The Properties and Testing of Optical Instruments - 2d Edition - Issued August 9, 1918

Sep 15, 2026

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A Bureau of Standards circular explaining the main properties, imperfections, and testing methods of optical instruments. It introduces a classification covering observation, reproduction, and measurement instruments, then details key observation properties such as definition and resolving power, magnification, brightness of image, and field of view. It also discusses how design, lens correction, and workmanship determine performance, and why practical instruments require compromise between desired properties.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages44

Reading Time1 h 51 min

AccessFree to download

Contents

I. Classification of optical instruments

II. Properties of optical instruments

1. Instruments for observation

2. Instruments for reproduction

3. Instruments for measurement

III. Testing of optical instruments

IV. Tests by Bureau of Standards

OF THE BUREAU OF STANDARDS S.W.STRATTON,DIRECTOR No.27 THE PROPERTIES AND TESTING OFOPTICAL INSTRUMENTS (2d Edition) iSSUED AUGUST 9,1918 PRICE,10 CENTS Sold only by the Superintendent of Documents,Government Printing OfficeWashington,D.C. BUREAU OF STANDARDS S.W.STRATTON,DIRECTOR No.27 THE PROPERTIES AND TESTING OFOPTICAL INSTRUMENTS 〔2d Edition〕 ISSUED AUGUST 9,1918 PRICE,10 CENTS Sold only by the Superintendent of Documents,Government Printing OfficeWashington,D.C. WASHINGTONGOVERNMENT PRINTING OFFICE THE PROPERTIES AND TESTING OF OPTICAL INSTRUMENTS¹ --— CONTENTS Page I. Classification of optical instruments………………………………………………………………………3 II. Properties of optical instruments…………………………………………………………………………………4 I. Instruments for observation……………………………………………………………………………5 (I)Definition and resolving power………………………………………………………5(2)Magnification………………………………………………………………………………………8 (3)Brightness of image…………………………………………………………………………II (4)Field of view…………………………………………………………………………………………………I9 (a)Erecting systems…………………………………………………………………………………20 (b) Stereoscopic vision…………………………………………………………………………2I 2.Instruments for reproduction…………………………………………………………………………22 (I)Monochromatic aberrations………………………………………………………………22 (a) Spherical aberration……………………………………………………23 (b) Coma……………………………………………………………………………………………24 (c)Astigmatism………………………………………………………………………25 (d) Curvature of field……………………………………………………………………26 (e) Distortion………………………………………………………………………………………26 (2) Chromatic or color aberrations………………………………………………………27 (a)Axial chromatism…………………………………………………………………27 (b)Lateral chromatism…………………………………………………………………28 (3) Corrected lenses……………………………………………………………………………………28 3. Instruments for measurement……………………………………………29 III. Testing of optical instruments………………………………………………………………………………………3I IV. Tests by Bureau of Standards…………………………………………………………………………………………38 I. Description of tests……………………………………………………………………………………38 2.Regulations concerning tests……………………………………………………………………………39 3. Schedule of fees for optical testing…………………………………………………………40 I. CLASSIFICATION OF OPTICAL INSTRUMENTS Optical instruments, in general, may be divided, roughly, into three classes, as follows: I. Instruments for observation: Spectacle lenses, reading glasses, opera glasses, field glasses, telescopes, periscopes, micro- scopes, etc. 2. Instruments for reproduction: Camera lenses, photographic telescopes, photomicrographic cameras, condenser lenses, pro- jection lenses, etc. 3.Instruments for measurement:(a)of directions—sextants,theodolites,spectrometers,etc.;(b)of light intensities—photom-eters;(c)of polarized light—polarimeters,saccharimeters;(d)of distances—range finders,interferometers,etc. # II.PROPERTIES OF OPTICAL INSTRUMENTS The properties of all optical instruments depend partly upontheir general design and partly upon the degree of correction andworkmanship attained in the lenses and other parts used in theirconstruction. It is impossible to make optical instruments which are perfectin every way,so the design of all optical instruments is,therefore,a compromise giving the maximum of those properties most de-sirable for the use to which the particular instrument is to be put.In some instruments(e.g.,spectacles,hand magnifiers,condensers,low-power telescopes)the requirements are not severe and areeasily met,while in others (e.g.,photographic lenses,microscopes,periscopes)the severest demands are made on both designer andconstructor.In this circular the important properties of differenttypes of optical instruments are discussed in an elementary way,and methods are described for testing the performance of eachtype of instrument. In recent years,many types of optical instruments have beendeveloped and have come into more or less common use.At thesame time,a great deal has been written in the English languageon optical subjects,but there is no general discussion of op

FAQs

How does the circular classify optical instruments?

Optical instruments are divided into three broad classes: instruments for observation, instruments for reproduction, and instruments for measurement.

Why can optical instruments not be perfect in every way?

Because they require design compromises to achieve the maximum of the most desirable properties for their intended use, balancing correction and workmanship.

What key properties of observation instruments are emphasized?

The circular highlights definition and resolving power, magnification, brightness of image, and field of view as the most important characteristics.

Sep 15, 2026

Uploaded by Terk