D-23 dilution, replenishment.

[markbau]

So I've decided to give D-23 a go for a while. I've not had highlights like I get with D-23 since I was using PMK regularly.

I could use it undiluted. Mixing up to make 500ml each time but I'd like to try it 1:1 but have a few questions.
The formula I'm using is from the Cookbook:
Water 750ml
Metol 7.5g
Sulphite 100g
WTM 1000ml

I've been halving the above:
Water 375ml
Metol 3.75g
Sulphite 50g
WTM 500ml

If I wanted to do 1:1 would I halve again?
Water 188ml
Metol 1.9g
Sulphite 25g
WTM 250ml which I would then add to 250ml water to make 500ml working.
Would there be enough Metal for a roll of film or should I just mix up 500ml stock and add it to 500ml water?

If I wanted to try replenishment where would I start? Would I only replenish stock or could I replenish 1:1? How would I replenish?

 

[Donald Qualls]

Why not just mix a liter or two and dilute from the stock solution? It'll save you time when you're processing, and the stuff will keep for a couple months even in a partially filled jar with no particular effort to exclude air (I speak from experience).

Replenishment should be done only with stock solution -- you'll develop in the stock, add the correct amount of replenisher for the film area you've processed into the storage bottle, and discard whatever working solution won't fit back into the same full storage bottle. DK-25R is the correct replenisher, and it's got a couple additional ingredients -- sodium metaborate (which can be purchased, or made in solution with the correct proportion of borax and sodium hydroxide) and potassium bromide.

The rule of thumb is to mix the same volume of replenisher as developer stock, and when you've used up the replenisher, discard the stock solution and start over fresh.

 

[pentaxuser]

markbau have a look at the Pictorial Planet video on D23 Replenishment. Here it is



pentaxuser

 

[markbau]

markbau have a look at the Pictorial Planet video on D23 Replenishment. Here it is



pentaxuser

Many thanks for the link, he explains replenishment very well. Replenished developer are said to have qualities that unreplenished developers do not have although I've never had it explained exactly what is going on, can anyone explain?

 

[Donald Qualls]

The primary special quality of replenished developer is economy. That's why replenishment was developed in the first place.

Beyond that, you get workers claiming all sort of miraculous qualities to the negatives, but I wonder how much of that is the equivalent of placebo effect. Certainly possible some of that is due to using stock solution strength instead of diluted developers, of course (using stock solution one-shot gets expensive by comparison).

 

[markbau]

The primary special quality of replenished developer is economy. That's why replenishment was developed in the first place.

Beyond that, you get workers claiming all sort of miraculous qualities to the negatives, but I wonder how much of that is the equivalent of placebo effect. Certainly possible some of that is due to using stock solution strength instead of diluted developers, of course (using stock solution one-shot gets expensive by comparison).

Indeed, Mr Finch claims "Replenishment makes for finer grain and sharper negatives." with replenishment. I'll have to dig out Henry's book and see if he tested this theory.

 

[Donald Qualls]

When I was using replenished D-23, I thought the grain was mushy in my scans at 1200 ppi. Didn't have any complaints with the sharpness, that I recall, though.

 

[pentaxuser]

Indeed, Mr Finch claims "Replenishment makes for finer grain and sharper negatives." with replenishment. .

I didn't recall where he may have said this so I listened again and unless it escaped me I didn't notice where he said this. Can you give me a time for this?

Thanks

pentaxuser

 

[markbau]

I didn't recall where he may have said this so I listened again and unless it escaped me I didn't notice where he said this. Can you give me a time for this?

Thanks

pentaxuser

He says it in reply to a question under the video.

 

[tokam]

I'm very tempted to go down this path as the cost of retail 1 litre packs of D-76 / ID11 / Perceptol in Australia is getting out of hand $16.00 +. I don't want a 5 litre batch of developer hanging around for ages.

With the same ingredients with the addition of Sodium Chloride you can make a developer supposedly with similar properties to Perceptol and Microdol-X. Worth investigating for little additional cost.

 

[Mr Bill]

Replenished developer are said to have qualities that unreplenished developers do not have although I've never had it explained exactly what is going on, can anyone explain?

Hi, I've never seriously looked into one of these systems but do have substantial experience with other replenished systems, primarily color negative and paper. So I can probably point out a few pertinent things.

First, this is not what I would call a "proper" replenished system. If it was "proper," one would not expect to see a difference in the processing.

Let me explain what is not "proper" about it. B&W photographic films mainly use silver bromide for the light-sensitive part. When it is exposed to light, and then developed, we end up with metallic silver in the film, and bromide ion is released in the developer. This bromide ion is a "restrainer" for developers (different developing agents may be more or less sensitive to this). Now, a "proper" replenished system should be able to restore the used developer solution back to the same chemical specifications (the formula) as the original. Regarding the bromide in the used developer, we are now stuck with it - at least some of it. We can dilute it down somewhat with replenisher, but since the original formula has NO bromide in it, it will NOT be possible, through the use of a replenisher addition, to fully restore the original chemical specs. Thus my position that this is not a "proper" replenished system.

Things are a little more complicated than just this. There can be some other byproducts released as the film is developed. But bromide ion is probably the main thing, along with small amounts of iodide ion from "modern" films. And this is likely one of the main reasons why the replenished developer might give slightly different results than the unreplenished versions. But as I've said, I've never specifically studied this one, so can't say for sure.

You might wonder, how is it possible to ever make a proper replenished system? Basically you would design the original developer solution with some amount of "byproducts" already in it. (You might wanf to make this developer more "active," somehow, perhaps a higher pH, etc., or perhaps just use a longer developing time, etc.) Then you would design the replenisher so that the added volume exactly counteracts the the amount of byproducts released. You would also have the replenisher be somewhat over-concentrated with respect to the developing agent, so as to compensate for that which is used up. This is basically how all of the color developers are designed. Professional b&w developers for machine use, have, in the past, also been made the same way. But these have never been well known on internet forums.

Hopefully this will shed a little light on things.

 

[RalphLambrecht]

Why not just mix a liter or two and dilute from the stock solution? It'll save you time when you're processing, and the stuff will keep for a couple months even in a partially filled jar with no particular effort to exclude air (I speak from experience).

Replenishment should be done only with stock solution -- you'll develop in the stock, add the correct amount of replenisher for the film area you've processed into the storage bottle, and discard whatever working solution won't fit back into the same full storage bottle. DK-25R is the correct replenisher, and it's got a couple additional ingredients -- sodium metaborate (which can be purchased, or made in solution with the correct proportion of borax and sodium hydroxide) and potassium bromide.

The rule of thumb is to mix the same volume of replenisher as developer stock, and when you've used up the replenisher, discard the stock solution and start over fresh.

+1

 

[markbau]

Hi, I've never seriously looked into one of these systems but do have substantial experience with other replenished systems, primarily color negative and paper. So I can probably point out a few pertinent things.

First, this is not what I would call a "proper" replenished system. If it was "proper," one would not expect to see a difference in the processing.

Let me explain what is not "proper" about it. B&W photographic films mainly use silver bromide for the light-sensitive part. When it is exposed to light, and then developed, we end up with metallic silver in the film, and bromide ion is released in the developer. This bromide ion is a "restrainer" for developers (different developing agents may be more or less sensitive to this). Now, a "proper" replenished system should be able to restore the used developer solution back to the same chemical specifications (the formula) as the original. Regarding the bromide in the used developer, we are now stuck with it - at least some of it. We can dilute it down somewhat with replenisher, but since the original formula has NO bromide in it, it will NOT be possible, through the use of a replenisher addition, to fully restore the original chemical specs. Thus my position that this is not a "proper" replenished system.

Things are a little more complicated than just this. There can be some other byproducts released as the film is developed. But bromide ion is probably the main thing, along with small amounts of iodide ion from "modern" films. And this is likely one of the main reasons why the replenished developer might give slightly different results than the unreplenished versions. But as I've said, I've never specifically studied this one, so can't say for sure.

You might wonder, how is it possible to ever make a proper replenished system? Basically you would design the original developer solution with some amount of "byproducts" already in it. (You might wanf to make this developer more "active," somehow, perhaps a higher pH, etc., or perhaps just use a longer developing time, etc.) Then you would design the replenisher so that the added volume exactly counteracts the the amount of byproducts released. You would also have the replenisher be somewhat over-concentrated with respect to the developing agent, so as to compensate for that which is used up. This is basically how all of the color developers are designed. Professional b&w developers for machine use, have, in the past, also been made the same way. But these have never been well known on internet forums.

Hopefully this will shed a little light on things.

Thanks so much for your fantastic explanation. What you said makes a lot of sense. It sounds like the mystical qualities replenishment promises are a bit like the mystical qualities of cold light heads. Just for fun I might replenish some D23 for a few films and then do a side by side with fresh stock.

 

[foc]

Professional b&w developers for machine use, have, in the past, also been made the same way. But these have never been well known on internet forums.

+1

Here is an example of Ilford Ilfotec DD & DD starter.

 

[Mr Bill]

Here is an example of Ilford Ilfotec DD & DD starter.

Thanks foc.

As a note to markbau, the significance of the "starter" in foc's post is that this is most likely adding "byproducts" to a developer working solution. Which suggests that it is most likely what I'd call a proper replenished system.

 

[Mr Bill]

Just for fun I might replenish some D23 for a few films and then do a side by side with fresh stock

Yeah, nothing like first-hand experience, provided you have enough control over the system.

Fwiw you might get a difference between the older technology films vs newer (that use some silver iodide). Also, as a note, your formula has quite a lot of sulfite in it, presumably enough to smooth out the grain a bit. So in single use you probably get full benefit of the sulfite. But... depending on your development method, this could change in a replenished system. If you use something that aerates a lot, such as a rotary processor, several processing runs MIGHT reduce the sulfite substantially. In such a case the grain MIGHT increase, due to loss of sulfite.

Again, I've never tested for these effects, just pointing out a possibility that should be kept in mind. Fwiw the sort of commercial processing machines that are replenished usually have minimal developer aeration, so this isn't an issue.

 

[MattKing]

FWIW, I do see a difference in the results obtained from replenished X-Tol vs. X-Tol used one shot, and I like that difference.
The presence of the restrainers referred to by Mr. Bill would inevitably change how any developer behaves. I expect that is what accounts for the "look" with my TMX, TMY and Plus-X negatives.
There are other advantages to replenishment besides economy, so I advocate it. For me, one of those advantages is the fact that replenished developer is particularly suitable for use at ambient temperatures, which is what I prefer, as I never have to adjust the temperature of my developer or fixer - I always use them at the ambient temperature.

 

[pentaxuser]

[QUOTE="MattKing, post: 2518267, member: 6437" For me, one of those advantages is the fact that replenished developer is particularly suitable for use at ambient temperatures, which is what I prefer, as I never have to adjust the temperature of my developer or fixer - I always use them at the ambient temperature.[/QUOTE]

Matt, do I take it that replenished developer does not need any adjustment for ambient temperatures? So today I use a replenishment developer at say 20C and tomorrow the ambient temp has changed to say 18C but I can use exactly the same time, whereas with a non replenished developer I would still have to adjust?

If I my interpretation of what you have said is correct then what is it about replenishment that eliminates this need for time variation as the ambient temp alters?

Thanks

 

[MattKing]

Matt, do I take it that replenished developer does not need any adjustment for ambient temperatures? So today I use a replenishment developer at say 20C and tomorrow the ambient temp has changed to say 18C but I can use exactly the same time, whereas with a non replenished developer I would still have to adjust?

Nope - I just adjust the development time to match the temperature - using the dial computer in my Kodak Darkroom Dataguide.
One like this:

 

[tokam]

Ilford also publish a temperature conversion chart. If you are developing at ambient temps you soon get used to the times for various combinations of film and developer, replenished or otherwise. I don't process outside of a range of 18C to 24C.

I hope you take notes and write them on the margins of your sheets of negatives. It is then easy to refer back to earlier films and see how you processed them. You may also want to make small adjustments to time and agitation based on earlier results. You'll soon fine tune your procedures. As the old saying goes 'It won't happen overnight....'.

 

[markbau]

Nope - I just adjust the development time to match the temperature - using the dial computer in my Kodak Darkroom Dataguide.
One like this:
View attachment 298199

But you can do that with any developer, Ilford and others publish the conversion charts. How is that an attribute of replenished developer?

 

[Donald Qualls]

I just yesterday watched John Finch's (Pictorial Planet on YouTube) video about replenishing D-23, and I'd forgotten (or never knew) two other related bits.

First, apparently one should develop three rolls (135-36, 120, or 8x10 equivalent of sheet film) per liter of stock solution without replenishment, to season the developer, approaching what will become the long term steady state condition; then, after using a set amount of replenisher (I recall this being the same volume as the original stock, but Finch recommended half that amount) one discards 3/4 of the replenished stock, refills with fresh stock, and continues with no further seasoning needed. This overcomes the byproduct build-up in a replenished system that doesn't add enough volume (as Xtol does) to keep buildup of bromides and oxidized developing agents under control.

And yes, the seasoning will surely require some small adjustment (10%?) to developing time to keep the contrast where it should be, but once seasoned, no further adjustment ought to be needed.

For temperature compensation, I've generally just applied 4% per degree F. This works well with Parodinal and D-23, in my experience, but two-agent developers can become nonlinear outside a reasonable range -- for instance, hydroquinone (I've read) becomes inactive rather suddenly as temperature drops below 60F, so the nature of the developer changes (superadditivity is lost) at that temperature. This may be partially credited for the use of cold development to manage age fogged film stocks, as it's my understanding that hydroquinone is also much more prone to fogging than metol or phenidone.

 

[pentaxuser]

Nope - I just adjust the development time to match the temperature - using the dial computer in my Kodak Darkroom Dataguide.
One like this:
View attachment 298199

Thanks Matt I clearly misunderstood what you said. It sounded as if replenishment has the advantage of freeing the user from adjusting development time compared to non-replenished developer but in fact the user has to adjust with either type based on the current ambient temperature so this is not one of the advantages of replenished developer compared to non-replenished

pentaxuser

 

[MattKing]

But you can do that with any developer, Ilford and others publish the conversion charts. How is that an attribute of replenished developer?

Replenished developer is re-used continuously, so the developer you are going to use (plus the replenisher you are going to add) is sitting there, at room temperature, always ready to go without any temperature control.
Other approaches require either temperature control while diluting stock or concentrate, or variation in development time as more and more films are developed in the same volume of stock, or the relatively un-economical one-shot use of pre-mixed stock developer.
The closest parallel to the work flow is probably some of the re-usable two bath options like Diafine.

 

[pentaxuser]

Replenished developer is re-used continuously, so the developer you are going to use (plus the replenisher you are going to add) is sitting there, at room temperature, always ready to go without any temperature control.
.

It may be likely that the replenisher stock for top-up sits in the same place as the replenished developer itself, namely the darkroom so both at the same ambient temp At least, this would be the case for me. The wife might be very unhappy if my replenisher stock sat anywhere else other than the darkroom

pentaxuser