ISO-7829-1986.pdf

INTERNATIONAL STANDARD IS0 7829:1986 TECHNICAL CORRIGENDUM 1 Published 2001 -06-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MM(CIYHAPOflW OPrAHM3Ai44FI iì0 C T W M W H H ORGANISATION INTERNATIONALE DE NORMAUSATION Photography - Black-and-white aerial camera films - Determination of IS0 speed and average gradient TECHNICAL CORRIGENDUM 1 Photographie - Films noir et blanc pour photographie aérienne - Détermination de la sensibilité et du contraste moyen IS0 “A viation“ RECTIFICATIF TECHNIQUE 1 Technical Corrigendum 1 to International Standard IS0 7829:1986 was prepared by Technical Committee I SO/TC 42, Photography. Page 2, clause 5 In the second footnote to Table 1, replace “2 854 K“ with “2 856 K“. Page 3, subclause 5.5 Delete the last two sentences beginning “A minimum aperture .“ and ending “ the exposures. “ and replace with “Readings shall be made in a uniform area of the image, typically at least 1 mm from the edges of the exposures.“ ICs 37.040.20 8 IS0 2001 -All rights reserved Printed in Switzerland Ref. No. IS0 7829:1986/Cor.l:2001(E) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/23/2007 22:44:20 MDTNo reproduction or networking permitted without license from IHS -,-,- International Standard 7829 INTERNATIONAL ORGANIZATION FOR STANOARDIZATIONaMEYHAPOAHAR OPrAHH3AUMR fl0 CTAHAAPTM3AUHMaORGANISATiON INTERNATIONALE DE NORMALISATION Photography - Black-and-white aerial camera films - Determination of IS0 speed and average gradient Photographie - Films noir et blanc pour photographie aérienne - Détermination de la sensibilité et du contraste moyen IS0 (Aviations First edition .- 1986-08-15 UDC n1.m.a : n a . = Ref. No. IS0 7829-1986 (E) Descriptors : photography, aerial photography, black-and-white photography, photographic film, roll films, tests, determination, sensitivity (photography). Price based on 9 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/23/2007 22:44:20 MDTNo reproduction or networking permitted without license from IHS -,-,- I 4851703 0057765 T r Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 7829 was prepared by Technical Committee ISO/TC 42, Photography. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. O International Organization for Standardization, 1986 0 Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/23/2007 22:44:20 MDTNo reproduction or networking permitted without license from IHS -,-,- 7829-86 1 4 8 5 3 9 0 3 DO57966 1 r INTERNATIONAL STANDARD IS0 7829-1986 (E) Photography - Black-and-white aerial camera films - Determination of IS0 speed and average gradient O Introduction IS0 was requested to develop a method for measuring speed and average gradient of black-and-white negative camera film- process combinations used in aerial photography because of the incompatability of various existing standards; the aim being to create an International Standard that would incorporate the most important features of these standards. . Changes in aerial photography over the last IOyears, par- ticularly those related to the increased use of mechanized pro- cessing, has made it necessary to eliminate the processing restrictions present in some of the existing standards in order to provide the user with realistic IS0 speed and average gradient values. Assigning speed values to aerial films presents problems. Aerial films are required to record or even amplify the small variations in luminance that exist when the earth is viewed from altitudes of several kilometres or as low as 20 to 30 m where the luminance range may be of the same order as that of ordinary ground photography. In the first case, the films are developed to a high average gradient or contrast; and in the second case, to a very low average gradient. In addition to the factor of elevation (slant range), the luminance range of the subject mat- ter may be further modified by aerial haze, solar altitude, and contrast (ratio of sunlight to skylight). Modifying the process- ing of a given aerial film, or the selection of film emulsions hav- ing certain preferred gradation characteristics, are methods commonly used for obtaining optimum information. In recognition of these factors, this International Standard does not specify the processing conditions, but provides a method for measuring the speed of various film-process combinations; this means that a description of both the film and process used shall be given when quoting IS0 speed values. Therefore, a single film product may have several speed values associated with it depending not only on the extent of development in a particular process, but also on the type of developer, machine, etc., used. The density at which the speed is calculated is 0,30 above base plus fog which is considered a compromise b e tween minimizing the influence of contrast variations on speed and the minimum density to which aerial films are exposed. A method for determining the IS0 aerial average gradient is also described in this International Standard. Since IS0 aerial speed is dependent on the extent of development, it is sug- gested the IS0 average gradient values be provided whenever IS0 speed is given, for example, IS0 A640/G 1.6. It should however, be recognized that other characteristics such as fog, image quality, etc. may also be affected by the extent of development. 1 Scope and field of application This International Standard specifies the method for determin- ing the IS0 aerial speed and IS0 aerial average gradient of black-and-white negative camera film-process combinations used in aerial photography. Since there is no ideal, “gamma“, “average gradient“, or any other characteristics that can be ascribed to an aerial film for all applications, no single contrast or degree of development as a measure of film contrast is specified in this International Stan- dard for determining film speed. Therefore, it is possible for a film to have several speed and average gradient values assigned to it depending on the processing conditions. This International Standard does not apply to infrared aerial films. “ 2 References IS0 5, Photoclraahv - Densitv measurements I At the present time, there are a number of processing methods that can be used for aerial films. Some of them are difficult to define or may not be representative of all conditions under - Part 2 : Geometric conditions for transmission density. - Part 3 : Spectral conditions. which aerial films will be processed. Most standards for deter- mining the speed of aerial films specify a single process for determining speed, but the values obtained are of limited use and are seldom used due to lack of correlation with practical applications. IS0 554, Standard atmospheres for conditioning and/or testing - Specifications. CIE Publication No. 15 (E-1.3.1.) 1971, Colorimetry. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/23/2007 22:44:20 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7829-1986 (E) 1 4 8 5 1 9 0 3 0057967 3 3 Definitions For the purpose of this International Standard the following definitions apply. 3.1 exposure, H : The time integral of illuminance on the film measured in lux seconds and designated by the symbol H. NOTE - Exposure is often expressed in logloH units. 3.2 speed : A quantitative measure of the response of the photographic film-process combination to radiant energy for the specified conditions of exposure, processing, and image measurement. 3.3 two points on a sensitometric curve. average gradient : The slope of the straight line joining 4 Sampling and storage In determining the IS0 speed of a product, it is important that the samples evaluated yield the average results obtained by users. This will require evaluating several different batches periodically under the conditions specified in this International Standard. Prior to evaluation, the samples shall be stored ac- cording to the manufacturers' recommendations for a length of time to simulate the average age at which the product is nor- mally used. Several independent evaluations shall be made to ensure the proper calibration of equipment and processes. The basic objective in selecting and storing samples as described above is to ensure the film characteristics are representative of those obtained by a photographer at the time of use. 5 Method of test 5.1 Principle Samples are exposed and processed as specified below. Den- sity measurements are obtained from the resultant image to produce a sensitometric curve from which values are taken and used to determine IS0 aerial speed and IS0 aerial average gradient values. 5.2 Safelights To eliminate the possibility of safelight illumination affecting the sensitometric results, all films shall be handled in complete darkness during exposing and processing. 5.3 Exposure 5.3.1 Sample condition During exposure, the samples shall be at a temperature of 23 f 2OC and a relative humidity of 50 _+ 5 %. This is the recommended atmosphere and normal tolerances specified in IS0 554 for test results. 5.3.2 Type of sensitometer The sensitometer shall be a non-intermittent, illuminance-scale WPe. 5.3.3 Radiant energy quality 5.3.3.1 Relative spectral power distribution The relative spectral power distribution of the illuminant shall be as specified in table 1. These values were derived by multiplying the relative spectral power distribution values for D , by the transmittance values, T, of an IS0 standard aerial camera lens. 5.3.3.2 Filters IS0 speed shall be specified for use without a filter in front of the camera lens. If film is used with a colour filter in front of the camera lens, an “equivalent“ speed number can be used to Table 1 - Relative spectral power distribution of IS0 sensitometric aerial daylight Relative spectral daylight power distribution Relative lens International standard sensitometric of aerial photographic transmittance aerial photographic daylight illuminant Wavelength, A Tolerances ínm) D , * 5 350 35 O O oto +2 400 7 1 26 18 16to 22 450 106 70 74 69to 83 500 103 69 92 85 to 103 550 1 02 98 100 O 600 90 99 89 83 to 98 650 82 99 81 74 to 90 700 75 98 74 67 to 82 750 66 96 63 58 to 71 This is the CIE Standard illuminant representing a phase of daylight with a correlated colour temperature of 6 003 K normalized to 102 at 550 nm. * This relative power distribution may be approximated by the use of a 2 854 K tungsten source, an appropriate daylight conversion filter (for example Corning filter 5900 or equivalent) and a heat absorbing filter. Relative“ power b 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/23/2007 22:44:20 MDTNo reproduction or networking permitted without license from IHS -,-,- 7827-86 q85L703 0057768 5 determine the exposure of the film with the filter. IS0 speed does not apply to the filtered condition. 5.3.4 Modulation The total range of spectral diffuse transmission density with respect to the film plane of each area of the light modulator throughout the wavelength interval from O to 750 nm, shall not exceed 5 % of the average density obtained over the same interval or 0 , 0 3 density, whichever is greater. In the interval from 360 to 400 nm, 10 % of this same average density, or 0,06 density, whichever is greater, is acceptable. If stepped increments are used, the exposure increment shall not be greater than 0,20 logloH units per step. The width and length of a single step shall be adequate to obtain a uniform density, devoid of edge effects, within the minimum reading aperture specified for densitometry. If continuous variable modulation is used, the change in ex- posure with distance along the test strip shall be uniform and not be greater than 0,04, logloH units per millimetre. 5.3.5 Exposure time The exposure time shall correspond with the usage practice for the particular film tested. Since the speed of film is dependent on the exposure time because of reciprocity law failure effects, the exposure time used for determining IS0 speed and average gradient shall be specified in the use instructions. An area of the film shall not be exposed, to produce the minimurn density possible. 5.4 Processing 5.4.1 Conditioning of samples In the time interval between exposure and processing, the samples shall be kept at 23 f 2 O C and a relative humidity of 50 5 5 %. The processing shall be started between 1 h and 2 h after exposure. 5.4.2 Processing specifications No processing specifications are described in this International Standard, in recognition of the wide range of chemicals and equipment used. IS0 aerial speed and average gradient values provided by film manufacturers generally apply to the film when it is processed in accordance with their recommendations to produce the photographic characteristics specified for the process. Process information shall be available from the film manufacturers or others who quote IS0 speed and IS0 average gradient values. This shall specify the chemicals, times, temperatures, agitation, equipment and procedure used for each of the processing steps, and any additional information re- quired to obtain the sensitometric results described. The values for speed and average gradient obtained using various processing procedures may differ significantly. Although different speeds and average gradients for a par- ticular film may be achi