WP1 – Goniochromatism - xD Reflect · Höpe/Strothkämper xD-Reflect, 4th Project Meeting, Alicante, Spain page 2 of 68 • Short information about PTB • Infrastructure of WG

Dr. Andreas Höpe, Dr. Christian Strothkämper Physikalisch-Technische Bundesanstalt WG 4.24 “Reflection and Transmission“ Bundesallee 100 38116 Braunschweig

WP1 – Goniochromatism Progress report

04.12.14

xD-Reflect 4th Project Meeting, Alicante, Spain

page 2 of 68 Höpe/Strothkämper xD-Reflect, 4th Project Meeting, Alicante, Spain

• Short information about PTB

• Infrastructure of WG 4.24

• WP1 “Goniochromatism“

- Review of tasks up to now

Overview


Werner-von-Siemens Building in Berlin

● is working at the locations Braunschweig and Berlin ● is one of the oldest NMIs worldwide,

it was founded as PTR in 1887 ● is one of the biggest Metrology Institutes

worldwide, it engaged about 1950 staff members (2013)

● is the main important national service provider in the measurement business in Germany

● has an annual budget of about 185 Mio € (2013)

● is the highest technical authority under the auspices of the Federal Ministry of Economics and Technology (BMWi)

PTB ... (in short)

PTB main entrance in Braunschweig


PTB ... (Organigram overview)

Mechanics and Acustics

Electricity

Chemical Physics and Explosion Protection

Optics

Precision Engeneering

Ionising Radiation

Temperature and Synchrotron Radiation

Medical Physics and Metrological Information Technology

Scientific-technical Cross-sectional Tasks

Administrative Services

Berlin


PTB, at the sites of Braunschweig and Berlin

● Location of the sites of PTB in Braunschweig and Berlin in the northern part of Germany

230 km

Braunschweig

Berlin Charlottenburg, historic site

Berlin, Adlershof (BESSY, MLS)


PTB ... (Divisions in Braunschweig)

PTB-Braunschweig PTB-Braunschweig PTB-Braunschweig

Area of approx. 1 km2

Albert-Einstein building

● 1. Mechanics and Acoustics ● 2. Electricity ● 3. Chemical Physics and Explosion Protection ● 4. Optics ● 5. Precision Engineering ● 6. Ionising Radiation ● Q. Scientific-technical ● Cross-sectional Tasks ● Z. Administrative Services (approx. 1500 staff members in Braunschweig)


PTB ... (Division 4. “Optics“)


WG 4.24 “Reflection and Transmission“

Customers for calibrations ● Other NMIs without own absolute diffuse

reflection scale ● Paper, textile and colour industry ● Enterprises with radiometric and

photometric product line-up - Manufacturer of spectrophotometers, colorimeters ● Automotive industry ● Research institutes - Measurements for radiometric calibrations of instruments for remote sensing satellites - Appearance measurements of effect pigments


WG 4.24 “Reflection and Transmission“

Realisation, maintenance and dissimination of the scales of diffuse reflection,

Standardising laboratory of the ISO

● Measurement of the (absolute) spectral radiance factor, for:

- Sphere geometries (d:0° – d:10°), λ = 250 nm – 2450 nm

- Bidirectional geometries with robot-based gonioreflectometer (realisation of arbitrary incident and reflection angles), λ = 250 nm – 1850 nm


Robot-based Gonioreflectometry (1)

(2) (3) (4) (5)

Ideal for the measurement of extraordinary formed objects, such as: (1) Test block for safety systems for high rack stacker systems (2) Calibration standard (grey standard) for „Multispectral Image

Processing“ (3) Standard for the calibration of earth observation sensors on

satellites (4) Paper sheet with printed effect pigments (5) Elektrode housing for LISA Pathfinder satellite mission


Robot-based Gonioreflectometry

● Standard robot-based gonioreflectometer (since 2004)

- calibrations with respect to the radiance factor /BRDF - calibration of reflection standards

● ARGon3: 3D Appearance Robot-based Gonioreflectometer - Determination of colour coordinates - spatially resolved measurements of luminance and luminance factor


Robot-based Gonioreflectometry ● Regarding xD-Reflect: - Measurement/calibration of the samples for the

comparison “Traceability of instruments”

● Regarding xD-Reflect: - Measurement of the goniochromatic, sparkling

samples in 114 geometrical configurations - Determination of colour coordinates


xD-Reflect WP1: “Goniochromatism“


WP1: Conference contributions

"Multidimensional Reflectometry for Industry" (xD-Reflect) an European research project Paper 9018-3:

Conference 9018 Measuring, Modeling, and Reproducing Material Appearance

2. – 6. February 2014 San Francisco, California, USA

24. – 27. June 2014 Espoo, Finland

xD-Reflect "Multidimensional Reflectometry for Industry“ a research project of the European Metrology Research Program (EMRP)



German Society of Color Science and Application




xD-Reflect: Publications

A. Höpe, A. Koo, F.M. Verdu, F.B. Leloup, G. Obein, et al. "Multidimensional reflectometry for industry" (xD-Reflect) an European research project, Proc. SPIE 9018, Measuring, Modeling, and Reproducing Material Appearance, doi:10.1117/12.2035981, http://dx.doi.org/10.1117/12.2035981, SPIE-IS&T/ Vol. 9018, p. 901804-1 - 901804-11 (2014)


xD-Reflect: Publications

OT_PO_006 “Virtual experiment uncertainty analysis of robot-based gonioreflectometers” A. Höpe, C. Forthmann, K.-O. Hauer, M. Langovoy, F. Schmähling, G. Wübbeler

24. – 27. June 2014 Espoo, Finland


xD-Reflect: WP1 “Goniochromatism“

Webseite: www.xdreflect.eu


xD-Reflect: Web page WP1 Goniochromatism

Webseite: www.xdreflect.eu


WP1: Goniochromatism •Enhance the spectral and spatial resolution of reference gonioreflectometers developed by each participant, using modern detectors, conoscopic optical designs, CCD cameras, line scan camera, modern light sources

Architecture Printing




(PTB, CNAM, CMI, CSIC, INRIM, MIKES, MSL, SP, UA)

Task 1.1: Improvement of the traceability for standard goniometric geometries

Task 1.2: Extensive study of existing standard materials (multi-geometry, extended wavelength)

Task 1.3: Identification of a basic set of parameters for goniometric effects

Task 1.4: Data handling recommendation for goniochromatic materials

Task 1.5: Database for impact work package (multi-geometry, wavelength dependent)


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Deliverable Leader 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37D1.1.1 PTBD1.1.2 PTBD1.1.3 PTBD1.1.4 PTBD1.1.5 PTBD1.1.6 PTBD1.1.7 PTBD1.1.8 PTBD1.1.9 PTBD1.1.10 PTBD1.1.11 REG(UA)D.1.1.12 PTBD1.2.1 PTBD1.2.2 PTBD.1.2.3 CSICD.1.2.4 CSICD1.2.5 PTBD1.2.6 CSICD1.2.7 PTBD1.2.8 PTBD1.3.1 PTBD1.3.2 PTBD1.3.3 REG(UA)D1.3.4 REG(UA)D1.3.5 CSICD1.4.1 CSICD1.4.2 CSICD1.4.3 PTBD1.4.4 REG(UA)D.1.5.1 PTBD1.5.2 REG(UA)D1.5.3 REG(UA)

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Del. No. Deliverable description Delivery date

Status and activity

1.1.1 Two sets of diffuse matt ceramic grey scale standards, containing three different reflectances of 88 % white, 40 % grey and 5 % deep grey

nov-13

On time, no technical issue. The Physikalisch-Technische Bundesanstalt (PTB) ordered three sets of ceramic grey-scale tiles with nominal reflectances of 88% (white), 40% (grey) and 5% (deep grey) from the company CERAM (United Kingdom), which also a collaborator of the xD-Reflect project. This total amount of nine ceramic tiles was ordered as bare ceramic disks without any mounting. In the machine shop of PTB precision aluminium mounts with transparent acrylic glass covers were manufactured. The ceramic grey-scale tiles were than aligned and mounted into these aluminium mount containers. On the backside of every sample container a distinctive numbering (EMRP xD-11, EMRP xD-21, etc.) and a line mark for maintaining the orientation during the calibration was engraved.

1.1.5 Selection, purchasing and preparation of two sets of diffuse matt ceramic colour standards, containing three different colours, namely red, green and blue nov-13

On time, no technical issue. The Physikalisch-Technische Bundesanstalt (PTB) initiated an internal study about reasonable colours and possible colour standards for the interlaboratory comparison. The outcome of this study was the decision to select three colour standards with the designation of red, green and deep blue with matt surface finish from the company CERAM (United Kingdom), which also a collaborator of the xD-Reflect project. This total amount of nine coloured ceramic tiles was ordered as bare ceramic disks without any mounting. In the machine shop of PTB precision aluminium mounts with transparent acrylic glass covers were manufactured. The coloured matt ceramic tiles were than aligned and mounted into these aluminium mount containers. On the backside of every sample container a distinctive numbering (EMRP xD-14, EMRP xD-24, etc.) and a line mark for maintaining the orientation during the calibration was engraved.


88 % white

UV 254 nm

UV 365 nm

formerly

xD-Reflect: Traceability of instruments



The different sets of grey scale and color standards in their transport cases




Status and activity

1.1.2 Calibration of the spectral radiance factor of the two sets of diffuse matt ceramic grey scale standards, in the geometries 45:0 and 0:45 within the V(λ)-range (380 nm to 780 nm)

févr-14

On time, no technical issue.

The three grey-scale sets, 88% white, 40% grey, 5% deep grey, of Del. 1.1.1. containing a total number of nine samples were altogether calibrated according to the measurand spectral radiance factor in the diffuse reflection measurement geometries 45:0 and 0:45, within the wavelength range 380 nm to 780 nm, which is the so-called V(λ)-range of the human visual perception. This calibration was performed with the robot-based gonioreflectometer of PTB.

1.1.6 Calibrate of the spectral radiance factor of the colour standards in the standardised reflection geometries 45:0 and 0:45 within the V(λ)-range (380 nm to 780 nm)

févr-14

On time, no technical issue. The three coloured matt ceramic tile sets of red, green and deep blue of Del. 1.1.5. containing a total number of nine samples were altogether calibrated according to the measurand spectral radiance factor in the diffuse reflection measurement geometries 45:0 and 0:45, within the wavelength range 380 nm to 780 nm, which is the so-called V(λ)-range of the human visual perception. This calibration was performed with the robot-based gonioreflectometer of PTB



• 88 % white, 40 % grey and 5 % dark grey

• Red, green and dark blue

• Comparison of a set of 3 grey-scale standards and 3 colored standards




Status and activity

1.1.3 Measurement of the ceramic grey scale standards in the geometries 45:0 and/or 0:45 within the V(λ)-range (380 nm to 780 nm)

Mai 14, Févr 15

The measurements of the samples are ongoing and in time. The first measurements at MIKES and UA are finished. After reshipment of the samples they were remeasured with the robot-based gonioreflectometer at PTB in order to check for possible deviations of the reflections values. Currently the samples are for the 2nd measurement cycle at CSIC and SP.

1.1.7 Measurement of the ceramic colour standards in the geometries 45:0 and/or 0:45 within the V(λ)-range (380 nm to 780 nm)

Mai 14, Févr 15

The measurements of the samples are ongoing and in time. The first measurement at UA is finished. After reshipment of the samples they were remeasured with the robot-based gonioreflectometer at PTB in order to check for possible deviations of the reflections values. Currently the samples are for the 2nd measurement cycle at CSIC and SP.


● Photos of the different gonioreflektometers of the consortium: Comparison in 0:45 and/or 45:0 geometry




Star-type comparison:



Star-type comparison:

This month This month



Sample: xD-11

Sample: xD-14





• Evaluation of the internal “project key-comparison” • Determination of the KCRV and DOE • Publication of the data and the results • Possibly submission as “Key-Comparison” to the CCPR


WP1: Effect characterisation


Status and activity

1.1.9 Selection and preparation of a dedicated set of effect pigmented samples with high goniochromatic gamut

Août 14

On time, no technical issue. In cooperation with our collaborators Merck KGaA and Cramer Forschungsinstitut a collection of relevant effect pigmented samples was assorted. The compilation consists currently of 61 samples which are allocated and stored in a desiccator at PTB, Braunschweig.

See next slide


15 samples

46 samples



• 61 effect pigment samples: - different pigments - different concentrations - different gradations - different backgrounds (black/white)




Crystal Silver

same concentration as additionally carbon black

reduced concentration to same carbon black as


• Sample for the characterisation of Sparkle

Xirallic ® Crystal Silver

Aluminium pigments:

• Corn Flaks • Silver dollar

• METALURE®

different particle sizes

here ∅ ≈ 35 µm ⇒

Corn flakes Silver dollar



WP1: Effect characterisation, measurements


Status and activity

1.1.10 Calibration of the spectral radiance factor of the effect pigmented samples in the reflection geometries recommended in ASTM E2539-08

Nov 14

Christian


ASTM E2539-08: „Standard Practice for Multiangle Color Measurement of Interference Pigments“

8 in-plane geometries



DIN 6175-2 „Color tolerances in automobile lacquerings“

4 in-plane geometries



45°:-60° 45°:-30° 45°:-20° 45°:0° 45°:65° 45°:30°

15°:-30° 15°:0°

Appearance of a sample in ASTM geometries:

Appearance in an out-of-plane geometry:



456 Geometries

Measurements with the ARGon facility at PTB: ● 114 reflection angles θr = 0°- 70° , φr = 0° - 180° ● 4 incident angles θi = 0°, 22.5°, 45°, 67.5° ● includes the geometries of DIN and ASTM ● includes also the geometries of instrument manufacturers



For each geometry: ● Measure radiance of the sample: 2x (λ-intervals + dark signal) ● Measure radiance of the lamp 2x (λ-intervals + dark signal)

x 66 samples = 924 hours = 38,5 days

8 measurements x 456 geometries = 14 hours/sample



Colorstream Viola Fantasy



“Viola Fantasy”

white

black

θr [deg]

β(λ, θr)

θr [deg]

β(λ, θr)



“Lapis Sunlight”

white

black

θr [deg]

β(λ, θr)

θr [deg]

β(λ, θr)



Iriodin 9225

white black

θr [deg]

θr [deg]

β(λ, θr)

β(λ, θr)



446 geometries x 66 samples = 30096 files!

Next step: Data Analysis





Status and activity

1.2.1 Update of the robot-based gonioreflectometer with advanced light sources

Août 14

On time, no technical issue. For the robot-based gonioreflectometer of PTB two types of new relevant light sources were identified. For the extension of the wavelength scale into the deep UV, up to the so-called vacuum UV around 200 nm, a plasma light source with high UV output, realized with a laser-driven Xe-plasma. For the direct measurement of colour coordinates under D65 illumination with a luminance camera system a special lamp producing a D65-like illuminant, which was developed from commercial available components.

The deep-UV irradiation lamp consist of a laser driven light source which is converted in a directional light source for the gonioreflectometer application via an achromatic UV-lens and a special holographic UV-Diffuser.

The D65-lamp consists of a 12 V, 50 W tungsten halogen-lamp with a parabolic reflector attached to a special filter element producing a D65-like spectrum. The lamp-filter combination is mounted into a convection cooled lamp housing composed of cooling fins. Both developed lamp-systems can be mounted to the large rotation stage of the gonioreflectometer set-up where the lamps can be rotated by 360° to any desired angle relative to the sample under test.


PTB gonio update: D65-like light source Luminance camera


● Normalized spectrum of the D65-lamp (dashed line) in relation to the theoretical defined D65 illuminant (solid line).

PTB gonio update: D65-like light source


PTB gonio update: LDLS: Laser Driven Light Source

● Energetiq EQ-1500 with mounted lens-diffusor combination

UV protection helmet


Photo of direct output

Photo of filtered output (only UV)



1,0E-10

1,0E-09

1,0E-08

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1,0E-06

200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800

Phot

o cu

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Comparison of photo current (Sphere radiator <-> Laser Driven Light Source)

Photostrom-Kugelstrahler-WL1




Photostrom-LDLS-WL1

Photostrom-LDLS-WL2

Photostrom-LDLS-WL3

Photostrom-LDLS-WL4




Problems with high intensity output of “hard“ UV-radiation




Status and activity

1.2.2 Extension of the wavelength region for calibrations at the robot-based gonioreflectometer to the range 200 nm – 2500 nm

Août 15 In progress

1.2.3 Update of the CSIC gonioreflectometer in order to enlarge the spectral range of measurement to 380 nm – 1700 nm

Août 14

On time, no technical issue. The illumination system of the gonioreflectometer at CSIC has been modified to add an incandescent lamp as radiation source for the NIR. The so far used Xe-lamp will be further used in the VIS range. The NIR detection system has been designed with an InGaAs/InP detector 5 mm in diameter and an achromatic lens that images a circular 25 mm diameter surface of the sample to the detector. So the updated detection system is now formed by a single element detector from 780 nm to 1700 nm and by a spectroradiometer from 380 nm to 780 nm.



Photo of the GEFE (Gonio-Espectro Fotómetro Español) gonio-spectrophotometer at CSIC


xD-Reflect: WP1 Effect characterisation

Del. No. Deliverable description Delivery date Status and activity

1.3.1 Report describing the mode of selection of a representative set of effect pigmented colour samples for the current range of visible goniometric effects

Août 14

On time, no technical issue. From the 66 samples allocated in deliverable 1.1.9. a subset of 9 samples was selected. This are in detail, 2 achromatic aluminium flakes (corn flake and silver dollar) and an aluminium-like effect pigment sample. One sample with a high-chromatic gamut (Merck Colorstream Viola Fantasy) and 5 samples with a basic appearance of blue colour under diffuse irradiation made of different substrates. These samples were taken from the different product lines of effect pigments of company Merck. In detail this are the effect pigment lines named Colorstream, Iriodin, Xirallic, Miraval and Pyrisma. All of these product lines are different in their composition. Colorstream pigments are made of synthetic silicon dioxide coated with metal oxide layers. Iriodin pigments are made of thin plates of natural mica coated with metal oxide layers. Xirallic pigments are crystal effect pigments in the form of aluminia platelets covered with titanium oxide. Miraval pigments are based on synthetic produced calcium aluminium borosilicate, coated with metal oxides. Pyrisma pigments are based on specially developed titanium dioxide interference layers. The basic blue colour was chosen, because in the case of a goniochromatic colour shift the colour defining absorption minima can shift spectrally in both directions, which means to higher or lower wavelengths, resulting in the appearance of different colour impressions.


WP1: Effect characterisation Silverdollar 2154 Stapa Hydrolan

Cornflake 8154 Stapa Hydrolan

Iriodin 9119 Polar White

Xirallic T60-10 Crystal Silver

Colorstream T20-01 Viola Fantasy

Colorstream T20-04 Lapis Sunlight

Iriodin 9221 Rutile Fine Blue

Miraval 5424 Magic Blue

Xirallic T60-23 Galaxy Blue

Pyrisma T40-23 Color Space Blue


Goniochromatism, Sparkle, Graininess

Spatially resolved measurement (28 µm)

Luminance camera

Crystal Silver

Diffuse illumination

Directional illumination

BYK-mac


xD-Reflect: Effect samples So called “Flip-Flop Standards” of ( grey, blue, green)

Sean Hillman BUSINESS MANAGER T +44 (0)1782 764321 [email protected] Lucideon Ltd, Queens Road, Penkhull, Stoke-on-Trent, ST4 7 LQ, UK

10 cm


10 cm

Close-up view:

xD-Reflect: Effect samples


“Flip-Flop Standards” of (“golden” surface)

Sean Hillman BUSINESS MANAGER T +44 (0)1782 764321 [email protected] Lucideon Ltd, Queens Road, Penkhull, Stoke-on-Trent, ST4 7 LQ, UK

10 cm

xD-Reflect: Effect samples



Del. No. Deliverable description Delivery date Status and activity

1.4.1 Establishment of a data representation algorithm for multi-dimensional BRDF in order to create a standard format for data files

Août 14

On time, no technical issue. In accordance with CSIC and UA it was agreed to use a data format for representation of the measured BRDF data based on a 5D multiplicity. These are in detail four angular coordinates consisting of two angles in spherical polar coordinates defining the direction of the incident radiation and another two angles in spherical polar coordinates defining the direction of the reflected radiation. The fifth dimension is given by the wavelength of measurement. These data can be stored in a text-based CSV file which can be read from many evaluation programs. Using this operational frame, measurements are fitted to an analytical or phenomenological function. Afterwards, reflectance, transmittance and reflectance factors can be calculated for all illumination/observation geometries. Using this operational frame, measurements can be fitted to analytical or phenomenological functions. Afterwards, the BRDF or the radiance factor can be calculated for all irradiation/observation geometries.



BRDF data based on a 5D multiplicity

Physikalisch-Technische Bundesanstalt Braunschweig und Berlin Bundesallee 100 38116 Braunschweig Dr. Andreas Höpe Arbeitsgruppe 4.24 “Reflexion und Transmission“ Telefon: 0531 592-4240 E-Mail: [email protected] www.ptb.de Stand: 10/14

Thank you very much for your attention

Documents

WP1 – Goniochromatism - xD Reflect · Höpe/Strothkämper xD-Reflect, 4th Project Meeting, Alicante, Spain page 2 of 68 • Short information about PTB • Infrastructure of WG