David Hunter Cell Color Measurement on Budget. Audience

Transcription

1 Audience Creative/ Brand Owner! You own - your suppliers, producers own instrument! How well do they match! Use one Instrument for Spot, and different one for Process? Production/ Press Press! Proofer uses on Instrument, Press uses a different one! Compare Proof to Press- How instrument affects results?! A LOT... 1

2 What You Will Learn: Measuring Color is Complex! If Instrument is wrong, measure color doesn t matter! What causes an instrument to be wrong! How to assess instruments! Against itself, and other instruments, on different substrates! Introduce Instrument Gauge Factor! Number that determines your forgiveness for instrument variation! Introduce E-Factor/delta E Stack! Understand how instrument precision affects your workflow Terms and Definitions! E- Everything in this presentation based on delta E 2000! Average, Standard Deviation, CRF 95 th Percentile. Peak,! E-Factor- Term to represent CRF 95 th percentile! Cumulative Relative Frequency at 95 th percentile E! Precision! Consistency, Repeatability, Reproducibility! Accuracy! How close to Reference Device! Instrument Gauge Factor (IGF)! Variation allowed for Instrument differences 2

3 Agenda Comparison of Measurement Devices! Four Different Assessments! Desire to have more instruments in supply chain... lower cost Precision vs Accuracy! What is the difference! How to Judge Accuracy Practical Ways to understand and use the Results! Turn the numbers into meaningful actions Instrument Deviation- All Different... Which one is Right?! Before Christmas or After? 3

4 Color Measurement on Budget Instrument Deviation- All Different... Instrument Deviation- All Different... Which one is Right?! 3 Data Loggers! Temperature: Which one is Right?! Measurement Devices! Within Instrument! Between Instrument! 65.6, 65.7, 64.2! Between Surfaces! Humidity! Compare to Reference! 18.9, 17.9,

5 Vendors Invited to Participate in Study Instrument Requirements- Less than $1,000! Color Sentinel! Colorix Nano! Datacolor ColorReader Pro, Spyder! Nix Pro Color Sensor! Variable ColorMuse! X-Rite Color Capsure, Color Munki Vendors Invited to Participate in study Instrument Requirements- Less than $1,000! Color Sentinel- Agreed! Colorix Nano- Agreed! Datacolor ColorReader Pro, Spyder - Declined! Nix Pro Color Sensor- Agreed! Variable ColorMuse- Agreed! X-Rite Color Capsure, Color Munki- Agreed 5

6 Vendors Invited to Participate in Study Instrument Software- Measure custom target- export data! Color Sentinel! Colorix Nano! Datacolor ColorReader Pro, Spyder - Declined! Nix Pro Color Sensor! Variable ColorMuse! X-Rite Color Capsure, Color Munki- Proprietary- not possible Vendors Product Capability Classification! Color Sentinel- Spectrophotometer! Colorix Nano- Colorimeter! Nix Pro Color Sensor- Colorimeter! Variable ColorMuse- Colorimeter Comparison Instrument for reference- #1 sold instrument! X-Rite i1pro - Spectrophotometer 6

7 Difference between Spectral and Colorimetric? Colorimetric! Tristimulus data (CIE-Lab, XYZ, etc)! 3 numbers define the color! Illuminant Dependent- Number only good for one light source Spectral! Spectral reflectance of visual spectrum ( nm)! 34 numbers define the color (10nm Increments)! Illuminant Independent- Number good for any light source Vendors Product Capability + Pricing Classification! Color Sentinel- Spectrophotometer $999! Colorix Nano- Colorimeter $495! Nix Pro Color Sensor- Colorimeter $349! Variable ColorMuse- Colorimeter $ 59 Comparison Instrument for reference- #1 sold instrument! X-Rite i1pro Spectrophotometer $1,395 7

8 Vendors Product Capability+ Pricing+ Interface Classification! Color Sentinel- Spectrophotometer $999 Windows! Colorix Nano- Colorimeter $495 Windows, IOS! Nix Pro Color Sensor- Colorimeter $349 IOS! Variable ColorMuse- Colorimeter $ 59 IOS Comparison Instrument for reference- #1 sold instrument! X-Rite i1pro Spectrophotometer $1,395 Windows, Mac Testing Procedures- Four Key tests Qualifying How Instruments Measure Color 1 Within Instrument Precision! One Instrument Compared to itself 2 Between Like-Instrument Precision! Different Instruments, same manufacture compared 3 Same device, same color- between Textures measurement! RAL- sample- same color- four different textures 4 Accuracy- Print Industry Application! How similar to i1pro 8

9 Testing Procedures- Metrics Defining Color Differences! Calculate E: Average, Standard Deviation, CRF 95 th, Peak! Between all measurements! Measure common target multiple times for each test! Don t rely on one measurement of one target! Too many variables Testing Procedures- What Colors? Defining Color Target! Want target to be relative to print product! BCRA tiles are not relevant for most print applications! Desire a thorough color evaluation! Cover multiple points throughout visible spectrum! Calculate difference between multiple devices! Two Colors is not a good comparison! Debate with a vendor- they evaluated 12 colors, that they picked, 9

10 Color Measurement on Budget Profiling a Measurement Device Defining Precision: Test #1: Intra-Instrument! Use Same Target for All Devices Precision- Device Consistency to itself! If a device is not consistent, within your Expectations...! Measuring colors, multiple times consecutively and over time! Short and long term repeatability! 42 Patches- diverse sampling! 93% sampling of Visible Spectrum One InstrumentMultiple measurements of same color 10

11 Defining Precision: Test #2: Inter-Instrument Defining Precision on Textures: Test #3 Precision- Multiple Devices Consistency to each other! How similar do like instruments measure to one another? Precision- Same Devices Consistency different Texture! Same Instrument- Same Color- Different Texture Instrument 1 Patch 1 vs. Patch 3 Instrument 4 P2 vs. P3 P1-P2 Instrument 2 Instrument 3 P3 vs. P4 P2 vs. P4 Patch 1 vs. Patch 4 11

12 Accuracy- How close to Reference: Test #4 4. Accuracy- Match to Reference Instrument Bulls Eye represents Master Instrument, No Industry Master... X-Rite and Techkon are based on different references Instrument 1 Measure similarly to i1 Pro Instrument! Print Industries most popular instrument! May not be relevant to your application- but concept useful Master Instrument Instrument 2 Instrument 3 Instrument 4 12

13 But- How Close Is Close Enough????? Test #1 Within Instrument Precision What level of Precision relates to Workflow Tolerance! It Depends who s asking...! Manufacturing Definition- Take raw materials, create product, that meets customer expectations! Ways to qualify how close is close enough : we cover later! Everyone s has different Expectations, Requirements All Vendors provided 3 Instruments! Same Manufacturing Batch! We measured same target 3-5 times by each device! Calculated delta E (00) for Average, Standard Deviation, CRF 95 Percentile, and Peak for each measurement! Then averaged each value between the three instruments 13

14 Color Measurement on Budget Test #1 Within Instrument Precision (Intra) Test #1 Within Instrument Precision Color Muse- One Instrument to itself! Measured same target 5 times by same device Nix Senor- One Instrument to itself! Measured same target 3 times E E 14

15 Test #1 Within Instrument Precision Test #1 Within Instrument Precision Colorix Nano- One Instrument to itself! Measured same target 3 times Color Sentinel- One to itself! Measured same target 5 times E E 15

16 Test #1 Within Instrument Precision i1 Pro 2 One instrument to itself! Measured same target 5 times Comparison: Instrument Precision exact Instrument: Multiple Measurements by one exact $6000 E 16

17 Test #1 Summary: Within Instrument (Intra) Test #2 Between Instrument Precision (Inter) Multiple measurements from each Instrument CRF Ave SD Peak 1 i1 Pro CSS Nano Nix ColorMuse ! exact Scan E Color Muse- All three instruments compared! Measured same target 3 times by each device 17

18 Test #2 Between Instrument Precision Test #2 Between Instrument Precision Nix Senor- All three instruments compared! Measured same target 3 times by each device Colorix Nano- All three compared! Measured same target 3 times by each device E E 18

19 Test #2 Between Instrument Precision Test #2 Between Instrument Precision Color Sentinel- All three compared! Measured same target 3 times by each device i1 Pro 2 - All three instruments compared! Measured same target 3 times by each device E E 19

20 Test #2 Between Instrument Precision Colorix Nano Instrument! We measured the same target 5 times in a row by each device Test #2 Between Instrument Precision Colorix Nano Instrument! We measured the same target 3 times in a row by each device! Average, Stand Dev, CRF 95 th, Peak! Workflow E-Factor! 4 Colors, biggest delta 20

21 Test #2 Summary: Between Instrument (Inter) Multiple Instruments, comparing each other! Instrument CRF Ave SD Peak 1 i1 Pro CSS Nano ColorMuse Nix Test #2a Between Instruments: Actual i1pro2 s Different i1pro2 s Compared! Instrument CRF Ave SD Peak 1. i1pro2 Ham i1pro2 PU i1pro2 Beth i1pro2 TC ! i1 Pro2 Test ! CSS

22 Test #3 Between Surface Characteristics Test #3 RAL Target- 4 Textures RAL Target with 4 Different Textures Color Muse! 4mm Aperture ! Measure 4 textures, Compare between the 4 textures! Measured each patch 5 times, averaged values, then compare! Benefit Large Aperture devices! Score= ! Score is sum of all E/6: Average E difference

23 Test #3 RAL Target- 4 Textures Test #3 RAL Target- 4 Textures Nix Sensor Colorix Nano! 14mm Aperture ! 8mm Aperture, adjustable < ! Score= ! Score=

24 Test #3 RAL Target- 4 Textures Test #3 RAL Target- 4 Textures X-Rite i1 Pro 2 Color Sentinel! 2.5mm Aperture 3.5! 2.5mm Aperture ! Score= ! Score=

25 Test #3 RAL Target- 4 Textures Test #3 RAL Target- 4 Textures Barbieri LFP X-Rite exact! 8mm Aperture 3.6! 2mm Aperture ! Score=2.6! 1&2: L*=77 3&4: L*= ! Score= 9.76! Average E differences

26 Color Measurement on Budget Test #3 Surface Characteristics: Summary RAL Target with 4 Different Textures, Lowest E Average! Nano 1.07! ColorMuse 2.17! Barbieri LFP 2.57! CSS 4.46! i1 Pro ! Nix 5.45! exact 9.76 Test #4 Compare Instrument to i1 Pro 2 Using X42 Patch Target- Use all Measurements- Compare 26

27 Test #4 Compare Instrument to i1 Pro 2 Using X42 Patch Target- Use all Measurements- Compare Test #4 Compare Instrument to i1 Pro 2 Using X42 Patch Target- Taking average of all devices Comparison 27

28 Understand, Two Precise Instruments May Not Match One Another Device Variation Over Time Color Muse- 1 Year within Instrument Variation (2 Different) Beware of how different instruments can be... Ink, Screening, Substrate, Finishing all affect results Yes, we did change the way the LAB colors are measured- slight change expected Confirmed July 17 change- 3-4 E. 28

29 Device Variation Over Time Actual i1 Pro2- Over 18 months You will not see this difference with your eye Test #4 Compare to i1pro2, CRF 95 th E M0 X42 Target Measured Multiple times, three instruments Ave: Instrument CRF Ave SD Peak! exact ! CSS ! Nix ! Nano ! ColorMuse (<7/17) ! ColorMuse (>8/17)

30 Color Measurement on Budget Making Sense of Results: When Measuring Color- How Close is enough? Apply Numbers to your Expectation Requirements! When measuring length: What level Precision? Depends on you Expectation Requirements! Obvious differences in instrument precision and accuracy! And mixing instruments compounds the variation! Application Defines it...! Application Defines it... 30

31 Color Measurement on Budget Defining Your Expectations: E-Factor Defining Your Expectations: E-Factor On-Line Exercise or Hard Copy with iphone App! Qualifies your expectations, individual or group Once You Define Expectation (E-Factor) Sell-ability! Can apply to output device capabilities, and instrumentation! If Output device E-Factor <= Your E-Factor= Expectations Met 31

32 Defining Your Expectations: E-Factor Once You Define Expectation (E-Factor) Sell-ability! Can apply to output device capabilities, and instrumentation! If Output device E-Factor <= Your E-Factor= Expectations Met Defining Your Expectations: E-Factor Once You Define Expectation (E-Factor) Sell-ability! Can apply to output device capabilities, and instrumentation! If Output device E-Factor <= Your E-Factor= Expectations Met 5 6!*%&! 5 4 $$$ 32

33 How Precise is Precise Enough Instrument Gauge Factor- % Tolerance Instrument Variation! What Percent of Tolerance to give up to Instrument! 20%, 25%, 33% choices- higher number- less room for manufacturing! Example 1: 20% of Tolerance= 1/5 of 100%! Tolerance is 2 E- Instrument should be less than.4 (20%)! Within Instrument variation <.4! Provides for 2-.4= 1.6 E during manufacturing Test #1 Within Instrument- Your E-Factor + IGF What E-Factor each Instrument is capable for IGF= 20% Instrument CRF Workflow E-Factor 1 i1 Pro 2.12 < CSS.19 < Nano.22 < Nix.90 < ColorMuse.99 < 5.0! exact Scan.05 <

34 Test #1 Within Instrument Precision Concept of E Stack (E-Factor Stack) All Vendors provided 3 Instruments (Same Manuf. Batch)! Calculate CRF E 95 th Percentile for each Instrument Variation metrics add up or Stack on top of one another! Single Instrument Variation! Based on Instrument Gauge Factor and actual Instrument Variation! Compare Two Instruments- Variation Doubles! Add the variation on top of each other, apply IGF! Use ISIS to build profile, and i1 Assess Proof, Intelltrax measure Press, Exact for Spot!!!!! Four Instruments- Variation on top of Variation! Between 3 Instrument Variation Between 2 Instrument Variation Within Instrument Variation 34

35 Test #2 Between Instrument: E-Factor + IGF Test #2 Between Instrument: E-Factor + IGF What E-Factor each combo instruments for IGF= 20%, 33% Instrument CRF WF 20% WF EF 33% 1 i1 Pro 2.21 <1.1 <0.6 2 CSS.51 <2.6 <1.5 3 Nano.74 <3.7 <2.2 4 ColorMuse 1.1 <5.5 <3.3 5 Nix 1.8 <9.0 <5.5! Remember: Same Manufacturing Batch Review Screen Shot of Instrument Comparison! Instrument CRF E-Factor 1 Nano Between 3 Instrument Variation Between 2 Instrument Variation Within Instrument Variation 35

36 Test #2a Between Instruments: E-Factor + IGF Different i1pro2 s Compared Instrument CRF WF 20% WF 33% 1. i1pro2 Ham.36 <1.8 < i1pro2 PU.43 <2.2 < i1pro2 Beth.56 <2.8 < i1pro2 TC.81 <4.1 <2.5! i1 Pro2 Test.21 <1.1 <0.6! CSS Test.51 <2.6 <1.5 Test #2a Between Instruments: E-Factor + IGF Different i1pro2 s Compared 36

37 Test #4 Between Non-Like Instruments Cross Referencing Different Instruments with i1 Pro2 Instrument CRF WF 20% WF 33%! exact ! CSS ! Nix ! Nano ! ColorMuse (<7/17) ! ColorMuse (>8/17) Between 3 Instrument Variation Between 2 Instrument Variation Within Instrument Variation Test #4 Compare Instrument to i1 Pro 2 Using X42 Patch Target- Taking average of all devices Comparison 37

38 Very Critical to Understand this Variable Implementing Color Control Requires Multiple Devices! Build Profile with isis or Barbieri LFP! Assess Conformance with i1pro or some other device! Understand- Introduces delta E Stack impact on Conformance Very Critical to Understand this Variable Implementing Color Control Requires Multiple Devices! Capture Color Palette with i1, Render through profile ISIS! Assess on press with Intellitrax and Exact or SpectroDens! Inline Measurement HP Indigo or Epson co-relate with ISIS! Understand- Introduces delta E Stack impact on Conformance Durst Rho over 1yr E to ICC 38

39 Precision related to Instrument Price Repeatability of device! Obviously, you often get what you paid for...! Purchase Quality product- cry only once (when you buy it)! Always exceptions! Substrate characteristics make a huge difference! Manufacturing Batches! My experience- devices manufactured at same time are more alike! Purchase multiple at same time if used for shared purposes Results- Instrument Measure Differently! Need to calibrate, and routinely monitor all devices! Measurement devices change: Temp, bulb aging, dust, dropped 39

40 Results- Instrument Measure Differently! Need to calibrate, and routinely monitor all devices! Measurement devices change: Temp, bulb aging, dust, dropped! Substrate, Screening, Inks, all influence Measurements! No two Instruments measure the same, some more than others Results- Instrument Measure Differently! Need to calibrate, and routinely monitor all devices! Measurement devices change: Temp, bulb aging, dust, dropped! Substrate, Screening, Inks, all influence Measurements! No two Instruments measure the same, some more than others! Understand the Inherent Differences between devices! Appropriate for your workflow! Accommodate Tolerances or Instruments accordingly 40

41 Results- Instrument Measure Differently! Need to calibrate, and routinely monitor all devices! Measurement devices change: Temp, bulb aging, dust, dropped! Substrate, Screening, Inks, all influence Measurements! No two Instruments measure the same, some more than others! Understand the Inherent Differences between devices! Appropriate for your workflow! Accommodate Tolerances or Instruments accordingly! Instruments can be Harmonized to minimize this difference! Harmonization captures substrate, ink, screening variables! Great Minimizes Mixing and Matching Color Problems 41