1、BRITISH STANDARD BS ISO 14490-1:2005 Optics and optical instruments Test methods for telescopic systems Part 1: Test methods for basic characteristics ICS 37.020 BS ISO 14490-1:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 12 January 2
2、006 BSI 12 January 2006 ISBN 0 580 47134 9 National foreword This British Standard reproduces verbatim ISO 14490-1:2005 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee CPW/172, Optics and optical instruments, which has the r
3、esponsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A l
4、ist of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Corresp
5、ondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of
6、 itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 14, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the
7、 document was last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 14490-1:2005(E)INTERNATIONAL STANDARD ISO 14490-1 First edition 2005-10-15 Optics and optical instruments Test methods for telescopic systems Part 1: Test methods for basic characteristics Opti
8、que et instruments doptique Mthodes dessai pour systmes tlescopiques Partie 1: Mthodes dessai des caractristiques fondamentales BS ISO 14490-1:2005ii BS ISO 14490-1:2005 iii Contents Page Foreword. v 1 Scope 1 2 Normative references 1 3 Terms and definitions .1 4 Method of measurement of the angular
9、 magnification2 4.1 General2 4.2 Test arrangement.2 4.3 Procedure .3 4.4 Determination of results .3 4.5 Test report 3 5 Method of measurement of the entrance pupil diameter.3 5.1 General3 5.2 Test arrangement.3 5.3 Procedure .4 5.4 Determination of results .4 5.5 Test report 4 6 Method of measureme
10、nt of the exit pupil diameter and eye relief .4 6.1 General4 6.2 Test arrangement.5 6.3 Procedure .5 6.4 Determination of results .5 6.5 Test report 6 7 Method of measurement of the angular field of view in the object space .6 7.1 General6 7.2 Test arrangement.6 7.3 Procedure .6 7.4 Determination of
11、 results .7 7.5 Test report 7 8 Method of measurement of the angular field of view in the image space .7 8.1 General7 8.2 Test arrangement.7 8.3 Procedure .8 8.4 Determination of results .9 8.5 Test report 9 9 Method of measurement of the angular field of view in the object space for spectacle weare
12、rs .9 9.1 General9 9.2 Test arrangement.9 9.3 Procedure .9 9.4 Determination of results .11 9.5 Test report 11 10 Method of measurement of the collimation of rays emergent from the eyepiece 11 10.1 General11 10.2 Test arrangement.11 10.3 Procedure .12 10.4 Determination of results .12 10.5 Test repo
13、rt 12 BS ISO 14490-1:2005 iv 11 Method of measurement of the image rotation 12 11.1 General . 12 11.2 Test arrangement 12 11.3 Procedure. 13 11.4 Determination of results. 13 11.5 Test report 13 12 Method of determination of the closest distance of observation 14 12.1 General . 14 12.2 Test arrangem
14、ent 14 12.3 Procedure. 14 12.4 Determination of results. 14 12.5 Test report 14 13 General test report 14 v Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is n
15、ormally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part i
16、n the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prep
17、are International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that s
18、ome of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 14490-1 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 4, Telescopic systems. ISO 14490 consists of th
19、e following parts, under the general title Optics and optical instruments Test methods for telescopic systems: Part 1: Test methods for basic characteristics Part 2: Test methods for binocular systems Part 3: Test methods for telescopic sights Part 4: Test methods for astronomical telescopes Part 5:
20、 Test methods for transmittance Part 6: Test methods for veiling glare index Part 7: Test methods for limit of resolution The following part is under preparation: Part 8: Test methods for night-vision devices BS ISO 14490-1:2005blank1 Optics and optical instruments Test methods for telescopic system
21、s Part 1: Test methods for basic characteristics 1 Scope This part of ISO 14490 specifies the test methods for the determination of the following basic characteristics of telescopic systems and observational telescopic instruments: angular magnification (see Clause 4); entrance pupil diameter (see C
22、lause 5); exit pupil diameter and eye relief (see Clause 6); angular field of view in the object space (see Clause 7); angular field of view in the image space (see Clause 8); angular field of view in the object space for spectacle wearers (see Clause 9); collimation of the bundle of rays emergent f
23、rom the eyepiece (see Clause 10); image rotation (see Clause 11); closest distance of observation (see Clause 12). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refer
24、ences, the latest edition of the referenced document (including any amendments) applies. ISO 14132-1:2002, Optics and optical instruments Vocabulary for telescopic systems Part 1: General terms and alphabetical indexes of terms in ISO 14132 3 Terms and definitions For the purposes of this document,
25、the terms and definitions given in ISO 14132-1 apply. BS ISO 14490-1:20052 4 Method of measurement of the angular magnification 4.1 General In accordance with ISO 14132-1, the angular magnification of a telescopic system is defined by the following equation: tan tan ww ww = (1) where w and w are ang
26、les that the axes of conjugate beams make with the optical axis in the object space and image space, respectively. The method of measurement of the angular magnification is based on the measurement of the angular size of an object placed in the field of view of a test specimen and that of its image.
27、 4.2 Test arrangement Measurement of the magnification shall be carried out with the angular test arrangement shown in Figure 1. For systems for which the magnification is to be measured under a focus setting other than infinity, the collimator scale shall be adjusted in order to form the image of t
28、he scale at the specified distance from the test specimen. The test arrangement shall be provided with a green optical filter to avoid any chromatism of the image. The maximum transmittance of the filter shall be at a wavelength of about 0,55 m. As an optical angular measuring device, one of the fol
29、lowing shall be used: a telescope with a scale having divisions of known angular size; a telescope with a micrometer eyepiece; any other angle-measuring device which assures the required measurement precision. The same method should be used for Galilean telescopes. Key 1 light source 2 condenser 3 f
30、ilter 4 diffusing plate 5 scale 6 collimator lens 7 test specimen 8 optical angle measuring telescope Figure 1 Test arrangement for measurement of the angular magnification BS ISO 14490-1:20053 4.3 Procedure Before starting the measurements, adjust the eyepiece of the test specimen to 0 m 1and focus
31、 the test specimen onto an infinitely remote object. Determine the number of telescope (8 in Figure 1) scale divisions covered by an integral number of collimator scale (5 in Figure 1) image divisions produced by the test specimen. If a telescope with a micrometer eyepiece is used, measure the angul
32、ar size of the image of a part of the collimator scale (5 in Figure 1) produced by the test specimen. 4.4 Determination of results The magnification that is to be found is defined as the ratio of the size of the image of the collimator scale (5 in Figure 1) produced by the telescope to the size of t
33、he corresponding part of the collimator scale. For the case in which a telescope with a micrometer eyepiece is used 1 2 na ma = (2) where n is the number of divisions of the telescope (8 in Figure 1) scale that corresponds to the number of divisions m of the collimator scale (5 in Figure 1) image; a
34、 1is the scale division value of the measuring telescope scale; a 2is the scale division value of the collimator scale. The uncertainty of magnification shall be less than one third of the maximum deviation from the nominal value specified in the relevant specification standard. For calculation of t
35、he magnification difference between the telescopes of a binocular having a magnification of 6 or more, this tolerance shall be reduced by half. 4.5 Test report A test report shall be presented and shall include the general information specified in Clause 13 and the result of the test as specified in
36、 4.4. 5 Method of measurement of the entrance pupil diameter 5.1 General The method of measurement of the entrance pupil diameter D is based on viewing a reticle which is placed near the entrance pupil through the test specimen and reading off the linear size of the entrance pupil diameter. 5.2 Test
37、 arrangement For a schematic representation of the test arrangement see Figure 2. The test arrangement shall be provided with a green optical filter to avoid any chromatism of the image. The maximum transmittance of the filter should be at a wavelength of about 0,55 m. The same method shall be used
38、for Galilean telescopes. BS ISO 14490-1:20054 Key 1 light source 2 condenser 3 filter 4 pinhole 5 collimator lens 6 reticle 7 test specimen 8 intermediate image 9 exit pupil; reticle optional 10 magnifier or microscope 11 scale Figure 2 Test arrangement for the measurement of the entrance pupil diam
39、eter 5.3 Procedure To measure the entrance pupil diameter, set a reticle with a fixed scale (or two adjustable knife edges) immediately in front of the test specimens objective lens. Illuminate the reticle marks (or knife edges) with a collimator. Position a field stop, whose apparent size may not e
40、xceed three arc minutes, in the focal plane of the collimator. Use a microscope or a magnifier behind the eyepiece of the test specimen. Determine which two reticle marks are coincident with the edges of the entrance pupil (or adjust the knife edges to be coincident with the edges of the entrance pu
41、pil). The distance between the reticle marks (or knife edges) coincident with the edges of the entrance pupil is equal to the entrance pupil diameter. 5.4 Determination of results The result is determined by reading off the distance (in mm) between the reticle marks (or knife edges). The distance be
42、tween the reticle marks (or knife edges) in front of the lens can easily be determined with a precision of 0,1 mm. In order to make sure the uncertainty is less than 1 %, a microscope or magnifier of sufficient magnification shall be chosen appropriately for the specimen being tested. 5.5 Test repor
43、t A test report shall be presented and shall include the general information specified in Clause 13 and the result of the test as specified in 5.4. 6 Method of measurement of the exit pupil diameter and eye relief 6.1 General The exit pupil diameter D is defined to be the size of the image of the en
44、trance pupil produced by the test specimen. BS ISO 14490-1:20055 The eye relief l is defined as the distance of the exit pupil from the vertex of the last optical surface of the eyepiece. 6.2 Test arrangement The exit pupil diameter of the test specimen and the eye relief shall be measured with the
45、test arrangement shown in Figure 3. The test arrangement shall be provided with a green optical filter to avoid any chromatism of the image. The maximum transmittance of the filter shall be at a wavelength of about 0,55 m. Key 1 light source 2 condenser 3 filter 4 pinhole 5 collimator lens 6 entranc
46、e pupil 7 test specimen 8 exit pupil; reticle optional 9 measuring microscope Figure 3 Test arrangement for the measurement of the exit pupil diameter and eye relief 6.3 Procedure Before starting the measurements, adjust the eyepiece of the test specimen to 0 m 1and focus the test specimen onto an i
47、nfinitely remote object. To measure the diameter of the exit pupil, focus the measuring microscope onto the exit pupil. Bring the image of the pupil into coincidence with the microscope reticle scale and count the number of scale divisions covering the diameter of the exit pupil image. To measure th
48、e eye relief, focus the measuring microscope first onto the exit pupil, then onto the vertex of the last refracting surface of the test specimen. 6.4 Determination of results Calculate the exit pupil diameter D (in mm) in accordance with the equation D nK = (3) where n is the number of scale divisio
49、ns covering the exit pupil diameter of the test specimen; K is the linear scale division value, in millimetres, of the measuring microscope. BS ISO 14490-1:20056 Determine the eye relief l (in mm) as the difference of readouts from the external scale of the measuring microscope during its axial travel: 121 () laaK = (4) where a 1and a 2are the readouts from the external scale of the
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