BS ISO 516 pdf free download

BS ISO 516-2019 pdf free download.Photography — Camera shutters — Timing.
6 Test methods
6.1 General The method described for each type of shutter, based on digital readout, is rapid and easy for routine manufacturing testing and quality control. As a rule, this method is applicable only to cases in which the character of the time-illuminance curve of the shutter has been proved consistent and acceptable by graphic methods such as those described in Annex A.
6.2 Apparatus
6.2.1 Light source The light source shall consist of a lamp and a diffuser. Luminance at any point on the surface of the diffuser, measured perpendicular to the surface, shall be more than 95 % of the maximum luminance and the fluctuation of luminance shall not exceed ± 5 %. Luminance of the diffuser, measured at any angle to the diffuser up to 60° from the normal, shall not be less than 85 % of the luminance measured perpendicular to the surface.
6.2.2 Detector The frequency response of the combination of detector, cables and recording equipment shall be within ± 3 dB from D.C. to 100/t o : for example for a total time of 1 ms, the frequency response shall be at least 100 kHz (50 % output power, i.e. 70 % output voltage, with sinusoidal input). This combination shall have a linear sensitivity characteristic between 1 % and 100 % of E o . The sensitive area of the detector shall be large enough to receive all the light passing through the entrance aperture. (See Figure 4.)
6.2.3 Time-interval meter A meter shall have an internal time base, a selection of ranges and an adjustable sensitivity. The frequency of the time base shall be sufficiently high for at least 100 samples to be taken during the minimum effective time to be measured.
6.3 Front-shutter test
6.3.1 Test assembly The test assembly is shown in Figure 4. The fully opened standard lens shall be used as a taking lens.
6.3.2 Procedure Pass a uniform light bundle through the shutter and into the detector (6.2.2) whose output is used to control the time-interval meter (6.2.3). Adjust the sensitivity of the meter to start and stop measurement when the detector output is at the level corresponding to the time (t o or t e ) measured as in 6.3.2.1 and 6.3.2.2.
6.3.2.1 Total time, t o
Adjust the light intensity and meter sensitivity so that gating occurs at 1 % ± 0,5 % E o .
6.3.2.2 Effective time, t e
Adjust the light intensity and meter sensitivity so that gating occurs at the fraction of E o that yields a time measurement, which is identical to effective time.
Determine the fraction as follows:
a) determine t o and t e as in clause A.3 of Annex A;
b) read the height (E) above the baseline at which the rising and falling positions of the curve are separated by t e ;
c) the height (E) divided by E o is the fraction of illuminance at which the time measurement is started and stopped.
NOTE 1 If the trace is trapezoidal, t e can be measured at 0,5 E o .
NOTE 2 For front shutters, effective time varies with the aperture of the lens. Therefore, the fully opened lens shall be used for the measurement.
NOTE 3 For programmed shutters, effective time shall be measured at the aperture determined by the programming of the shutter.BS ISO 516 pdf download.