique angle. -
Image Compression Using Discrete Cosine Transform Method
Qusay Kanaan Kadhim, International Journal of Computer Science and Mobile Computing, Vol.5 Issue.9, September- 2016, pg. 186-192 Available Online at www.ijcsmc.com International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology ISSN 2320–088X IMPACT FACTOR: 5.258 IJCSMC, Vol. 5, Issue. 9, September 2016, pg.186 – 192 Image Compression Using Discrete Cosine Transform Method Qusay Kanaan Kadhim Al-Yarmook University College / Computer Science Department, Iraq [email protected] ABSTRACT: The processing of digital images took a wide importance in the knowledge field in the last decades ago due to the rapid development in the communication techniques and the need to find and develop methods assist in enhancing and exploiting the image information. The field of digital images compression becomes an important field of digital images processing fields due to the need to exploit the available storage space as much as possible and reduce the time required to transmit the image. Baseline JPEG Standard technique is used in compression of images with 8-bit color depth. Basically, this scheme consists of seven operations which are the sampling, the partitioning, the transform, the quantization, the entropy coding and Huffman coding. First, the sampling process is used to reduce the size of the image and the number bits required to represent it. Next, the partitioning process is applied to the image to get (8×8) image block. Then, the discrete cosine transform is used to transform the image block data from spatial domain to frequency domain to make the data easy to process. -
Ground-Based Photographic Monitoring
United States Department of Agriculture Ground-Based Forest Service Pacific Northwest Research Station Photographic General Technical Report PNW-GTR-503 Monitoring May 2001 Frederick C. Hall Author Frederick C. Hall is senior plant ecologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, Natural Resources, P.O. Box 3623, Portland, Oregon 97208-3623. Paper prepared in cooperation with the Pacific Northwest Region. Abstract Hall, Frederick C. 2001 Ground-based photographic monitoring. Gen. Tech. Rep. PNW-GTR-503. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 340 p. Land management professionals (foresters, wildlife biologists, range managers, and land managers such as ranchers and forest land owners) often have need to evaluate their management activities. Photographic monitoring is a fast, simple, and effective way to determine if changes made to an area have been successful. Ground-based photo monitoring means using photographs taken at a specific site to monitor conditions or change. It may be divided into two systems: (1) comparison photos, whereby a photograph is used to compare a known condition with field conditions to estimate some parameter of the field condition; and (2) repeat photo- graphs, whereby several pictures are taken of the same tract of ground over time to detect change. Comparison systems deal with fuel loading, herbage utilization, and public reaction to scenery. Repeat photography is discussed in relation to land- scape, remote, and site-specific systems. Critical attributes of repeat photography are (1) maps to find the sampling location and of the photo monitoring layout; (2) documentation of the monitoring system to include purpose, camera and film, w e a t h e r, season, sampling technique, and equipment; and (3) precise replication of photographs. -
The Microscope Parts And
The Microscope Parts and Use Name:_______________________ Period:______ Historians credit the invention of the compound microscope to the Dutch spectacle maker, Zacharias Janssen, around the year 1590. The compound microscope uses lenses and light to enlarge the image and is also called an optical or light microscope (vs./ an electron microscope). The simplest optical microscope is the magnifying glass and is good to about ten times (10X) magnification. The compound microscope has two systems of lenses for greater magnification, 1) the ocular, or eyepiece lens that one looks into and 2) the objective lens, or the lens closest to the object. Before purchasing or using a microscope, it is important to know the functions of each part. Eyepiece Lens: the lens at the top that you look through. They are usually 10X or 15X power. Tube: Connects the eyepiece to the objective lenses Arm: Supports the tube and connects it to the base. It is used along with the base to carry the microscope Base: The bottom of the microscope, used for support Illuminator: A steady light source (110 volts) used in place of a mirror. Stage: The flat platform where you place your slides. Stage clips hold the slides in place. Revolving Nosepiece or Turret: This is the part that holds two or more objective lenses and can be rotated to easily change power. Objective Lenses: Usually you will find 3 or 4 objective lenses on a microscope. They almost always consist of 4X, 10X, 40X and 100X powers. When coupled with a 10X (most common) eyepiece lens, we get total magnifications of 40X (4X times 10X), 100X , 400X and 1000X. -
How Do the Lenses in a Microscope Work?
Student Name: _____________________________ Date: _________________ How do the lenses in a microscope work? Compound Light Microscope: A compound light microscope uses light to transmit an image to your eye. Compound deals with the microscope having more than one lens. Microscope is the combination of two words; "micro" meaning small and "scope" meaning view. Early microscopes, like Leeuwenhoek's, were called simple because they only had one lens. Simple scopes work like magnifying glasses that you have seen and/or used. These early microscopes had limitations to the amount of magnification no matter how they were constructed. The creation of the compound microscope by the Janssens helped to advance the field of microbiology light years ahead of where it had been only just a few years earlier. The Janssens added a second lens to magnify the image of the primary (or first) lens. Simple light microscopes of the past could magnify an object to 266X as in the case of Leeuwenhoek's microscope. Modern compound light microscopes, under optimal conditions, can magnify an object from 1000X to 2000X (times) the specimens original diameter. "The Compound Light Microscope." The Compound Light Microscope. Web. 16 Feb. 2017. http://www.cas.miamioh.edu/mbi-ws/microscopes/compoundscope.html Text is available under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license. - 1 – Student Name: _____________________________ Date: _________________ Now we will describe how a microscope works in somewhat more detail. The first lens of a microscope is the one closest to the object being examined and, for this reason, is called the objective. -
A. Introduction B. Magnification, Resolution, and Working Distance
SOURCE: http://abacus.bates.edu/~ganderso/biology/resources/microscopy.html Compound Microscopes | mag vs resolution | working distance | monocular parts | care of the microscopes | | monocular focusing | oil immersion | measuring field diameter | binocular parts | binocular focusing | | Microscopy Exercises | A. Introduction The typical compound light microscope (Fig.1) is capable of increasing our ability to see detail by 1000 times so that objects as small as 0.1 micrometer (um) or 100 nanometers (nm) can be seen. Electron microscopes extend this range further allowing us to see objects as small as 0.5 nm in diameter or roughly 1/200,000th the size we can see with a naked eye. Needless to say, development and use of microscopes has vastly improved our understanding of cells and their structure and function. Figure 1. Binocular compound microscope. B. Magnification, Resolution, and Working Distance Magnification is simply a function of making an object appear bigger, such as when we use a hand lens to enlarge printed word. Merely magnifying an object without a simultaneous increase in the amount of detail seen will not provide the viewer with a good image. The ability of a microscope (or eye) to see detail is a function of its resolving power. Resolving power is defined as the minimum distance between two objects at which the objects can just be distinguished as separate and is a function of the wavelength of light used and the quality of the optics. In general, the shorter the wavelength of the light source, the higher the resolution of the microscope. Working distance is the distance between the objective lens and the specimen. -
Lecture 37: Lenses and Mirrors
Lecture 37: Lenses and mirrors • Spherical lenses: converging, diverging • Plane mirrors • Spherical mirrors: concave, convex The animated ray diagrams were created by Dr. Alan Pringle. Terms and sign conventions for lenses and mirrors • object distance s, positive • image distance s’ , • positive if image is on side of outgoing light, i.e. same side of mirror, opposite side of lens: real image • s’ negative if image is on same side of lens/behind mirror: virtual image • focal length f positive for concave mirror and converging lens negative for convex mirror and diverging lens • object height h, positive • image height h’ positive if the image is upright negative if image is inverted • magnification m= h’/h , positive if upright, negative if inverted Lens equation 1 1 1 푠′ ℎ′ + = 푚 = − = magnification 푠 푠′ 푓 푠 ℎ 푓푠 푠′ = 푠 − 푓 Converging and diverging lenses f f F F Rays refract towards optical axis Rays refract away from optical axis thicker in the thinner in the center center • there are focal points on both sides of each lens • focal length f on both sides is the same Ray diagram for converging lens Ray 1 is parallel to the axis and refracts through F. Ray 2 passes through F’ before refracting parallel to the axis. Ray 3 passes straight through the center of the lens. F I O F’ object between f and 2f: image is real, inverted, enlarged object outside of 2f: image is real, inverted, reduced object inside of f: image is virtual, upright, enlarged Ray diagram for diverging lens Ray 1 is parallel to the axis and refracts as if from F.