D76 One Shot

[MattKing]

What I've never understood is how Kodak makes commercial D-76 mix well with all the components poured in together. Normally, if you add too much sodium sulfite before the metol, the metol is hard to dissolve -- do they just get away with this via timing (only a little of the sulfite will dissolve before the metol goes into solution -- enough to prevent oxidation but not enough to affect solubility), or is there some special treatment of something?

Which, of course, has nothing to do with whether the first tablespoon from a bag of commercial D-76 powder has the same composition as the last...

That is the "secret sauce". A trade secret that permits single envelope packages, where Ilford is required to package ID-11 in two envelopes.
Back in the day, that was a huge commercial advantage.

 

[xkaes]

There's nothing stopping Kodak from adding something(s) to their recipe to make things dissolve better.

 

[removedacct1]

About making the components soluble as an "all in one bag" product: isn't that what the sequestering agent was doing?

 

[Don Heisz]

You realize this immediately, because the systems measure exactly how much of each component is delivered to the mixing container - a clogged nozzle will mean no measured delivery.

So another inefficient characteristic of what you describe.

 

[pentaxuser]

But when that method is used, the individual components are measured, and the total combination is not mixed in bulk - it is mixed as it is being "pumped" into the container that is then dumped into an individual bag.

Matt I have no idea who makes this stuff these days and really this doesn't matter as long as you can be sure that it is "mixed" exactly as you describe. If so my thinking, possibly flawed, is that we can be sure that the exact amount of the correct ingredients are delivered into each packet. Thus any other method such as scooping out only part of the pack does rely on luck to an extent to get the absolutely right portions onto only part of the pack

So I go back to my original thought that a thorough shake is the best way to ensure that the tablespoon gathers as near as make no difference the correct ingredients in the correct portions

However it seems to me that while a good shake should mix it correctly there is a chance it may not and we are back to the question of whether the tablespoon might miss enough of the least amount of ingredients, metol and borax to affect the negatives to the extent that they will be sufficiently different for negative developed in the exact amount of each ingredient

Kodak may have done tests on this in case users asked the obvious question about using only part of the packet but does anyone know if it did and if it published the results

I am trying to establish what facts we have that will result in an answer that might help those who are wondering about trying this method to know the facts

I have no vested interest in what the answer might be other than it helps users to decide whether this method will work and to what extent it might work

pentaxuser

 

[koraks]

Kodak may have done tests on this in case users asked the obvious question about using only part of the packet but does anyone know if it did and if it published the results

I doubt they actually did the tests, and I think if you call them and ask them about it, they'll just state to follow the directions on the package and that any deviation from that is at your own risk.

This is one of those things where if it works for someone, they shouldn't fuss about it and just be happy about it. We could sit here and discuss particle dynamics all day long, and it's not going to make anyone's photography any better.

 

[pentaxuser]

This is one of those things where if it works for someone, they shouldn't fuss about it and just be happy about it.

Yes but the crucial thing is will the scoop of a tablespoon work consistently every time or work well enough to get negatives that are consistent to the extent that prints from them will be very similar?

Maybe that is not what this thread is concerned about and this is of interest only to me but I was interested to try and find out if anyone has any information about how well the exactly delivered ingredients in the 1 and 5 L packs remain exactly in those portions when a tablespoon is scooped out

Maybe no-one knows the answer and this question will be condemned to keep being repeated at intervals with the same outcome each time in the same way the Flying Dutchman is condemned to sail the oceans eternally

pentaxuser

 

[Don Heisz]

will the scoop of a tablespoon work consistently every time or work well enough to get negatives that are consistent to the extent that prints from them will be very similar?

The Magic 8 Ball says "Yes".

 

[pentaxuser]

The Magic 8 Ball says "Yes".

View attachment 327311

To-date how many times has the tablespoon method worked for you Don? By "worked" I mean no noticeable difference in the negatives

It is clear that like many other threads on methods on Photrio we have the believers and the doubters and that's not a problem for either group. Each group or often it's two individuals will espouse their respective positions and after a few exchanges the thread dies

What I am trying to do is gather information in the thread that helps someone who has never tried the method but has an interest in it to decide what risks it might or might not run.

Thanks

pentaxuser

 

[Don Heisz]

To-date how many times has the tablespoon method worked for you Don? By "worked" I mean no noticeable difference in the negatives

I used a scale, not a spoon. And I went through between ten and fifteen gallon bags of D76 - around the same of Dektol - before I started just making my own developer. I only had a problem when I switched digital scales (my previous one broke) and discovered (by getting some underdeveloped rolls) that my new scale was not accurate.
I now use a triple beam balance and don't buy any prepackaged developers.

 

[momus]

Mods, feel free to merge this w/ the existing thread on D76 one shot. I thought it might be easier for people to find this on Foma 100 w/o having to go through all the comments on the Delta 100 thread, but that's up to you.

Pentax MV, 50 2 lens, no fltr, Foma 100 at EI 50, developed in D76 as a one shot developer. My tank holds 370 ml for one roll, so I increased the developer to 1 1/4 tbs vs Mike's formula for 1 tbs in a tank that only needs 300 ml developer.

D76 bag was opened and shaken like crazy, 1 1/4 tbs was scooped out, and the bag resealed tightly w/ no air pockets. I used 13 oz of hot water out of the tap, more serious shaking of the chemicals, and let it sit for an hr. It was still way too hot so I cooled it in a sink water bath to around 68-70 F. Developed for 6:20 minutes, constant agitation first 30 seconds, 2 gentle inversions thereafter, none the last 40 seconds or so. Scans are from a toy Wolverine scanner that does a fine job for web stuff, or proofs to see what is worth printing in the darkroom.

The light has been very subdued and overcast in Little Rock w/ all the rain we've been having, I need a Y. fltr out here. Next time it's being upped to 1 1/2 tbs of developer, I want to see some grain! The lousy light hasn't helped w/ that. This was my first try w/ Foma 100 in D76, I think Rodinal at 1:50 is the better developer for it.

 

[MattKing]

So as long as you get Don to do your mixing up of the bags before each "scoop", you can expect reasonable results .
There are lots of variables - including variability in tolerances from user to user.
Users need to decide for themselves whether the disadvantages of mixing up a gallon at a time are outweighed by the potential uncertainty.
As I've posted, it would make more sense for me to do this with a print developer than a film developer - that being merely an indication of where my risk tolerances are.

 

[pentaxuser]

"I've finished about 15 bags exactly that way - it went fine."

Don, thanks for the reply in #35. If I had paid more attention I would have realised you had already answered my question with your earlier quote above about finishing 15 bags with complete success That's impressive

So just to be clear: When using a scale what is the weight of D76 you used and was this for a 35 mm 120?

Can I take it that if the D76 instructions say how many films a 1L bag can do then you simply divide the total net weight of the pack by that number and remove that weight in powder from the pack?

As far as shaking as opposed to stirring is concerned, did you stir the powder each time before placing the correct weight onto the scales

How long did it take you to empty a bag this way? I ask that because higher volume users which might include you, might well get through a bag with your method in a short period of time that might be similar to the period for which a stock solution divided into say 250ml bottles would also last

In terms of the method ability to extend the life of D76 powder then ideally the period you exhausted one bag was much longer than you would expect stock solution to last in tightly capped 250ml bottles. In theory and as long as the powder can be kept sealed and then in a ziplock bag the answer to its longevity might be in months at worst or even years at best

Thanks

pentaxuser

 

[Don Heisz]

When using a scale what is the weight of D76 you used and was this for a 35 mm 120?

I don't remember the exact amount. You figure out how many g/ml of the powder would be in the stock solution (weight of bag in grams/3890) and multiply it by 500 to for 500ml of stock solution. Multiply it by 250 to get 500 ml of 1:1 solution. I just cut the corner off the bag and poured it into a muffin paper on a scale.

Matt is a little suspicious of things said by others.

 

[MattKing]

Matt is a little suspicious of things said by others.

Not in the least - or at least not with respect to what you are saying here.
I'm just leery of extending the particular into the general, when it comes to extrapolating experience that is directly contradictory from that which the manufacturer recommends.

 

[pentaxuser]

I don't remember the exact amount. You figure out how many g/ml of the powder would be in the stock solution (weight of bag in grams/3890) and multiply it by 500 to for 500ml of stock solution. Multiply it by 250 to get 500 ml of 1:1 solution. I just cut the corner off the bag and poured it into a muffin paper on a scale.

Matt is a little suspicious of things said by others.

Thanks, Don. Where does the 3890 figure come from and can you say what the time period was for emptying the whole bag? This method you used has distinct advantages for the low volume film user but to have that advantage, knowledge of how long it took you to use up the whole bag will help

pentaxuser

 

[MattKing]

Where does the 3890 figure come from

Probably the number of milliliters in a US gallon, although I would use 3,785

 

[Arvee]

Intrigued by this discussion, I decided to add my $ .02. Went into the DR and measured out the chemicals to brew a liter of 76 (1927 formula) into a 100 g PF plastic bottle which afforded me an airspace of 3X the volume of the powder mix. Agitated the bottle 30-40 times to mix well. Spooned out 2.5 level tsp into 250ml @ 18C and stirred for about 15-20 seconds. After stirring had a clear beaker, all chemicals dissolved at 18C. Immediately poured the developer into a 1 reel tank with 5 frames of UF Finesse exposed at ISO 400 and developed for 15 minutes at 18C, 4 inv./min, stopped, fixed and washed appropriately. Side by side comparison with a strip developed yesterday in Xtol 1:1 for 15 minutes at 18C found virtually identical densities for the same subject matter (eyeballed on a light table). The Xtol negs wet print very nicely on my Durst 601 with 2.5 filter so I would definitely expect that the 76 negs would also.
PS. My chemist wife reviewed the process for creating an homogeneous powder mix with me and offered the conclusion that it should be fine. It absolutely was!

My $ .02 worth toward the discussion...







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[pentaxuser]

Arvee, my thanks for your contribution which is supportive of the one shot method. I note that compared to the amount used in the much earlier link by a contributor called forfiv on another site, it appears that you had success with slightly less powder than he used which is great. His was about a tablespoon(15ml) which is 3 teaspoons but yours was 2.5 level teaspoons

My only question now is: Is the 1927 version of D76 that you used close enough to the modern commercial version of D76 for the same method and amounts of powder to be reliable?

I should add here that even if the versions are different it is still useful in that it demonstrates that using only a portion of the 1927 D76 may be valid so those who may be home chemists and use the amount of ingredients to make 1L have the option to use only enough for say one film at stock solution at a time

pentaxuser

 

[MattKing]

It is critically important to remember that home mixed D-76 won't have in it the things that allow commercial D-76 to be kept in a single bag - the special Kodak "secret sauce". As Ilford doesn't have access to that trade secret, their version (ID-11) needs to be packaged in two separate bags, not mixed together until both are added to water.
Home mixed D-76 will also most likely omit the components designed to deal with varying water sources - chelating agents being an example.
There is a lot of things in a bag of commercial D-76 that you won't find in and don't need in home mixed D-76. And those things aren't there loose in the bag - they are bound together in special combinations that make the single package possible.
So things like the particle size and weight will differ - meaning that the two may require different stirring techniques/efforts to try to ensure homogeneity.
And by the way, home mixed D-76 powder should be relatively unstable - it should start slowly reacting with itself immediately upon putting it together.
A single bag of D-76 has enough powder developer in it to develop 16 rolls of film. That is it - the value of trying to stretch that out past 6 months or so isn't particularly obvious.

 

[Arvee]

Pentaxuser: My experiment was sponsored by all the speculation in this thread. I decided that I should go ahead with actual preparation and development to see if the 'fears' expressed in this thread had merit. So, my advice to you is to follow my footprints and develop a few test frames and see if Matt's concerns are valid for your workflow and process.
I have always read that you cannot dissolve D-76 in room temperature water yet my mix cleared in a 20 seconds at 18C which flies in the face of the 125F rule. Also, the story about taking a small amount from a 1 gal packet will not be a proper chemical mix proportion seems to be more folklore based on my experiment. Photography is rife with folklore and myths founded on imaginative speculation.
So, grab your tsp measuring spoon and go for it; I'm betting it'll be just fine just like the fellow over on Flickr discovered. BTW, I did the math and used my jeweler's gram scale to confirm that 2.5 tsp (leveled) is close enough for 250ml working solution.
Let us know how your experiment progresses.

Edit: Also keep in mind that mfrs. product use instructions are always biased in favor of the consumer using the maximum reasonable volume of product so they can sell you more product.

 

[Kino]

I can see both sides of the argument being valid for their own circumstance.

The teaspoon measuring user will probably not notice any meaningful problems because it falls within levels of variation acceptable to that user.

Anyone who processes for extreme repeatability and consistent, sensitometry-confirmed results probably won't be happy with the teaspoon method, so they would be right to stick to the Kodak instructions.

There is value in being able to "bend the rules" by using tablespoons to meet personal objectives, but there is also value in the traditionalists warning of potential disaster.

As long as we consenting adults that take full responsibility for our own actions, we can use teaspoons or full bags at our on discretion.

 

[guangong]

It’s been a long time since I used D76, but as I remember, the instructions on label required mixing whole can at one time and not attempt to mix only a part of contents. The word “can” gives an idea how long ago I used D76.

 

[pentaxuser]

It is critically important to remember that home mixed D-76 won't have in it the things that allow commercial D-76 to be kept in a single bag - the special Kodak "secret sauce".

Yes, Matt, I did wonder if it would be suggested that the famous "secret sauce" might be like a Pandora's box , if "opened" and used "one shot"

However I think you are saying this may be the case as opposed to knowing it to be the case?

pentaxuser

 

[MattKing]

No, I'm saying that the steps necessary to ensure even mixing are not simple, and that the quality of the mixing - the homogeneity of the results - will differ because the particles in the bag will be of different size and shape and mixability then the home mixed stuff.
I was wandering through stuff on the internet yesterday about how to mix powders in order to ensure homogeneity. Not surprisingly, there are two main sources - pharmaceutical related materials, and materials related to home baking!
The home baking materials are, of course, a bit less precise, but even they emphasize how much care one needs to take. Shaking is not the way to do it - you need to stir and stir and stir and the bowl/container shape and size matters.
The pharmaceutical related materials are divided into two general types - directed to compounding pharmacists and related to drugs mixed and then put into capsules. The former compare several types of relatively high end pieces of equipment that use multiple techniques to ensure an even mix. The latter refer to equipment and methods that require hours of mixing.
The only source that I found that referenced dividing packages of photographic chemicals was a reddit discussion that somewhat mirrors this thread. One participant was a photographer who was also a chemist, whose emphatic position was that one cannot achieve enough consistency to do this. Another participant said that they tried this with a developer, the first three rolls developed "fine" while the last one came out blank. A couple of the other participants said they did it regularly, and had no problems.
A roll of T-Max 400 120 is $17.75 for me. A package of D-76 from the same source would be $12.33, if I used that developer. It is quite easy, convenient and practical to mix up a gallon of D-76 and divide it into a few smaller bottles. I would have to waste an awful lot of mixed up D-76 before the cost of that waste would equal the cost and value of one messed up roll of film.