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"Old Soup" versus "New Soup"


Eric Niemi

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Hello...

Hope everyone is safe and well during these trying times.

Had a question about the difference between having a lab run your film through old soup versus new soup.

Can anyone describe the possible differences in color and contrast that might occur.

Thanks so much ?

-Eric

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Thanks for the response :)

Sure. Sure. But was wondering what type of difference might occur if someone gets their film developed in an old bath versus fresh chemicals. Also, wondering would it be poor etiquette to simply ask a lab to call when they have a fresh batch of soup?

Really want to get as much as possible out of a Super 8mm project and simply want to weigh how much of a difference might exist if it gets sent through older chemicals.

I'm thinking Super 8mm might suffer more from an old bath than say 16mm or 35mm.

Any and all replies and opinions welcomed.

Thanks!

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I don't think a client can ask a lab to dump hundreds or thousands of dollars of chemicals just so that their footage can be developed in a fresh bath.  A decent lab is going to replenish their baths as needed. It's not a binary situation where either the bath is fresh or it's too old to give good results.

Modern color negative motion picture film is designed to be fairly robust, not hyper-sensitive to small development variations.

Obviously a poor lab that keeps using the same old bath past any recommendations by Kodak or whoever is going to give you less than optimal results. 

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Thanks for your response, David. Appreciated.

But puzzled that you thought I was suggesting a client ask a lab to dump their entire bath. Exact words were-

"Also, wondering would it be poor etiquette to simply ask a lab to call when they have a fresh batch of soup?"

In that sentence I make it clear that I was wondering if it would be considered poor etiquette to simply ask the lab to call when they have a fresh bath.

If a client is bringing in a lot of product. Maybe 200 rolls of Super 8mm. Would it be out of line to simply ask the lab to call when they have a fresh tank? I'm assuming they change chemicals at least once every few months or so... right?

Still hoping someone can answer my specific questions here.

What are the effects of old chemicals versus fresh? Color and contrast.

And is it out of sorts to simply ask for the lab to call when they have a fresh tank?

Thanks... 

 

 

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Eric, all labs running continuous film processors will replenish their tanks as film is being developed.
As well as that, they'll run control strips ( sensitometrically exposed film ) to monitor the process and make adjustments if needed.

It's a very precisely controlled action - and fine tuned as they go.
This technique ensures the process is far more in tolerance ( in control ) than you'll ever see by eye yourself.
It may surprise you to know most labs are using the 'same' chemicals they started with years ago ( but replenished and filtered all the time of course ).

Some smaller operators ( usually those without professional laboratory experience ) may work by using 'single shot' chemicals. Those operators by definition cannot properly control their processing lines. 

John S ?

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As John says, a well seasoned, replenished developer is also well controlled and predictable.

"New Soup" is hot, unbalanced and constantly varying;  it is typically "seasoned" with lab short ends and (in the past) things like leader stock that is not super critical for color or density.

You don't want "new soup"...

 

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4 hours ago, John Salim said:

Eric, all labs running continuous film processors will replenish their tanks as film is being developed.
As well as that, they'll run control strips ( sensitometrically exposed film ) to monitor the process and make adjustments if needed.

It's a very precisely controlled action - and fine tuned as they go.
This technique ensures the process is far more in tolerance ( in control ) than you'll ever see by eye yourself.
It may surprise you to know most labs are using the 'same' chemicals they started with years ago ( but replenished and filtered all the time of course ).

Some smaller operators ( usually those without professional laboratory experience ) may work by using 'single shot' chemicals. Those operators by definition cannot properly control their processing lines. 

John S ?

Oh wow. Thanks for this... John ?

I falsely assumed all baths had an expiration date of sorts kinda like when you buy a gallon of milk type of deal where the closer you get to expiration the lesser the quality.

This response is really appreciated.

Thanks!

 

Edited by Eric Niemi
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2 hours ago, Frank Wylie said:

As John says, a well seasoned, replenished developer is also well controlled and predictable.

"New Soup" is hot, unbalanced and constantly varying;  it is typically "seasoned" with lab short ends and (in the past) things like leader stock that is not super critical for color or density.

You don't want "new soup"...

 

Thanks, Frank ?

Very helpful explaining the chemistries here at work.

So it's kinda like chlorine in a pool maybe...? You don't want to really swim in the pool right after the Pool Technician adds chlorine but much better to simply hit the pool when the monitored levels are within spec type of deal.

Thanks for all the replies everyone. It corrected my misconceptions and hopefully will allay other people's fears too.

Best to simply head to a reputable lab and not overthink it type of deal.

Thanks!  

Edited by Eric Niemi
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There are many ingredients to a process and one tank may be exhausted i.e. bleach fix which needs to be de-silvered and the developer is fine. It is very rare that a whole machine's full chemistry will be all dumped and replaced at once.

We run a sensiometric control before each run and check it on the densitometer and adjust chemistry as needed to get it into the proper spec to run.

Also there is a metered replenishment fed into the various chemistry tanks to keep it at spec for the run.

In theory and in practice a sensiometric control strip run at the beginning of the run and one at the end will be practically the same numbers on the densitometer and day to day.

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