k oododdak ak qak qq-lab process monitoring service-lab

KKKKKODODODODODAK QAK QAK QAK QAK Q-LAB Process Monitoring Service-LAB Process Monitoring Service-LAB Process Monitoring Service-LAB Process Monitoring Service-LAB Process Monitoring ServicePROCESPROCESPROCESPROCESPROCESS CONTROL HANDBS CONTROL HANDBS CONTROL HANDBS CONTROL HANDBS CONTROL HANDBOOK OOK OOK OOK OOK • Z Z Z Z Z-6-6-6-6-6

Process Monitoring:Sensitometric Parameters

In addition to monitoring the keychemical and mechanical processparameters and processing KODAKAudit Strips, Process E-6, you shouldcontinue to use control strips fordaily monitoring of sensitometricparameters.Note: Monitor your densitometer toensure that it is operating properly.Drifting and inaccurate readingsoccur most often in the higher densi-ties. Proper densitometer perfor-mance is especially importantfor accurate monitoring of your pro-cess with KODAK Control Strips,Process E-6. Keep a record of allmaintenance (e.g., filter changes)performed on your densitometer.

Calibrate your densitometer dailyby following the manufacturer�sinstructions. To check densitometerconsistency, read the KODAK Trans-mission Densitometer Check Plaque(CAT No. 170 1986) and plot thevalues on the KODAK Process RecordForm (KODAK Publication No. Y-55).(The Transmission DensitometerCheck Plaque consists of six highlystable glass-mounted color filters, aneutral patch, and a clear patch. It is areference standard for checking thered, green, and blue response andphotometric repeatability of elec-tronic densitometers. We recommendthat you use the check plaque to eval-uate densitometer performance.)

CONTROL STRIPSKodak supplies control strips formonitoring processing of all KODAKPROFESSIONAL EKTACHROME Filmsin KODAK Chemicals, Process E-6. KODAK Control Strips, Process E-6, are precisely exposed neutral-densityscales on KODAK PROFESSIONALEKTACHROME Film E100G.

We recommend that you process atleast 3 control strips per day or shift.Process a strip at the beginning of theshift (before you process customerfilm), another strip in the middle ofthe shift, and another strip at the endof the shift. We also recommend thatyou process a control strip withcustomer film at regular intervals.Handle and process control stripsaccording to the instructions pack-aged with them. Use only certifiedStatus A densitometry to read thecontrol-strip densities.

KODAK Control Strips,Process E-6(Cat No. 106 3239)

These 35 mm x 5¼-inch strips aresupplied in a box of five foil packagesthat contain 10 strips each. Each boxincludes a reference strip. The ends ofthe strips are perforated for use withstandard control-strip racks. Eachstrip has five neutral-density steps;a raised dimple is located on the

Revised 7/04

emulsion side at the low-density end.Read and plot the following steps tomonitor the sensitometric parametersof Process E-6:

Step 1 D-minStep 2 Toe density (TD)Step 3 Low density (LD)Step 4 High density (HD)Step 5 D-max

Raised dimple

Identificationcode

1 D-MIN

TD

LD

HD

D-MAX

2

3

4

5

DATE:

5¼-Inch Strip


PROCESS MONITORING: SENSITOMETRIC PARAMETERS • 7/045-2

KODAK Control Strips,Process E-6(Cat No. 173 3682)

These 35 mm control strips aresupplied in 100-foot rolls of approxi-mately 120 strips with cutoff notchesat 9½-inch (24.1 cm) intervals. Areference strip is included with eachroll. The roll is wound emulsion sidein, with the D-min ends of the stripstoward the outer end of the roll.

Each strip contains 11 equal-increment neutral-density steps and3 color patches. Steps 1, 3, 5, and7 are marked by a �U� in the step.Read and plot the following steps tomonitor the sensitometric parametersof Process E-6:

Step 1 D-minStep 3 Toe density (TD)Step 5 Low density (LD)Step 7 High density (HD)D-max area D-max

ESTABLISHINGCONTROL-STRIP AIMSYou can use either of two methods toestablish aims for a new batch ofcontrol strips.

The first method requires process-ing audit strips and control strips(from the new batch), using theKODAK Q-LAB Densitometer Corre-lation Strip to determine correlationfactors for your densitometer, andapplying the correlation factors to theaudit-strip aims supplied by Kodak.

This procedure, described on page 5-3,enables you to compare your processaims directly to the Process E-6 aims.Following this procedure will help toprevent your process from driftingfrom the Process E-6 aim as you usedifferent batches of control strips.

The second method of establishingaims�using the reference strip andcorrection factors�is the sameprocedure that you have routinelyused. This method will provide youwith aims that are similar to thosedetermined by using Method 1.Following this procedure will alsohelp to prevent your process fromdrifting from the Process E-6 aim asyou use different batches of controlstrips, but you will not be able tocompare your process aims directlyto the Process E-6 aims. To use thismethod, follow the procedure givenon page 5-6.

Important: There is one perfor-mance aim for Process E-6. Sensi-tometric aims for Process E-6 arereported in terms of audit-strip densi-ties. Method 1 uses your audit-stripaims to establish control-strip aimsdirectly. Method 2 uses the referencestrip to establish your control-stripaims indirectly.

Method 1 was specially developedfor Q-LAB Service. It is more accuratethan Method 2 because it uses addi-tional tools (densitometer correlationstrips, audit strips, etc) and data(audit-strip aims, etc). Method 2 is asimpler procedure, but because ituses an intermediate tool�the refer-ence strip�the calculated aims maybe less accurate than those deter-mined with Method 1. If you carefullycalculate aims by both methods tocompare them, and you determineslightly different aims, use the aimscalculated with Method 1.Note: When you change to a newbatch of control strips, aim shifts thatare within the following tolerancescan be attributed to small differencesbetween batches of control strips;shifts that exceed these tolerancesmay indicate an error in calculatingaims or a shift in your densitometeror process.

D-min ± 0.02TD ± 0.02LD ± 0.03HD ± 0.04D-max ± 0.06

9½-Inch Stripfrom 100-Foot Roll

Identification code(reversed w hen stripis em uls ion side up)

Circ le to aidin locatingD-m ax area

Cutoff notch

Yellow

Magenta

Cyan

D-m in

TD

LD

HD

D-m ax area

E-69111

7/04 • PROCESS MONITORING: SENSITOMETRIC PARAMETERS 5-3


Processing audit strips and deter-mining customized audit-strip aimseliminates the need to use the refer-ence strip and the correction factorssupplied with the control strips.Method 1 ties your aims directlyto the Process E-6 aims.

Method 1When you use Method 1, you cancompare your aims for each batchof control strips directly to theProcess E-6 aims by�

• processing audit strips and controlstrips from the new batch

• using the KODAK Q-LAB Densitom-eter Correlation Strip, Process E-6,to determine correlation factors foryour densitometer

• applying the correlation factors tothe audit-strip aims supplied by Kodak to determinecustomized audit-strip aims.

• comparing your audit-strip aimswith the average densities of yourprocessed audit strips to establishyour process level

• comparing the densities of yourprocessed audit strips with thedensities of your processed controlstrips to establish control-strip aims.

Follow these steps (or use Worksheet 3 in Section 17) to determine aim values for D-min, TD, LD, HD, andD-max:

Step Why?

1. In the same run, process 2 audit strips and 2 controlstrips from the new batch per day for 4 days. Processthe strips when your process is in good chemical,mechanical, and sensitometric control, and at a levelacceptable for processing customer film.

5. Ensures that there are no gross differences betweenyour densitometer and the densitometer used toestablish the Process E-6 aims.

4. Provides densitometer correlation factors; thesefactors provide a direct link to the Process E-6 aimsby telling you the difference between your densitometerand the densitometer used to establish the Process E-6aims.

3. Provides average density readings of the correlationstrip made with your densitometer.

2. Provides accurate and consistent readings; densi-tometry other than Status A may provide inaccuratereadings.

1. Needed to determine your process level andconsistency.

5. Compare your densitometer correlation factors (fromstep 4) with these tolerances.

D-min ± 0.02 HD ± 0.12TD ± 0.03 D-max ± 0.15LD ± 0.05

If your factors are within tolerances, your densi-tometer is operating properly.If your factors are not within these tolerances, check orservice your densitometer and repeat steps 3 and 4.

4. Subtract the Status A densities given in the instructionsfor your correlation strip from your average densities(from step 3).Example of determining densitometer correlationfactors:

3. Measure the red, green, and blue Status A densitiesof your Q-LAB Densitometer Correlation Strip in thecenter of the D-min, TD, LD, HD, and D-max stepstwice. Average the readings for each step.

2. Calibrate and zero your densitometer. Use only certifiedStatus A densitometry.

LD Step Red Green Blue

Your average densitiesfor the densitometercorrelation strip 1.02 1.03 1.04

Densities from theinstruction sheet – 1.03 – 1.03 –1.03

Densitometer correlationfactors – 0.01 0.00 + 0.01

KODAK Q-LAB Process Monitoring Service PROCESS CONTROL HANDBOOK • Z-6

PROCESS MONITORING: SENSITOMETRIC PARAMETERS ● 7/04 5-4

Step Why?

6. Add your densitometer correlation factors (from step 4) to the audit-strip aims supplied by Kodak.

Example of determining your audit-strip aims.


Densitometer correlation factors

Audit-strip aims from

-0.01

0.00

+0.01

Kodak +1.04 +1.04 +1.04

Your audit-strip aims

1.03

1.04

1.05

7. Measure the red, green, and blue Status A densities of

your 8 processed audit strips (from step 1) in the center of the D-min, TD, LD, HD, and D-max steps. Average the readings for each of the 5 steps.

Compare the densities of each audit strip with the average of your 8 strips. The densities of each strip should be within 10 percent of the average.

If the density (or densities) of any single audit strip differs from the average by 10 percent or more, disregard the densities for that strip, and recalculate your average.

OR

If the density (or densities) of any pair of audit strips from the same process run differs from the average by 10 percent or more, discard the audit strips and the control strips from the same run. Process an additional pair of audit strips and control strips. Then use the readings from the new strips to recalculate your average.

6. Customizes the audit-strip aims for your densitometer.

7. Provides average density readings of your processed audit strips.

Provides a tolerance for your processed audit strips. Ensures that data used to calculate aims are based on

a stable process level.



Step Why?

8. Measure the red, green, and blue Status A densitiesof your 8 processed control strips (from step I) in thecenter of the D-min, TD, LD, HD, and D-max steps.Average the readings for each of the 5 steps.

Compare the densities of each control strip with theaverage of your 8 strips. The densities of each stripshould be within 10 percent of the average.

If the density (or densities) of any single control stripdiffers from the average by 10 percent or more,disregard the densities for that strip, and recalculateyour average.

OR

If the density (or densities) of any pair of control stripsfrom the same process run differs from the average by10 percent or more, discard the control strips and theaudit strips from the same run. Process an additionalpair of control strips and audit strips. Then use thereadings from the new strips to recalculate youraverage.

8. Provides average density readings of your processedcontrol strips.

10.Add your process correction factors (from step 9)to your average control-strip densities (from step 8).Record these aims on Form Y-33. The aim for LDspread is always zero (0). For information on usingForm Y-33, see page 5-7.

Example of determining control-strip aims:

9. Subtract your average audit-strip densities (from step 7)from your audit-strip aims (from step 6).

Example of determining your process correctionfactors:


Your audit-strip aims 1.03 1.04 1.05Average audit-strip

densities – 1.03 – 1.05 –1.04

Process correctionfactors 0.00 – 0.01 + 0.01


Process correctionfactors 0.00 0.0– 0.01 + 0.01

Average control-strip densities + 1.02 + 1.02 + 1.02

Control-strip aims 1.02 1.01 1.03

Provides a tolerance for your processed control strips.

Ensures that data used to calculate aims are based ona stable process level.

9. Provides process correction factors; these factorstell you the difference between your process level andthe Process E-6 aim level.

10.Provides customized control-strip aims for the newbatch of control strips. Use these aims until youchange to another batch of control strips.



Step Why?

Method 2Method 2 lets you easily determinecontrol-strip aims by using the refer-ence strip and the correction factorssupplied with the control strips toadjust your aims to the Process E-6aims. It does not, however, providea thorough understanding of yourprocess level because it uses an inter-mediate tool (the reference strip) toestablish aims.

Follow these steps to determine aim values for D-min, TD, LD, HD, and D-max:

1. Provides accurate and consistent readings; densi-tometry other than Status A may provide inaccuratereadings.

1. Calibrate and zero your densitometer. Use only certifiedStatus A densitometry.

3. Apply the correction factors supplied with the controlstrips to the density readings from step 2. Theseadjusted density values are the aim values for thisbatch of control strips. Record these aims onForm Y-33. The aim for LD spread is always zero (0).For information on using Form Y-33, see page 5-7.

2. Measure the red, green, and blue Status A densities ofthe reference strip supplied with the control strips inthe center of the D-min, TD, LD, HD, and D-max steps.If you have more than one box of control strips of thesame code number, read the reference strips from allavailable boxes and average the density readings.

3. Adjusts for the difference between the process used forthe reference strips and the Process E-6 aim. Providesadjusted control-strip aims for the new batch of controlstrips.

2. Provides density readings of the reference strip(s)measured with your densitometer. The reference stripswere processed in an in-control process.



KODAK PLOTTINGFORM FORPROCESS E-6(KODAK Publication No. Y-33)

This form is similar to KODAKPublication No. Y-55, KODAK ProcessRecord Form, but it includes areas forplotting two additional parameters:LD (low density) spread and TD (toedensity).

LD Spread: Color balance is a criticalpart of image quality. LD spreadprovides a convenient means ofmonitoring color balance. Thismeasurement is made from the LDstep of the control strip becausecolor-balance changes affect imagequality most at that density level. Thechart for plotting LD spread includesno space for recording aims or limitsbecause you use it to monitorchanges in the plots derived from thered, green, and blue densities of theLD step in relation to each other andto the aim line. Ideally, the R � G LDspread and the B � G LD spread willequal zero.

Toe Density: Because professionalphotographers are very sensitive tocolor shifts in the toe densities (TD) oftheir transparencies, it is important tomaintain the control and consistencyof this parameter (see page 5-10).

Use Form Y-33 to record the differ-ences from aim of the D-min, TD, LD,HD, and D-max steps, as well as LDspread, of your control strips. Yourdata plots on Form Y-33 become arunning record of your process.

Using Form Y-33Use a separate form for each pro-cessor. Record the name (or identitycode) of the processor in the blanklabeled �Machine.� Record the control-strip code number in the blank at thetop of the form.

To calculate and plot yourdifferences from aim, follow thesesteps:1. Process a control strip and

measure the red, green, and bluedensities of D-min, TD, LD, HD,and D-max. Record the date andtime on the form.

2. Subtract your control-strip aimsfrom the control-strip readings tocalculate the differences.Example of determining the differ-ences between your control-stripreadings and aims:

3. Plot the differences on Form Y-33.Plot differences that are largerthan the corresponding aim values(+ values) above the aim line, andthose that are smaller than theaim values (– values) below theline. Use red, green, and bluepencils to plot the values for thecorresponding density readings.


Control-strip readings 1.07 1.03 1.04Control-strip aims – 1.05 – 1.06 –1.04

Differences + 0.02 – 0.03 0.00



2. To use the graphic method to deter-mine the B � G LD spread, countthe number of blocks between theLD blue plot and the LD green plot.If the LD blue plot is above the LDgreen plot, plot the B � G LD spreadabove the aim line. If the LD blueplot is below the LD green plot,plot the B � G LD spread below theaim line.

For strip No. 1 in the illustrationabove, the LD blue plot is 2 blocksbelow the LD green plot. Therefore,the B � G plot is 2 blocks below theaim line. For strip No. 2, the LD blueplot is 2 blocks above the LD greenplot, so the B � G plot is 2 blocksabove the aim line, etc.

OR

To calculate the B � G LD spread,subtract the green difference fromaim from the blue difference fromaim.

For LD Spread, plot the differ-ence between the LD variationsfrom aim by following these steps:1. To determine the R � G LD spread

by using a simple graphic method,just count the number of blocksbetween the LD red plot and the LDgreen plot on Form Y-33. If the LDred plot is above the LD green plot,plot the R � G LD spread above theaim line. If the LD red plot is belowthe LD green plot, plot the R � GLD spread below the aim line.

For strip No. 1 in the illustration,the LD red plot is 2 blocks abovethe LD green plot. Therefore, theR � G plot is 2 blocks above the aimline. For strip No. 2, the LD red plotis 2 blocks below the LD green plot,so the R � G plot is 2 blocks belowthe aim line, etc.

OR

To calculate the R � G LD spread,subtract the green difference fromaim from the red difference fromaim.

Example (see strip No. 1 in the illus-tration above):

Example (see strip No. 1 in the illus-tration above):

If the B � G LD spread is positive,plot the point above the aim (0)line; if the B � G LD spread is nega-tive, plot the point below the line.

If the R � G LD spread is positive,plot the point above the aim (0)line; if the R � G LD spread is nega-tive, plot the point below the line.

LD red differencefrom aim 0.03)

LD green differencefrom aim – (+ 0.01)

R – G LD spread + 0.02)

LD blue differencefrom aim – 0.01)

LD green differencefrom aim – (+ 0.01)

B – G LD spread – 0.02)

LD SPREADR – GB – G

LDRED__________GREEN________BLUE_________

-+

0.10

1 2 3

0.10

0.05

0.05

0

-+

0.10

1 2 3

0.10

0.05

0.05

0



The table below lists the variations from aim indicated by each of the colorzones on Form Y-33.

Using the Color ZonesForm Y-33 includes color zonessimilar to those on Forms Y-34,Y-35, and Y-36.

• White Zone�When all the chem-ical and mechanical parameters arein good control, control-strip plotsthat are consistently in the whitezone confirm that your process is ingood control. Continue to monitorand plot the chemical, mechanical,and sensitometric parameters.

• Yellow Zone�Plots in the yellowzone indicate a marginal controlcondition.

A control strip can plot in theyellow zone even if your process isin good control. Carefully examinethe plots of the chemical andmechanical parameters on FormsY-34, Y-35, and Y-36 for any changes.Also examine your densitometer,the processor, and the control strip.

• Orange Zone�Plots in the orangezone indicate an out-of-controlcondition. It is possible (althoughvery unlikely) that a control stripcan plot in the orange zone even ifyour process is in good control.Carefully examine the plots of thechemical and mechanical parame-ters, the densitometer, the pro-cessor, and the control strip todetermine the cause of the change.You must locate the cause and takethe appropriate corrective action.Then verify that the process hasreturned to a good state of controlbefore processing customer film.Note: The cyan zone for LD spreaddoes not indicate the control ofyour process. Examine the plot todetermine the long-term color-balance consistency of your process.

Evaluating Data Plots onForm Y-33Your control-strip plots on Form Y-33will confirm the control of yourprocess, or provide a clear record ofvariations in the performance of yourprocess. Non-random variationsoccur for two reasons:1. Physical damage or improper

handling of the control strips(e.g., handling that causes fogging)or variations in your densitometer(e.g., improper calibrations) cancause changes in the density read-ings of your control strips. Investi-gate and correct the cause(s) ofthese changes.

2. Changes in the chemical and/ormechanical parameters of theprocess can cause changes in thedensity readings of your controlstrips. Your plots on Forms Y-34,Y-35, and Y-36 will indicate thesechanges. Base your process-controldecisions on the control plots forthe chemical and mechanicalparameters of your first developer,reversal bath, and color developer.

* If you routinely monitor and control allother chemical and mechanical parame-ters, the effects of changes in agitation orpH are more reliably detected by measur-ing control strip densities.

It is not always possible to measureall chemical and mechanical parame-ters that can affect image quality.(Agitation and color-developer pHare two parameters that cannot bemonitored conveniently.*) Therefore,control strips are an important partof process control.

* Form Y-33 does not show the whole orange zone for this step.

retemaraPenoZroloC

etihW wolleY egnarO

nim-D 20.0+ot0timilrewoloN

30.0+ot20.0+ 50.0+ot30.0+

DT)ytisneDeoT(

30.0+ot30.0– 40.0–ot30.0–40.0+ot30.0+

01.0–ot40.0–01.0+ot40.0+

DL)ytisneDwoL(

40.0+ot40.0– 50.0–ot40.0–50.0+ot40.0+

*51.0–ot50.0–*51.0+ot50.0+

DH)ytisneDhgiH(

60.0+ot60.0– 80.0–ot60.0–80.0+ot60.0+

*02.0–ot80.0–*02.0+ot80.0+

xam-D 01.0–ot0timilreppuoN

31.0–ot01.0– 02.0–ot31.0–



2. Monitoring TD lets you detect some process problems earlier than you could if you monitored only the D-min and LD steps.

3. Monitoring TD also enables you to detect multiple process problems� i.e., when two or more parameters are out of control at the same time.

Important: Before you monitor the TD step, make sure that your control- strip aims are correct. (If you have not established control-strip aims, follow the procedure for Method 1 on page 5-3. The procedure enables you to compare your process aims directly to the Process E-6 aims.)

Monitoring Toe DensityThe TD (toe density) step, at a densityof approximately 0.35, is unique tothe KODAK Q-LAB Process Monitoring. Service. We recommend that you carefullymonitor this step for the following reasons:1. The toe density corresponds to the

highlights of many photographicimages. If your process does notmaintain neutral toe densities, thehighlights of customer images willshow an objectionable colorbalance.



These examples show the effects ofpoor first-developer agitation on theLD and TD steps. This conditioncauses lower densities to increase (inthe TD and D-min regions).

Therefore, you will usually detect thisproblem sooner at TD than at LD.

The response of the TD step toprocess changes is generally thesame as the response of the LD step.You will detect some process prob-lems first by monitoring the LD step

(problems that have a greater effecton upper-scale densities) and othersby monitoring the TD step (problemsthat have a greater effect on lower-scale densities).

-+

0 .1 0

0 .1 0

0 .0 5

0 .0 5

0

LD

TD

-+

0 .1 0

0 .1 0

0 .0 5

0 .0 5

0



In this example, LD is above aimand TD is below aim. This indicatesthat more than one chemical ormechanical parameter is out ofcontrol. In this case, the first devel-oper was overconcentrated andunderreplenished. If the lab was toadjust the first-developer time ortemperature to control LD, TD wouldgo even lower, and then three param-eters would be out of control.

The TD and LD steps respond simi-larly to many process problems, soyou can use the same diagnostics forTD that you use for LD. See thecontrol-chart examples in KODAKPublication No. Z-119, or make adjustments based on yourexperience in monitoring the LD step.

(The LD step is called the �Speed�step in the examples in PublicationNo. Z-119.)

If you detect a change at the TDstep without a change at the LD step,follow the diagnostics for the processproblem(s) that causes the sameeffect at LD. If the LD and TD steps

change in different directions(e.g., LD goes yellow and TD goesblue), this usually indicates that morethan one chemical or mechanicalparameter is out of control. In thiscase, measure all chemical andmechanical parameters to determinewhich parameters are out of control.

LD

TD

-+

0 .1 0

0 .1 0

0 .0 5

0 .0 5

0

-+

0 .1 0

0 .1 0

0 .0 5

0 .0 5

0

PROCESS MONITORING: SENSITOMETRIC PARAMETERS • 7/04 5-13


monitor your sensitometric parame-ters and confirm your chemical andmechanical measurements. The chartbelow summarizes the steps of usingchemical, mechanical, and sensi-tometric data to monitor and controlyour process.

SUMMARYRemember that to achieve processcontrol, you must monitor andcontrol all chemical and mechanicalparameters. Base most of yourprocess-control decisions on thechemical and mechanical parameters,and process control strips daily to

M easure all keychem ical and m echanica l

param eters, and p lo tvaria tions from a im .

Are a llparam etersin contro l?

Are a lldensities

in contro l?

Yes, buttrend is

detected

No

No

Yes

Yes

Continue orresum e processing

custom er film .

·

·

Process contro l s trip .

M easure densities and p lo t d ifferences from a im .

·

·

Recheck m easurem ent(s).

F ind cause(s) and take corrective action (see d iagnostic charts).

·

·

·

·

Stop processing custom er film .

Recheck m easurem ents.

F ind and elim inate cause(s).

Recheck chem ical and m echanical param eters.

·

·

·

·

Recheck all key chem ical and m echanical param eters.

Check other possib le causes.M onitor process c lose ly.

Process contro l s trips frequently to m onitor trend.

k oododdak ak qak qq-lab process monitoring service-lab

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