Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. इंटरनेट मानक “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “प0रा1 को छोड न’ 5 तरफ” Jawaharlal Nehru “Step Out From the Old to the New” “जान1 का अ+धकार, जी1 का अ+धकार” Mazdoor Kisan Shakti Sangathan “The Right to Information, The Right to Live” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 15485 (2004): Photography - Flash Exposure Meter - Requirements [MED 32: Photographic Equipment]
Transcript
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
इंटरनेट मानक
“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru
“Step Out From the Old to the New”
“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan
“The Right to Information, The Right to Live”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
“Invent a New India Using Knowledge”
है”ह”ह
IS 15485 (2004): Photography - Flash Exposure Meter -Requirements [MED 32: Photographic Equipment]
IS 15485:20041s0 10157:1991
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Indian Standard
PHOTOGRAPHY — FLASH EXPOSURE METER —REQUIREMENTS
Ics 37.040.10
I
,
(3 BIS 2004
I BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
I NEW DELHI 110002Jdy 2004 Price Group 3
Photographic and Cinematographic Equipment Sectional Committee, ME 32
NATIONAL FOREWORD
This Indian Standard which is identical with ISO 10157:1991 ‘Photography — Flash exposure meter— Requirements’ issued by the International Organization for Standardization (ISO) was adopted bythe Bureau of Indian Standards on the recommendations of the Photographic and CinematographicEquipment Sectional Committee and approval of the Mechanical Engineering Division Council.
The text of ISO Standard has been approved as suitable for publication as ah Indian Standard withoutdeviations. Certain conventions are, however, not identical to those used in Indian Standards.Attention is particularly drawn to the following:
a) Wherever the words ‘International standard’ appear referring to this standard, they should beread as ‘Indian Standard’.
b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practiceis to use a point (.) as the decimal marker.
The concerned Technical Committee has reviewed the provisions of ISO 2720:1974, IEC 68-2-6(1960) and IEC 348 (1971) referred in this standard and has decided that it is acceptable for use inconjunction with this standard.
Annex A of this standard is for information only.
IS 15485:20041s0 10157:1991
{ndian Standard
PHOTOGRAPHY — FLASH EXPOSURE METER —REQUIREMENTS
1 Scope
This International Standard applies to photoelectricflash exposure meters which measure the time in-tegral of the luminance or of the illuminance of aphotographic object (to be called thereafter“object”) illuminated by a source of light for a briefillumination periodlJ and indicate the time integralor a number corresponding to the time integral orthe J-number required for the correct exposure of aphotographic film with a given speed.
Continuous light, which is available in addition to thelight emitted by the flash light source, is also evalu-ated.
NOTE 1 If the object is illuminated by electronic flashequipment with automatic exposure control, the measur-ing results of the flash exposure meter can deviate fromthe calibration values of the flash equipment.
2 Normative references
The following standards contain provisions which,through reference in this text, constitute provisionsof this International Standard. At the time of publi-cation, the editions indicated were valid, All stan-dards are subject to revision, and parties toagreements based on this International Standardare encouraged to investigate the possibility of ap-plying the most recent editions of the standards in-dicated below. Members of IEC and ISO maintainregisters of currently valid International. Standards,
ISO 2720:1974, Photography – General purposephotographic exposure meters (photoelectric type)– Guide to product specification,
IEC 68-2-6:1960, Basic environments/ testing pro-cedures for electrical components and electronicequipment – Part 2: Tests — Test F: Vibration.
IEC 348:1971, Safetymeasuring apparatus.
3 Definitions
requirements for electronic
For the purposes of this International Standard, thefollowing definitions apply.
3,1 luminance coefficient, q: The luminance coef-ficient, q, is the ratio of the luminance, L, of thesample for a given observation direction to theilluminance, IL on the sample (q= /,/E).
3.2 gate time: The gate time of the measuring cir-cuit is the time in which the flash light meter ismeasuring.
3.3 storage time: The storage time is that time afterthe end of the gate time in which the indicated valuechanges by +-7 “A [corresponding to ~ 1I1O ~z)].
3.4 acceptance angle: See definition in ISO 2720.
4 Scales
Relative aperture scale, exposure time scale andfilm speed scale are to be selected in accordancewith ISO 2720.
5 General characteristic quantities of theflash exposure meter
5.1 Measuring range
It is recommended that the measuring range be in-dicated in candela seconds per square metre whenmeasuring the time integral of luminance of the ob-ject and in Iux seconds when measuring the timeintegral of illuminance of the object.
In addition, the aperture range and the luminoustime (flash duration) range a~e to be indicated, in
1) ,Nithin the range of gate time specified by the manufacturer for the specific meter.
2) R= Exposurevalue.
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which a measurement of flash light at an ISO 100/21° 6 Callbratlonfilm speed is possible,
5.2 Gate time 6.1 Measuring method
During the gate time both the light of the flash lightsource and the light of the surroundings (continuouslight) are to be measured. It is recommended thatthe times of the exposure time scale be used in ac-cordance with ISO 2720. If there is only one fixedgate time, it must not be less than 0,00781 s and isto be indicated. If the flash exposure meter does not,or does not completely, evaluate continuous light,this fact is also to be indicated.
5.3 Storage time
If the meter incorporates an automatic switching-offcircuit, the storage time shall be long enough so thatthe meter indication can be read. The storage timeshall be indicated on the exposure meter or in theinstruction booklet.
5.4 Addition of individual measurements
If the measuring values of individual measurementsare or can be added with the flash exposure meter,the deviation from the sum of four single flashes(provided there is a constant radiation from the ffashlight source) must not be greater than l/5FW.
For calibration or for checking the calibration, knownexposures are produced and compared with the in-dication of the flash exposure meter when measur-ing the iight at the same piace as the acceptancedevice of the flash exposure meter,
6.2 Light source
The calibration of flash exposure meters is to bechecked with a iight source of the correlated colourtemperature of 5500 K + 200 K. it must be possibieto set the duration of the light source, one-tenth ofthe time vaiue, to between 0,8 x 10–2 s and1.0 x 10-4 s.
6.3 Measuring the light which falls upon theobject
5.5 Acceptance angle or
(Measuring the object exposure.)
(Measuring the incident light.)
Calibration formula
!{= f~dt=~
The acceptance angies are measured in accordancewith ISO 2720.
5.6 Spectral response
H= ~Edt= ;A2,.(s - 1)/10
where
H is the exposure of the object, in IUX sec-The spectrai response of the photoelectric receiver ends;shali show no discontinuities within the visiblespectrum (380 nm to 780 rim). JEdt is the time in~egral of iiiuminance, E, in
iux;The ratio of the indications of the receiver, inciudingopticai eiements, for a luminance of the distributiontemperature of 4700 K compared with that of the CiEstandard iiluminant C (representing dayiight with aco~~e~ated colour temperature of 6774 K), shall be1 –O:pl (corresponding to + l/3EJ. Not more than10 % of the total response of the receiver, inciudingopticai systems, should be due to wavelengthslonger than 700 nm when the receiver is exposed tolight sources of equai energy at all wavelengths, Notmore than 10 0/0 of the totai response of the receivershouid be due to wavelengths shorter than 380 nmwhen tested in the same manner,
A Is the }numbe.fl
s is the arithmetic ISO fiim speed;
so is the logarithmic ISO fiim speed;
C is a constant which can be seiected bythe manufacturer in the range of 210 ix.sto 420 Ix.s for the given type of exposuremeter.
NOTE3 The reflectance of the object, which is con-sidered to be a uniform diffuser, is assumed to be 0,18.
NOTE 2 A light source with a distribution temperature If a reflected-light type flash exposure meter is to beof 4700 K is specified in ISO 2720. The CIE standard designed, the calibration constant ((7) can be deter-source C is specified in CIE Publication No. 15, mined by using the reflectance of the object.
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7 Measuring accuracy
7.1 Error iimltsof theindlcation
The combined effect of calibration temperature, hu-midity, storage condition, exposure, vibration ex-posure, shock exposure, position, and flash durationshall not cause the indication to varv bv more than
~ ~ 3/4/?-?-from the nominal value. ‘ ‘
7.2 Flash duration and Hluminance
Within the time range between 8 x 10–3 s and10-4 s and the il!uminance range between 5 x 102 lxand 2 x 106 lx, the meter shall give the same indi-cation with a tolerance of + l/3& for the sameamount of the time integral of illuminance.
8 Influence of external measuringconditions
8.1 Temperature range
The values indicated by the flash exposure meter,at temperatures of between O ‘C and 40 ‘C, com-bined with other effects, must not differ by more thanthe tolerance given in 7.1 from the values of thecalibration formulae in 6.2 and 6.3.
8.2 Effect of humidity
The influence of the humidity is expressed as amodification of the exposure indication at 40 ‘Cf 5 “C and (90 + 5) ‘A relative humidity. Followingthe exposure to high humidity for 48 h and prior toIaking measurements, the ffash exposure metershall be stored for 2 h at 23 ‘C I 3 “C and(65 t 20) % relative humidity. The modification ofthe climate must be carried out slowly so that thedew point is not reached.
9 Mechanical strength
Requirements and testing shall be in accordancewith IEC 348.
9.1 Requirements
The apparatus shall have adequate mechanicalstrength. The components shall be reliably fastenedand secured. The electrical connections shall be re-liable. Internal wiring shall be installed in such amanner that its insulation cannot be damaged.
These requirements should be especially con-sidered for apparatus containing sources of vi-bration or shock, and safety measures should betaken against influences on other assemblies.
Compliance is checked by inspection and by per-forming the following tests,
The tests described in 9.2 and 9,3 shall be performedon portable apparatus. For other apparatus, thesetests are recommended but are optional.
The tests are ‘based on the assumption that labora-tory or industrial use of the apparatus causes noabnormal stress. These tests may not be sufficientfor apparatus such as that used in vehicles.
9.2 Fail test
The apparatus shall be fixed in its position of normaluse to a hardwood board and shall be dropped flatlythree times on to a hardwood plate having a massof at least three times the falling mass. The testset-up shall be in accordance with IEC 348:1971, tig-ure 5, and the drop heiaht shall be in accordancewith table 1 of this lntern~tional Standard.
Table 1 – Drop height
Falling mass Drop height
kg cm
EzL--LL9.3 Vibration test
Apparatus shall be subjected to vibration enduranceconditioning by frequency sweeping as specified inIEC 68-2-6.
The apparatus is fastened in its normal position ofuse to the vibration generator by means of strapsaround the enclosure. The direction of vibration isvertical, and the conditions are as follows:
Duration:
Amplitude (peak-to-peak):
Sweep frequency range:
Sweep rate:
30 min
0,35 mm
lo Hz–55Hz–10 Hz
Approximately oneoctave per minute
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9.4 Blow test IEC 348:1971, figure 6. The hammer shall be appliedto any external part that, when broken, is likely to
The apparatus is held firmly against a rigid support expose live parts, including handles, levers, knobs,and shall be subjected to sets of three blows from and the like, by pressing the hammer nosea spring-operated impact hammer as shown in perpendicularly to the surface of that part.
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II [1]
[2]
IS 15485:2004
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Annex A(informative)
Bibliography
ISO 1230:1973, Photography – Determination [3]of flash guide numbers.
ISO 2721:1982, Photography – Cameras –Automatic controls of exposure. [4]
[5]
ISO 2827:1988, Photography – Electronic flashequipment — Determination of light output andperformance.
ISO 5763:1989, Photography – Electronic flashequipment — Automatic control of exposure.
CIE Publication No.15:1971, Coiorimatry.
T-’
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edition by referring to the latest issue of ‘BIS Catalogue’ and ‘Standards: Monthly Additions’.
This Indian Standard has been developed from Doo: No. MED 32 (704).
Amendments Issued Since Publication
Amend No. Date of Issue Text Affected
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