The Ages of Astrophotography
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Noise and ISO CS 178, Spring 2014
Noise and ISO CS 178, Spring 2014 Marc Levoy Computer Science Department Stanford University Outline ✦ examples of camera sensor noise • don’t confuse it with JPEG compression artifacts ✦ probability, mean, variance, signal-to-noise ratio (SNR) ✦ laundry list of noise sources • photon shot noise, dark current, hot pixels, fixed pattern noise, read noise ✦ SNR (again), dynamic range (DR), bits per pixel ✦ ISO ✦ denoising • by aligning and averaging multiple shots • by image processing will be covered in a later lecture 2 © Marc Levoy Nokia N95 cell phone at dusk • 8×8 blocks are JPEG compression • unwanted sinusoidal patterns within each block are JPEG’s attempt to compress noisy pixels 3 © Marc Levoy Canon 5D II at dusk • ISO 6400 • f/4.0 • 1/13 sec • RAW w/o denoising 4 © Marc Levoy Canon 5D II at dusk • ISO 6400 • f/4.0 • 1/13 sec • RAW w/o denoising 5 © Marc Levoy Canon 5D II at dusk • ISO 6400 • f/4.0 • 1/13 sec 6 © Marc Levoy Photon shot noise ✦ the number of photons arriving during an exposure varies from exposure to exposure and from pixel to pixel, even if the scene is completely uniform ✦ this number is governed by the Poisson distribution 7 © Marc Levoy Poisson distribution ✦ expresses the probability that a certain number of events will occur during an interval of time ✦ applicable to events that occur • with a known average rate, and • independently of the time since the last event ✦ if on average λ events occur in an interval of time, the probability p that k events occur instead is λ ke−λ p(k;λ) = probability k! density function 8 © Marc Levoy Mean and variance ✦ the mean of a probability density function p(x) is µ = ∫ x p(x)dx ✦ the variance of a probability density function p(x) is σ 2 = ∫ (x − µ)2 p(x)dx ✦ the mean and variance of the Poisson distribution are µ = λ σ 2 = λ ✦ the standard deviation is σ = λ Deviation grows slower than the average. -
Craters in Shadow
Section 3: Craters in Shadow Kepler Copernicus Eratosthenes Seen it Clavius Seen it Section 3: Craters in Shadow Visibility: A pair of binoculars is the minimum requirement to see these features. When: Look for them when the terminator’s close by, typically a day before last quarter. Not all craters are best seen when the Sun is high in the lunar sky - in fact most aren’t! If craters aren’t par- ticularly bright or dark, they tend to disappear into the background when the Moon’s phase is close to full. These craters are best seen when the ‘terminator’ is nearby, or when the Sun is low in the lunar sky as seen from the crater. This causes oblique lighting to fall on the crater and create exaggerated shadows. Ultimately, this makes the crater look more dramatic and easier to see. We’ll use this effect for the next section on lunar mountains, but before we do, there are a couple of craters that we’d like to bring to your attention. Actually, the Moon is covered with a whole host of wonderful craters that look amazing when the lighting is oblique. During the summer and into the early autumn, it’s the later phases of the Moon are best positioned in the sky - the phases following full Moon. Unfortunately, this means viewing in the early hours but don’t worry as we’ve kept things simple. We just want to give you a taste of what a shadowed crater looks like for this marathon, so the going here is really pretty easy! First, locate the two craters Kepler and Copernicus which were marathon targets pointed out in Section 2. -
Glossary Glossary
Glossary Glossary Albedo A measure of an object’s reflectivity. A pure white reflecting surface has an albedo of 1.0 (100%). A pitch-black, nonreflecting surface has an albedo of 0.0. The Moon is a fairly dark object with a combined albedo of 0.07 (reflecting 7% of the sunlight that falls upon it). The albedo range of the lunar maria is between 0.05 and 0.08. The brighter highlands have an albedo range from 0.09 to 0.15. Anorthosite Rocks rich in the mineral feldspar, making up much of the Moon’s bright highland regions. Aperture The diameter of a telescope’s objective lens or primary mirror. Apogee The point in the Moon’s orbit where it is furthest from the Earth. At apogee, the Moon can reach a maximum distance of 406,700 km from the Earth. Apollo The manned lunar program of the United States. Between July 1969 and December 1972, six Apollo missions landed on the Moon, allowing a total of 12 astronauts to explore its surface. Asteroid A minor planet. A large solid body of rock in orbit around the Sun. Banded crater A crater that displays dusky linear tracts on its inner walls and/or floor. 250 Basalt A dark, fine-grained volcanic rock, low in silicon, with a low viscosity. Basaltic material fills many of the Moon’s major basins, especially on the near side. Glossary Basin A very large circular impact structure (usually comprising multiple concentric rings) that usually displays some degree of flooding with lava. The largest and most conspicuous lava- flooded basins on the Moon are found on the near side, and most are filled to their outer edges with mare basalts. -
Making Your Own Astronomical Camera by Susan Kern and Don Mccarthy
www.astrosociety.org/uitc No. 50 - Spring 2000 © 2000, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. Making Your Own Astronomical Camera by Susan Kern and Don McCarthy An Education in Optics Dissect & Modify the Camera Loading the Film Turning the Camera Skyward Tracking the Sky Astronomy Camp for All Ages For More Information People are fascinated by the night sky. By patiently watching, one can observe many astronomical and atmospheric phenomena, yet the permanent recording of such phenomena usually belongs to serious amateur astronomers using moderately expensive, 35-mm cameras and to scientists using modern telescopic equipment. At the University of Arizona's Astronomy Camps, we dissect, modify, and reload disposed "One- Time Use" cameras to allow students to study engineering principles and to photograph the night sky. Elementary school students from Silverwood School in Washington state work with their modified One-Time Use cameras during Astronomy Camp. Photo courtesy of the authors. Today's disposable cameras are a marvel of technology, wonderfully suited to a variety of educational activities. Discarded plastic cameras are free from camera stores. Students from junior high through graduate school can benefit from analyzing the cameras' optics, mechanisms, electronics, light sources, manufacturing techniques, and economics. Some of these educational features were recently described by Gene Byrd and Mark Graham in their article in the Physics Teacher, "Camera and Telescope Free-for-All!" (1999, vol. 37, p. 547). Here we elaborate on the cameras' optical properties and show how to modify and reload one for astrophotography. An Education in Optics The "One-Time Use" cameras contain at least six interesting optical components. -
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,. 1. I , Har,.-apy (HC) icrofichs (MF) ff 063 July 06 i I BIBLIOGRAPHY OF CHE&CAL PRODUCTS OF VOLCANISM prepared by Paul Pushkar and Paul E. Damon - Prepared for the National Aeronautics and Space Administration (SC - NGR - 03 - 002 - 076) Laboratory of Geochronometry and Geochemistry Geochronology Department University of Arizona IE ie (PAGES) ,g1: Qjf-- 910 73 , (NASX~ROR TMX OR AD NUMBER) i BIBLIOGRAPHY OF CHEMICAL PRODUCTS OF VOLCANISM prepared by Paul Pushkar and Paul E. Damon Prepared for the National Aeronautics and Space Administration (SC - NGR - 03- 002 - 076) Laboratory of Geochronometry and Geochemistry Geochronology Department University of Arizona +. s i i Lunar Orbiter IV, Frame No. 157 THE EjARIUS HILLS: A LUNAR VOLCANIC FIELD? '- sa 3 TABLE OF CONTENTS Page Preface. 8 . i Acknowledgments . * a e . e i I Volcanic Gases and Sublimates, Gases Contained in Rocks, and Related Matters . e . 1 II Nongaseous Chemical Products of Terrestrial Volcanism . III Gas Content of Meteorites, Lunar Volcanfsm, and Related Subjects . 46 IV General References Dealing with Terrestrial Volcanism . 53 PREFACE This bibliography was compiled during a one-year literature search on possible volcanic products on the Moon. The bibliography is divided into four sections: I. Volcanic Gases and Sublimates, Gases Contained in Rocks, and Related Matters The literature in these fields, as emphasized recently by White and Waring (1963) is scanty, and for the most part by fiussian and Japanese scientists arid hence often presents difficulties in access and language to English-specking scientists. This section is believed to be fairly com- prehensive from the present to at least 1935. -
Sky and Telescope
SkyandTelescope.com The Lunar 100 By Charles A. Wood Just about every telescope user is familiar with French comet hunter Charles Messier's catalog of fuzzy objects. Messier's 18th-century listing of 109 galaxies, clusters, and nebulae contains some of the largest, brightest, and most visually interesting deep-sky treasures visible from the Northern Hemisphere. Little wonder that observing all the M objects is regarded as a virtual rite of passage for amateur astronomers. But the night sky offers an object that is larger, brighter, and more visually captivating than anything on Messier's list: the Moon. Yet many backyard astronomers never go beyond the astro-tourist stage to acquire the knowledge and understanding necessary to really appreciate what they're looking at, and how magnificent and amazing it truly is. Perhaps this is because after they identify a few of the Moon's most conspicuous features, many amateurs don't know where Many Lunar 100 selections are plainly visible in this image of the full Moon, while others require to look next. a more detailed view, different illumination, or favorable libration. North is up. S&T: Gary The Lunar 100 list is an attempt to provide Moon lovers with Seronik something akin to what deep-sky observers enjoy with the Messier catalog: a selection of telescopic sights to ignite interest and enhance understanding. Presented here is a selection of the Moon's 100 most interesting regions, craters, basins, mountains, rilles, and domes. I challenge observers to find and observe them all and, more important, to consider what each feature tells us about lunar and Earth history. -
Sky Notes by Neil Bone 2005 August & September
Sky notes by Neil Bone 2005 August & September below Castor and Pollux. Mercury is soon ing June and July, it is still quite possible that Sun and Moon lost from view again, arriving at superior con- noctilucent clouds (NLC) could be seen into junction beyond the Sun on September 18. early August, particularly by observers at The Sun continues its southerly progress along Venus continues its rather unfavourable more northerly locations. Quite how late into the ecliptic, reaching the autumnal equinox showing as an ‘Evening Star’. Although it August NLC can be seen remains to be deter- position at 22h 23m Universal Time (UT = pulls out to over 40° elongation east of the mined: there have been suggestions that the GMT; BST minus 1 hour) on September 22. Sun during September, Venus is also heading visibility period has become longer in recent At that precise time, the centre of the solar southwards, and as a result its setting-time years. Observational reports will be welcomed disk is positioned at the intersection between after the Sun remains much the same − barely by the Aurora Section. the celestial equator and the ecliptic, the latter an hour − during this interval. Although bright While declining sunspot activity makes great circle on the sky being inclined by 23.5° at magnitude −4, Venus will be quite tricky major aurorae extending to lower latitudes to the former. Calendrical autumn begins at the to catch in the early twilight: viewing cir- less likely, the appearance of coronal holes equinox, but amateur astronomers might more cumstances don’t really improve until the in the latter parts of the cycle does bring the readily follow meteorological timing, wherein closing weeks of 2005. -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
Staircase of Vienna Observatory (Institut Für Astronomie Der Universität Wien)
Figure 15.1: Staircase of Vienna Observatory (Institut für Astronomie der Universität Wien) 142 15. The University Observatory Vienna Anneliese Schnell (Vienna, Austria) 15.1 Introduction should prefer non-German instrument makers (E. Weiss 1873). In spring of 2008 the new Vienna Observatory was th commemorating its 125 anniversary, it was officially During a couple of years Vienna Observatory was edit- opened by Emperor Franz Joseph in 1883. Regular ob- ing an astronomical calendar. In the 1874 edition K. L. servations had started in 1880. Viennese astronomers Littrow wrote a contribution about the new observatory had planned that observatory for a long time. Already th in which he defined the instrumental needs: Karl von Littrow’s father had plans early in the 19 “für Topographie des Himmels ein mächtiges parallakti- century (at that time according to a letter from Joseph sches Fernrohr, ein dioptrisches Instrument von 25 Zoll Johann Littrow to Gauß from December 1, 1823 the Öffnung. Da sich aber ein Werkzeug von solcher Grö- observatory of Turku was taken as model) (Reich 2008), ße für laufende Beobachtungen (Ortsbestimmung neu- but it lasted until 1867 when it was decided to build a er Planeten und Kometen, fortgesetzte Doppelsternmes- new main building of the university of Vienna and also sungen, etc.) nicht eignet, ein zweites, kleineres, daher a new observatory. Viennese astronomers at that time leichter zu handhabendes, aber zur Beobachtung licht- had an excellent training in mathematics, they mostly schwacher Objekte immer noch hinreichendes Teleskop worked on positional astronomy and celestial mechanics. von etwa 10 Zoll Öffnung, und ein Meridiankreis er- They believed in F. -
Orion Newtonian Astrograph Instruction Manual
INSTRUCTION MANUAL Orion 8" and 10" f/3.9 Newtonian Astrographs #8297 8" f/3.9, #8296 10" f/3.9 #8296 Providing Exceptional Consumer Optical Products Since 1975 OrionTelescopes.com Customer Support (800) 676-1343 • E-mail: [email protected] Corporate Offices (831) 763-7000 • 89 Hangar Way, Watsonville, CA 95076 © 2011 Orion Telescopes & Binoculars IN 406 Rev. A 07/11 2" Finder scope Accessory bracket collar 9x50 Finder Scope Optical tube Tube rings Focus wheel Drawtube Fine focus wheel tensioning thumbscrew Focus wheel Figure 1. The Orion 8" f/3.9 Newtonian Astrograph Congratulations on your purchase of an Orion f/3.9 Newtonian Astrograph! These powerful imaging telescopes feature “fast,” high-quality parabolic optics, a 2" dual-speed Crayford focuser, and excellent mechanical construction with some special features. Optimized for astrophotography with DSLR and astronomical CCD imaging cameras, our f/3.9 Newtonian Astrographs are capable of delivering breathtak- ing imaging performance – for beginning to advanced astrophotographers. This instruction manual covers both the 8" and 10" mod- Parts List els of f/3.9 Newtonian astrograph. Although they differ • Optical tube assembly in aperture and focal length, physical size, and weight, they are otherwise very similar in mechanical construc- • Optical tube dust cap tion and features. So we will use the 8" model to illus- • 1.25" eyepiece holder trate the features of both astrographs. Any exceptions • 9x50 finder scope with bracket related to the 10" model will be noted. • Pair of hinged tube rings This instruction manual will help you to set up and • 2" thread-on extension adapter, 30mm properly use your telescope. -
List of Bright Nebulae Primary I.D. Alternate I.D. Nickname
List of Bright Nebulae Alternate Primary I.D. Nickname I.D. NGC 281 IC 1590 Pac Man Neb LBN 619 Sh 2-183 IC 59, IC 63 Sh2-285 Gamma Cas Nebula Sh 2-185 NGC 896 LBN 645 IC 1795, IC 1805 Melotte 15 Heart Nebula IC 848 Soul Nebula/Baby Nebula vdB14 BD+59 660 NGC 1333 Embryo Neb vdB15 BD+58 607 GK-N1901 MCG+7-8-22 Nova Persei 1901 DG 19 IC 348 LBN 758 vdB 20 Electra Neb. vdB21 BD+23 516 Maia Nebula vdB22 BD+23 522 Merope Neb. vdB23 BD+23 541 Alcyone Neb. IC 353 NGC 1499 California Nebula NGC 1491 Fossil Footprint Neb IC 360 LBN 786 NGC 1554-55 Hind’s Nebula -Struve’s Lost Nebula LBN 896 Sh 2-210 NGC 1579 Northern Trifid Nebula NGC 1624 G156.2+05.7 G160.9+02.6 IC 2118 Witch Head Nebula LBN 991 LBN 945 IC 405 Caldwell 31 Flaming Star Nebula NGC 1931 LBN 1001 NGC 1952 M 1 Crab Nebula Sh 2-264 Lambda Orionis N NGC 1973, 1975, Running Man Nebula 1977 NGC 1976, 1982 M 42, M 43 Orion Nebula NGC 1990 Epsilon Orionis Neb NGC 1999 Rubber Stamp Neb NGC 2070 Caldwell 103 Tarantula Nebula Sh2-240 Simeis 147 IC 425 IC 434 Horsehead Nebula (surrounds dark nebula) Sh 2-218 LBN 962 NGC 2023-24 Flame Nebula LBN 1010 NGC 2068, 2071 M 78 SH 2 276 Barnard’s Loop NGC 2149 NGC 2174 Monkey Head Nebula IC 2162 Ced 72 IC 443 LBN 844 Jellyfish Nebula Sh2-249 IC 2169 Ced 78 NGC Caldwell 49 Rosette Nebula 2237,38,39,2246 LBN 943 Sh 2-280 SNR205.6- G205.5+00.5 Monoceros Nebula 00.1 NGC 2261 Caldwell 46 Hubble’s Var. -
198 7Apjs. . .63. .645U the Astrophysical Journal Supplement
.645U The Astrophysical Journal Supplement Series, 63:645-660,1987 March © 1987. The American Astronomical Society. All rights reserved. Printed in U.S.A. .63. 7ApJS. A CO SURVEY OF THE DARK NEBULAE IN PERSEUS, TAURUS, AND AURIGA 198 H. Ungerechts and P. Thaddeus Goddard Institute for Space Studies and Columbia University Received 1986 February 20; accepted 1986 September 4 ABSTRACT A region of 750 square degrees including the well-known dark nebulae in Perseus, Taurus, and Auriga was surveyed in the 115 GHz, J = l-0 line of CO at an angular resolution of 0?5. The spectral resolution of the survey is 250 kHz, or 0.65 km s-1, and the rms noise per spectrometer channel is 0.14 K. Emission was detected from nearly 50% of the observed positions; most positions with emission are in the Taurus-Auriga dark nebulae, a cloud associated with IC 348 and NGC 1333, and a cloud associated with the California nebula (NGC 1499) and NGC 1579, which overlaps the northern Taurus-Auriga nebulae but is separated from them in velocity. Other objects seen in this survey are several small clouds at Galactic latitude —25° to —35° southwest of the Taurus clouds, and the L1558 and L1551 clouds in the south. The mass of each of the IC 348 and NGC 1499 4 4 clouds is about 5X10 M0, and that of the Taurus-Auriga clouds about 3.5 X10 M0; the total mass of all 5 clouds surveyed is about 2x10 Af0. On a large scale, the rather quiescent Taurus clouds are close to virial equilibrium, but the IC 348 and NGC 1499 clouds are more dynamically active.