How International Standards affect Camera Testing October 2008 1
In the beginning When I started testing cameras in 1997 I sat there and asked myself: how the hell shall I do that? 2
The unlimited number of standards Isn t there a standard method how to test cameras? There are several: ISO 12231: Terminology ISO 12232: Determination of ISO speed ISO 12233: Resolution measurements ISO 12234: Removable memory Part 1: Basic removable memory reference model Part 2: data format - TIFF/EP ISO 14524: Methods for measuring opto-electronic conversion functions (OECF) ISO 15739: Noise measurements ISO 15740: Picture Transfer Protocol (PTP) for Digital Still Photography Devices 3
The unlimited number of standards ISO 15781: Measuring shooting time lag, shutter release time lag, shooting rate, and start-up time ISO 17321: Graphic technology and photography Colour characterisation of digital still cameras Part 1: Stimuli, metrology, and test procedures ISO 20462: Psychophysical experimental method to estimate image quality Part 1: Overview of psychophysical elements Part 2: Triplet comparison method Part 3: Quality ruler method ISO 22028 Extended colour encodings for digital image storage, manipulation and interchange Part 1: Architecture and requirements Part 2: ROMM RGB Part 3: RIMM RGB Part 4: ECI RGB 4
The unlimited number of standards Standardisation committees: International Organization for Standardization (ISO) Technical Commitee (TC) 42, Working Group 18 Cell Phone Quality Group organized by International Imaging Industry Association (I3A) International Electrotechnical Commission (IEC) Technical Commitee (TC) 100 Related Organisations: ICC, CIE, SMPTE 5
Values which can be measured: Resolution (s) Dynamic Range (s) Used digital values (s) Noise (s) Color Reproduction (s) White Balance (s) Vignetting (s) Distortion (s) Power consumption Dead Pixels 6
Values which can be measured: Max. scaling Flash uniformity and guide number Lateral chromatic aberration (s) Color shading Noise based on human perception (s?) Shutter and shooting lag (s?) Startup time and shooting rate (s?) stabilization (s?) 7
Principle 8
Principle 9
Standards are not God given Several problems occured 10
Standards are not God given Several problems occured 11
resolution measurement 12
Finding new methods Signal to noise vs. Visual noise SNx= 27 SNx= 29 13
color reproduction quality 14
color reproduction quality 15
color reproduction quality 16
shutter and shooting lag 17
Welcome: Steve ( Stabilizer Evaluation Equipment ) 18
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OECF, Speed, and Noise (ISO 14524, 15739) 20
OECF, Speed, and Noise (ISO 14524, 15739) 21
vignetting / corner shading 22
vignetting / corner shading 23
distortion 24
chromatic aberration 25
power consumption test 26
power consumption and shooting rate 30 25 20 15 Reihe1 10 5 0 0 5000 10000 15000 20000 25000-5 25 Reihe1 Reihe2 20 15 10 5 0 900 1400 1900 2400 2900 27
max. scale 28
Flash: uniformity and guide number Ze ile 1,00 0,90 0,80 0,90-1,00 0,70 y 11 42 93 132 Log Lum inanz 1,08 1,97 2,97 0,80-0,90 0,70-0,80 0,60 0,60-0,70 0,50 0,50-0,60 0,40 0,40-0,50 0,30-0,40 0,30 0,20-0,30 0,20 0,10-0,20 0,10 R25 0,00-0,10 R17 40 R1 37 31 34 25 28 22 19 13 R9 16 7 10 1 4 0,00 Log Lum inanz 3 0,67 4 1,46 5 1,92 6 2,16 Differenz Ble nde ns tufen 29
resolution measurement 30
resolution measurement 31
resolution measurement 32
Measuring spectral sensitivities 33
Measuring spectral sensitivities Nikon D70 spectral response 1,2 rel. spectral response 1,0 R_IF G_IF B_IF R_LED G_LED B_LED R_mono G_mono B_mono 0,8 0,6 0,4 0,2 0,0 350 400 450 500 550 600 650 700 750 wavelength [nm] 34