A Quick Reference Guide to Some Processing Problems and s: Color Negative Film Process - C41, C41B, C41RA Color Print Paper Process - EP2, RA4 Several variables in processing can affect the final quality of the finished product adversely. By regularly processing control strips and plotting the results it is possible to identify by trends small deviations to the process and therefore correct any underlying problems before they become serious. Any sudden deviation from the normal is also identified sooner and steps can be taken to correct the process quickly. In general a steady decrease or increase in activity is probably to do with replenishment rates. If a sudden change in activity occurs, the first checks to be made should be: 1) Densitometer (check calibration, check control strip batch) 2) Temperature (use a reliable thermometer) 3) Development time (if the machine has a variable speed control) 4) Agitation (check recirculation pump; check nitrogen burst; check filter blockage) 5) Levels - (check solutions levels) The following charts will help you identify some of the most common causes of out of control plots, when using Profile control strips but they are by no means exhaustive and it is not uncommon for two or more causes to be a problem at the same time. Out of date and badly stored control strips will give adverse results. - 1 -
C41 FILM Systems High Speed Values 1) Excessive developer temperature 2) Over-replenishment of developer 3) Too long a development time 4) Incorrect preparation of developer replenisher 5) Incorrect preparation of developer tank solution 1) Reduce developer temperature 2) Reduce replenishment rate 3) Decrease development time 4) Discard remaining replenisher and prepare fresh in accordance with instructions 5) Check preparation of solution/add water and starter Low Speed Values 1) Low developer temperature 2) Inadequate developer replenishment 3) Too short a development time 4) Incorrect preparation of developer replenisher 1) Increase developer temperature 2) Increase replenishment rate 3) Increase development time 4) Discard remaining replenisher and prepare fresh in accordance with instructions High Retained Silver (YP) Values Sudden Increase in Mask and Speed Values 1) Inadequate bleaching time. 2) Under-replenishment of bleach. 3) Incorrect preparation of bleach or faulty replenishment. 4) Insufficient aeration. 5) Low Temperature. Contamination of developer tank solution 1) Increase bleaching time. 2) Increase bleach replenishment rate. 3) Discard replenisher solution and prepare fresh. 4) Increase aeration. 5) Increase temperature. Discard developer solutions; wash tank, films clips, reels hangers, etc. Prepare fresh developer. Ensure that film clips, reels hangers, etc are thoroughly washed in hot water each time after use Mask has excessive green bias (high cyan and yellow mask values) Light fogging from red safe light or red indicator lights on equipment Undertake the development and bleach stages in total darkness High Contrast Values Over-agitation of the developer Decrease nitrogen burst - 2 -
Low Contrast Values Under-agitation of the developer Check nitrogen burst for action and increase if necessary High green contrast Over-concentration of the developer caused by evaporation Dilute developer with water High mask values mainly in the blue Exhausted rinse/stabilizer Replace with fresh Muddy appearance and high D Min. 1) Under replenishment fixer 2) Inadequate washing of film before fixer bath 3) Fixer mixing error 4) Low fixer temperature 1) Increase replenishment 2) Increase wash water change rate 3) Discard tank solution and prepare fresh 4) Increase temperature High Retained Silver and Low Leuco Cyan Dye (BP) Values 1) Underactive bleach, caused by inadequate bleach time, underreplenishment of bleach, insufficient aeration of bleach tank solution, incorrect preparation or faulty regeneration 2) Over replenishment of bleach 3) Over concentration of bleach tank solution due to evaporation 4) Low ph value of bleach. See recommended No. 1-4 in High Retained Silver (YP) Values 2) Reduce replenishment rate 3) Add water to the bleach to compensate for evaporation 4) Add Bleach Starter Spots or Streaks on Dry Processed Films 1) Inadequate water flow rate in wash tank between fixer and stabilizer 2) Under-replenishment or dirty stabilizer tank solution 3) Stabilizer tank solution not replaced at least once per week 4) Dust in dryer air flow or excessive dryer temperature 5) Over concentrated stabilizer tank solution 1) Discard water in tank and refill; increase rate of water flow 2) Discard stabilizer and prepare fresh 3) Discard stabilizer and prepare fresh; ensure solution replaced once per week 4) Replace dryer filter or move films to a cleaner area; reduce dryer temperature 5) Discard stabilizer solution and prepare fresh according to the recommendations - 3 -
RA-4 Print Systems High Blue Stain Level 1) Inadequate washing 2) Exhausted stabilizer/rinse 3) Exhausted bleach fix. 1) Check flow rate/temperature of wash 2) Replace stabilizer/rinse 3) Replace solution with fresh solution and check replenishment system; increase replenishment rate. Yellow streaking Light fogging Investigate cause and eliminate High speed, particularly blue plot Low speed, particularly blue plot Very high red and green Over-replenishment in developer Under replenishment in developer Bleach fix contamination of developer Decrease replenishment rate; add starter to working tank. Increase replenishment rate; add replenisher to working tank Replace developer with fresh tank solution High green HD level Over concentrated developer caused by evaporation Replace part of the developer working tank with water Manufactured by: CHAMPION PHOTOCHEMISTRY LIMITED 1700 Courtneypark Drive, Mississauga, Ontario L5T 1W1 Toll Free 1-800-387-3430 Tel (905) 670-7900 Fax (905) 670-2581 10/99-4 -
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