ISO INTERNATIONAL STANDARD 13653 Second edition 2019-05 Optics and photonics General optical test methods Measurement of relative irradiance in the image field Optique et photonique - Methodes génerales d'essai optique - Méthode de mesure de I'éclairement énergetique relatif dans le champimage Reference number IS013653:2019(E) osi @ IS0 2019 IS0 13653:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 13653:2019(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms and definitions 4 Quantities, symbols and units ..2 5 Designation ..2 6 Description of measurement procedures ..3 6.1 Factors influencing the relative irradiance .3 6.1.1 General .3 6.1.2 Natural fall-off in brightness, Fnat = cos4wp (cos4 law) 3 6.1.3 Relative pupil surface, Fp(wp) .3 6.1.4 Vignetting, Fvig(wp) 3 6.1.5 Influence of the transmission, Fr(wp) .3 6.1.6 Change in size of the image surface element due to distortion. 3 6.1.7 Resultingrelativeirradiance .4 6.2 Classification of the measurement procedures 4 6.3 Brief description of the irradiance measurement ..4 6.4 Brief description of the radiant power measurement .4 7 Measurement of relative irradiance .5 7.1 Description of the measuring set-up .5 7.1.1 Source of radiation. .5 7.1.2 Test specimen holder. 5 7.1.3 Measuring system 5 7.2 Measurement.. ..6 7.2.1 Adjustment of the measuring set-up .6 7.2.2 Spectral region. .6 7.2.3 Determination of measurement value ..6 7.2.4 Selection of image heights and image-space pupil field angles 7 8 Measurement of radiant power .7 8.1 Description of the measuring set-up .7 8.1.1 Source of radiation.. 7 8.1.2 Adjusting elements .7 8.1.3 Measuring system .8 8.2 Measurement. .8 8.2.1 Adjustment of the measuring set-up .8 8.2.2 Spectral region. .9 8.2.3 Determination of the measurement value .9 8.2.4 Selection of the object-space pupil field angles ..9 6 Presentation of results .9 9.1 Tabular form 9.2 Graphical representation .10 9.2.1 Curvesofmeasuredvalues .10 9.2.2 Curvesofegualrelativeirradiance ..10 10 Test report ..10 11 Examples. ..11 11.1 Measurement of relative irradiance by procedure A1 (see Figure 4, Table 4) 11 11.2 Example of the representation of curves of equal relative irradiance against the image field (see Figure 5) 11 @ IS0 2019 - All rights reserved ii