Film developer replenishment

pentaxuser · Jan 2, 2025

Milpool said:
According to Kodak, D-23 stock solutions have the same keeping properties as D-76.

Incidentally there's good information on this (including keeping properties) in publication J-1. Regarding replenishment more generally, O-3 is another good reference.

Yes that was my impression as well and it may well be that I have not understood Don's reply He may mean that if you pour back used developer into the 1L container then you have to follow your regime and if you continue to pour it back but stick to the same time for each film you will find that D23 appears to lose strength.

However I'd like to understand exactly what he meant My initial interpretation of what he said was that remaining stock when you don't pour used developer back into the bottle but continue to use the developer as one shot still loses its strength quickly over a short time i.e. its keeping properties are poor

Whenever I see a statement that does not seem to accord with what I have previously written I always try to find out more about what may or may not be the respondent's experience

pentaxuser

Keith Tapscott. · Jan 3, 2025

I know that the OP has mentioned D23 replenished, but I remember reading about a modified replenisher for D76 consisting of 4 or 5 parts developer+ 1 part of D76R replenisher.
Does anyone know the correct formula for scratch mixing?

BobUK · Jan 3, 2025

Keith Tapscott.

The Kodak Chemicals and Formulas book I have does not mention the "4 or 5 parts developer + 1 part D76R."

It does say, add 30 ml of D76R per 8x10 sheet or equivalent processed.

D76R formula,
750ml water at 50c
Kodak Elon (Metol) 3g
Sodium Sulfite anhydrous. 100g
Hydroquinone 5g
Borax (Granular) 2g
water to make 1 litre

I am afraid I have not heard of the method you mentioned.

Don_ih · Jan 3, 2025

pentaxuser said:
Does the above statement indicate

That particular statement was about unreplenished D23 as it develops film. The lack of an alkaline in the developer makes its local developing activity different from what it would be in replenished D23, with lower agitation developing practices.

In terms of pouring used developer back into the stock and then reusuing it, I'd expect some minor amount of underdevelopment on the fourth roll for 1 litre of developer - major underdevelopment if those rolls were Tmax film. Tmax probably outright kills D23 after one roll.

Saganich said:
The pH may not be an important measure other than an indicator when you should mix up more.

The ph is not a great indicator of the viability of the developer, really. The developing agent (metol) can be completely overpowered by developer byproducts (iodide and bromide) and the ph can read just fine.

Keith Tapscott. · Jan 4, 2025

BobUK said:
Keith Tapscott.

The Kodak Chemicals and Formulas book I have does not mention the "4 or 5 parts developer + 1 part D76R."

It does say, add 30 ml of D76R per 8x10 sheet or equivalent processed.

D76R formula,
750ml water at 50c
Kodak Elon (Metol) 3g
Sodium Sulfite anhydrous. 100g
Hydroquinone 5g
Borax (Granular) 2g
water to make 1 litre

I am afraid I have not heard of the method you mentioned.

I've just looked up the publication.
The modified replenisher is mentioned in Kodak publication O-3 and consists of 5 parts developer and 1 part of the regular replenisher.

It's this modified replenisher that's recommended for replenishing Kodak TMax films, although I'm not sure why.
Kodak suggest adding 70ml of the modified replenisher for each 135-36 film and each 120 rollfilm.

Using rounded figures, the modified replenisher formula could be as follows.

Metol 2.2 grams
Sodium sulphite 100 grams
Hydroquinone 5.4 grams
Borax 5 grams.
Water to make 1 litre.

Perhaps someone can confirm this is correct.

Don_ih · Jan 4, 2025

Keith Tapscott. said:
It's this modified replenisher that's recommended for replenishing Kodak TMax films, although I'm not sure why.
Kodak suggest adding 70ml of the modified replenisher for each 135-36 film and each 120 rollfilm.

The byproducts left in the developer by Tmax films have a greater impact on the developer than those left by other films. I use other developers for Tmax films and the replenished D76 for Ilford films.

Milpool · Jan 4, 2025

Keith Tapscott. said:
I've just looked up the publication.
The modified replenisher is mentioned in Kodak publication O-3 and consists of 5 parts developer and 1 part of the regular replenisher.

It's this modified replenisher that's recommended for replenishing Kodak TMax films, although I'm not sure why.
Kodak suggest adding 70ml of the modified replenisher for each 135-36 film and each 120 rollfilm.

Using rounded figures, the modified replenisher formula could be as follows.

Metol 2.2 grams
Sodium sulphite 100 grams
Hydroquinone 5.4 grams
Borax 5 grams.
Water to make 1 litre.

Perhaps someone can confirm this is correct.

Keith, I think your math for the modified D-76R is correct.

In O-3 the description is more generalized - ie not T-Max specific but rather as an alternative to the normal D-76 replenishment regime if one wants to preserve full emulsion speed using replenished D-76. The D-76 tech pub (J-78) talks more about this alternative replenishment regime (capacity, keeping properties) and in that tech pub it is specifically in reference to the T-Max films. Essentially using the modified replenisher and regime is supposed to retain full emulsion speed and prevent an increase in contrast.

Basically it seems the idea is to use a weaker replenisher solution (not much different than stock D-76 with some extra buffering strength) but more of it.

Intuitively it makes sense although in practice I wonder how much difference it really makes. For example, the speed loss associated with running the replenished process - my guess is that is probably very small, likely too small to notice without careful measurements (ie the kind of processing monitoring pro labs would do when running large volume/replenished systems). That’s my two cents, at least.

Keith Tapscott. · Jan 4, 2025

Milpool said:
Keith, I think your math for the modified D-76R is correct.

In O-3 the description is more generalized - ie not T-Max specific but rather as an alternative to the normal D-76 replenishment regime if one wants to preserve full emulsion speed using replenished D-76. The D-76 tech pub (J-78) talks more about this alternative replenishment regime (capacity, keeping properties) and in that tech pub it is specifically in reference to the T-Max films. Essentially using the modified replenisher and regime is supposed to retain full emulsion speed and prevent an increase in contrast.

Basically it seems the idea is to use a weaker replenisher solution (not much different than stock D-76 with some extra buffering strength) but more of it.

Intuitively it makes sense although in practice I wonder how much difference it really makes. For example, the speed loss associated with running the replenished process - my guess is that is probably very small, likely too small to notice without careful measurements (ie the kind of processing monitoring pro labs would do when running large volume/replenished systems). That’s my two cents, at least.

Yes I agree. Although I don't use replenishment myself, I do enjoy reading about it.
I've always been a one shot user.

Don_ih · Jan 4, 2025

The modified replenisher is for use only with Tmax films.
From the D76 data sheet:

Note the last sentence above. And, from a bit farther down the page:

Keith Tapscott. · Jan 4, 2025

Don_ih said:
The modified replenisher is for use only with Tmax films.
From the D76 data sheet:

View attachment 386991

Note the last sentence above. And, from a bit farther down the page:

View attachment 386992

I see now that it's only for TMax films and the regular replenisher is for other films.

22.2 to 29.6ml for the regular replenisher averages out to 25.9ml, so I would probably start with 26ml if I decided on replenishment.
However, I will stick with the 1+1 one-shot method with D-76 or ID11 developers for optimum consistency.

Don_ih · Jan 4, 2025

I'm not particularly precious about how exact the development is, so I happily use D76 replenished. It comes out close enough to how I want it, I have no problem making prints, and the developer is always ready in the bottle. If I were a real stickler for consistency, I'd probably use whatever developer 1-shot. But I'm not. I don't expect every photo to be the same, so I'm fine with minor inconsistencies.

Truthfully, though, there aren't really any inconsistencies. It's very reliable.

Film developer replenishment

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