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c-41 color shift
It's been over twenty years since I worked in a lab so...
I've had some film developed at a local Costco a couple times in the last years (don't bother telling me I get what I pay for) I've noticed that the film they develop shifts blue when it's printed, even when it's printed at a different lab. I suspect that they are skimping on some replenishment, for all I know they don't even run controls. Any thoughts on what could cause a blue shift with c-41 chemistry? Paul |
#2
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c-41 color shift
Pdigmking wrote:
It's been over twenty years since I worked in a lab so... I've had some film developed at a local Costco a couple times in the last years (don't bother telling me I get what I pay for) I've noticed that the film they develop shifts blue when it's printed, even when it's printed at a different lab. I suspect that they are skimping on some replenishment, for all I know they don't even run controls. Any thoughts on what could cause a blue shift with c-41 chemistry? Paul A consistent blue shift in all frames of a roll of film could only mean a problem in the processing stage. Since the bleach and fix stages do not affect color, that would indicate a problem with the developer. C-41 should only be used once and then discarded. It is possible that your local Costco was trying to squeeze more than one usage out of the developer and that it was partially exhausted when used on your film. Do not despair of the film, however. Individual processing of the images can solve the printing problem. Machine processing makes assumptions about color balance, whereas a human being, seeing the blue shift can add a lot of cyan filtrationto eliminate the effect. Francis A. Miniter |
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c-41 color shift
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#4
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c-41 color shift
Pdigmking wrote: It's been over twenty years since I worked in a lab so... I've had some film developed at a local Costco a couple times in the last years (don't bother telling me I get what I pay for) I've noticed that the film they develop shifts blue when it's printed, even when it's printed at a different lab. I suspect that they are skimping on some replenishment, for all I know they don't even run controls. Any thoughts on what could cause a blue shift with c-41 chemistry? Paul It's highly unlikely the processing is off. More likely it's a problem with the film. |
#5
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c-41 color shift
wrote in message oups.com... Pdigmking wrote: It's been over twenty years since I worked in a lab so... I've had some film developed at a local Costco a couple times in the last years (don't bother telling me I get what I pay for) I've noticed that the film they develop shifts blue when it's printed, even when it's printed at a different lab. I suspect that they are skimping on some replenishment, for all I know they don't even run controls. Any thoughts on what could cause a blue shift with c-41 chemistry? Paul A consistent blue shift in all frames of a roll of film could only mean a problem in the processing stage. Since the bleach and fix stages do not affect color, that would indicate a problem with the developer. C-41 should only be used once and then discarded. Rubish! Comercial C-41 processing is designed to be replenished. The notion that a lab could run one film then retank is ridiculous. It is possible that your local Costco was trying to squeeze more than one usage out of the developer and that it was partially exhausted when used on your film. Why would they skimp on replenishment only to have to retank freqently at much higher cost? Do not despair of the film, however. Individual processing of the images can solve the printing problem. Machine processing makes assumptions about color balance, whereas a human being, seeing the blue shift can add a lot of cyan filtrationto eliminate the effect. How would adding cyan eliminate blue? The original poster should just go back to the lab and ask them to reprint a little warmer by adding a little yellow. The chances that this is a processing fault is quite slim and more likely to be a problem with the film stock or even print viewing conditions. -- Dooey |
#6
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c-41 color shift
Just have the negatives printed correctly. There's probably nothing wrong
with your film, just your lab technicians. Color isn't locked into a negative - it's interpreted every time it's printed. "Pdigmking" wrote in message ... It's been over twenty years since I worked in a lab so... I've had some film developed at a local Costco a couple times in the last years (don't bother telling me I get what I pay for) I've noticed that the film they develop shifts blue when it's printed, even when it's printed at a different lab. I suspect that they are skimping on some replenishment, for all I know they don't even run controls. Any thoughts on what could cause a blue shift with c-41 chemistry? Paul |
#7
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c-41 color shift
wrote in message oups.com... Pdigmking wrote: It's been over twenty years since I worked in a lab so... I've had some film developed at a local Costco a couple times in the last years (don't bother telling me I get what I pay for) I've noticed that the film they develop shifts blue when it's printed, even when it's printed at a different lab. I suspect that they are skimping on some replenishment, for all I know they don't even run controls. Any thoughts on what could cause a blue shift with c-41 chemistry? Paul A consistent blue shift in all frames of a roll of film could only mean a problem in the processing stage. Since the bleach and fix stages do not affect color, that would indicate a problem with the developer. C-41 should only be used once and then discarded. It is possible that your local Costco was trying to squeeze more than one usage out of the developer and that it was partially exhausted when used on your film. Do not despair of the film, however. Individual processing of the images can solve the printing problem. Machine processing makes assumptions about color balance, whereas a human being, seeing the blue shift can add a lot of cyan filtrationto eliminate the effect. Francis A. Miniter If the shadow/black areas of the prints have a bluish cast (kind of a "veil"), that could indicate weak RA-4 developer, or too low developer temperature. Have you tried taking the negs somewhere else to have them printed? Perhaps the local Costco is out of balance on their printer. (Kodak C-41 developer is available as either a one-shot, or a replenished version. I prefer the one-shot version for developer, fixer and stabilizer; the replenished version for bleach, because of the costs and the disposal. Bleach is a nastier disposal issue than the other chems.) (The opposite of blue is yellow, cyan is opposite red.) (Machine printing does make assumptions about color balance, but on a frame-by-frame basis. If all the frames are of a similar subject matter, then any 'imbalance' will probably follow the entire roll. If the frames have different subject matter, then color balances will be different for each differing frame.) -- Ken Hart |
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c-41 color shift
"Ken Hart" wrote If the shadow/black areas of the prints have a bluish cast (kind of a "veil"), that could indicate weak RA-4 developer, or too low developer temperature. True if the contrast is also very low. This could also be due to a weak exposure. But if the negs show a good density and the prints are just off color with a "natural" contrast range, the problem is most likely in the printing. |
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