pH of Developer?

[Scott Wainer]

Hello all,

I'm just getting back to film after a long hiatus and have been looking for a developer with a long shelf-life that will work well with slow and medium speed films and provide ease of use, high acutance, and good highlight compensation. Previously I used D-76 then Xtol (both at 1+3 for greater sharpness and highlight compensation). After a lot of research I came up with a hybrid based on D-76 and Pat Gainer's PC-Glycol.

I converted the metol and hydroquinone to phenidone and ascorbic acid, dropped the sodium sulfite, and adjusted the quantity of borax (for the pH drop from the ascorbic acid). I mixed the developing agents in propylene glycol for longer shelf-life and add the borax at time of development. (Side note: I tried disolving the developing agents in 1000 ml of propylene glycol but after 2 days they separated back out of solution - with 2000 ml they stay in solution but I have to double the quantity to get the same amount of chemical.)

Part A (stock strength)
Phenidone 2.5 gm
Ascorbic Acid 100 gm
Propylene Glycol 2000 ml

Part B (working strength)
Borax 1 gm
Distilled water 960 ml

I use 40 ml of Part A + 960 ml of Part B to make up 1000 ml of developer for 1 - 36exp roll of film. This works out to roughly the equivalent of D-76 at 1+3 using 250 ml of stock developer.

My development times in a small tank for 35mm TTL metering have been:

Efke KB25
EI 25 10.00m @ 68F normal agitation
EI 25 15.00m @ 68F minimal agitation

Ilford PanF+
EI 50 12.50m @ 68F normal agitation
EI 50 18.75m @ 68F minimal agitation

Arista.EDU 100
EI 100 15.50m @ 68F normal agitation
EI 100 23.50m @ 68F minimal agitation

I get low fog, good shadow and highlight separation, good contrast, and very sharp even at 16x20 from 35mm film.

Now to the crux of my post:

From the sources I have been able to find, I know that the pH of the chemistry is:

9.5 Borax (0.1% solution)
2.5 Ascorbic Acid (5% solution)
??? Phenidone
??? Propylene Glycol
7.0 Distilled water (assumed)

Does anyone know of a way to figure the approximate pH of the working strength developer short of having to buy and maintain a pH meter? This is just for my information - it really doesn't make any difference.

 

[Photo Engineer]

The easiest way is to measure it. The calculations for that mix would be tedious if not impossible due to the organics present. I'm going to make a guess of about 9.5 though.

PE

 

[Scott Wainer]

Thank you PE.

The reason for my interest is that I have seen a lot of mention concerning pH of developers in regards to acutance (perceived and physical), grain, and gradation. I'm looking to increase acutance as much as possible while still maintaining the grain structure of the film and smooth gradation. I chose this formula thinking that a mild alkali (borax) will increase development time (therefore increasing adjacency effects - sharpness) and reduce the possibility of grain clumping (which I read can occur at high pH levels). I also dropped the sodium sulfite from the formula because I read that it is primarily a preservative (which the propylene glycol does) but will smooth (etch) the grain and replete the silver back to the film. I have also read conflicting accounts that it can lower and increase film speed. Could you elaborate any on this or recommend any changes I might try?

I was hoping not to have to buy and maintain a pH meter but I am really interested in what the pH is. Perhaps you could recommend an inexpensive one that is easy to maintain.

Thank you in advance.

 

[Trask]

If by "replete the silver back to the film" you mean redeposit the silver in solution back on the film, I wouldn't necessarily consider that a bad thing. I'm attaching a photo made on Arista 400, usually considered a fairly grainy film, developed in D-76 with added Aluminum Chloride, which has the effect of plating the silver back on the image. I hope you'll agree that the grain is good and the tonality is acceptable. (Photo made with Minolta SRT-101 with 85mm f/1.8 Rokkor, I believe.)

 

[Scott Wainer]

Trask,

In some cases it might be desirable, but what I was talking about was concerning an article written by Ed Buffaloe on the unblinkingeye website which was about adding sodium sulfite to Rodinal. In the article ( http://unblinkingeye.com/Articles/Rodinal/rodinal.html) he states:

"In high concentrations, sodium sulfite (the most-used preservative in photographic formulas) is said to literally eat away the sharp edges of silver grains in the developing emulsion. The dissolved silver is then available to be plated back onto developed silver grains in a process known as physical development. Physical development tends to blur the sharp edges of silver grains in the emulsion, reducing perceived sharpness."

Plating (and possible blurring of sharp edges) is what I am trying to avoid. Since I use slow to medium speed films I am more concerned with sharpness than fine grain (as these films already have very fine grain to begin with). It is my understanding that faster films produce greater perceived sharpness by the nature of their design even with more grain. I also read in a post (which I can't find right now) from this site (?) that plating of silver back onto the film can effect film speed by decreasing it. Since I am already shooting slow, fine grain 35mm film I want as much speed as possible.

On my screen and at the size i'm viewing it, it looks sharp with good tonality but not having seen the print in person I can't really comment further.

My need is based on grain-less images shot on 35mm film and enlarged to 11x14 or 16x20.

 

[Photo Engineer]

Scott;

First, grain clumping is a total myth! No one can show that it takes place. Read the very divisive threads on this matter here on APUG or read the literature on this. Increasing pH does increase grain, but by other methods, and Sulfite is not all bad!

Trask has some very good points in his post. Low pH may NOT be your desired route. It lowers contrast as well as having other effects. I suggest that you can't get there from here with just one test. This type of work requires months of R&D.

PE

 

[Jordan]

In reality, the only significant contributors to the pH of your solution are borax and ascorbic acid. But I agree with PE that finding someone with a pH meter would be much, much easier than trying to do a calculation based on acidity constants.

 

[Trask]

It is true that the process I use with Aluminum Chloride requires halving the ASA -- or to put it another way, doubling your exposure so as to "overexpose."

 

[eclarke]

Buy some litmus paper..EC

Hello all,

I'm just getting back to film after a long hiatus and have been looking for a developer with a long shelf-life that will work well with slow and medium speed films and provide ease of use, high acutance, and good highlight compensation. Previously I used D-76 then Xtol (both at 1+3 for greater sharpness and highlight compensation). After a lot of research I came up with a hybrid based on D-76 and Pat Gainer's PC-Glycol.

I converted the metol and hydroquinone to phenidone and ascorbic acid, dropped the sodium sulfite, and adjusted the quantity of borax (for the pH drop from the ascorbic acid). I mixed the developing agents in propylene glycol for longer shelf-life and add the borax at time of development. (Side note: I tried disolving the developing agents in 1000 ml of propylene glycol but after 2 days they separated back out of solution - with 2000 ml they stay in solution but I have to double the quantity to get the same amount of chemical.)

Part A (stock strength)
Phenidone 2.5 gm
Ascorbic Acid 100 gm
Propylene Glycol 2000 ml

Part B (working strength)
Borax 1 gm
Distilled water 960 ml

I use 40 ml of Part A + 960 ml of Part B to make up 1000 ml of developer for 1 - 36exp roll of film. This works out to roughly the equivalent of D-76 at 1+3 using 250 ml of stock developer.

My development times in a small tank for 35mm TTL metering have been:

Efke KB25
EI 25 10.00m @ 68F normal agitation
EI 25 15.00m @ 68F minimal agitation

Ilford PanF+
EI 50 12.50m @ 68F normal agitation
EI 50 18.75m @ 68F minimal agitation

Arista.EDU 100
EI 100 15.50m @ 68F normal agitation
EI 100 23.50m @ 68F minimal agitation

I get low fog, good shadow and highlight separation, good contrast, and very sharp even at 16x20 from 35mm film.

Now to the crux of my post:

From the sources I have been able to find, I know that the pH of the chemistry is:

9.5 Borax (0.1% solution)
2.5 Ascorbic Acid (5% solution)
??? Phenidone
??? Propylene Glycol
7.0 Distilled water (assumed)

Does anyone know of a way to figure the approximate pH of the working strength developer short of having to buy and maintain a pH meter? This is just for my information - it really doesn't make any difference.

 

[Ian Grant]

If by "replete the silver back to the film" you mean redeposit the silver in solution back on the film, I wouldn't necessarily consider that a bad thing. I'm attaching a photo made on Arista 400, usually considered a fairly grainy film, developed in D-76 with added Aluminum Chloride, which has the effect of plating the silver back on the image. I hope you'll agree that the grain is good and the tonality is acceptable. (Photo made with Minolta SRT-101 with 85mm f/1.8 Rokkor, I believe.)

Not sure where the Aluminium Chloride idea comes from, Kodak used Ammonium Chloride in D76 to give a fine grain developer, this was part of a series of experimental developers.

Around the time Ilford launched Perceptol they released a Technical sheet P10 which was essentially a short overview of different types of extra fine grain developers, they suggested adding 20gm Ammonium Chloride per 500 ml working solution of ID-11 (D76), with a doubling of development times and half the film speed.

Microdol-X and Perceptol use Sodium Chloride and there's no reason it can't be added to ID-11/D76.

Ian

 

[Alan Johnson]

I would suggest get some Hydrion pH paper (available in single rolls on Ebay) that covers the range including 9-10. I use the range 1 to 12 type, it gives the pH within about half a unit for most developers.

 

[Trask]

As Ian noted, it was my mistake to say Aluminum Chloride -- I should have written Ammonium Chloride. In fact, if you look at this posting you'll see that I had it correct back in 2008, and we benefit from Ian's insights as well:

(there was a url link here which no longer exists)

Here's the citation: "Chemical-physical D76: the addition of 40g/liter of ammonium chloride causes D76 to behave partly as a physical developer: silver dissolved from the emulsion is redeposited on the developing image as exceedingly minute particles and the (medium-speed film) negative will be virtually grainless. Reduce preferred EI ratings by 50%; increase development to twice normal."

 

[Scott Wainer]

PE and all,

My thoughts on sulfite were based on reading the section on Non-Solvent Developer in The Film Developer's Cookbook. Basically, I do not use it because it is a preservitave and I am using propylene glycol for that. It said that sulfite preserves the developing agents and reduces adjacency effects created by partially exhausted developer. I also want to avoid changing the grain structure of the film and making the fine grain films any finer due to a lack of sharpness associated solvent developers. Am I correct in my understanding? I know that there is much more going on here and that there are always conflicting data and lines of thought. Not having a background in chemistry (I did very poorly at it in high school) I feel like i'm taking bits from here and there and trying to put something together.

When I started with this developer my intent was a low contrast, high acutance developer that gave box speed or better with slow speed films (some of which have been labeled as contrasty) and had a very long shelf-life. Having tried numerous developers (D-76, Xtol, FX-37, and Pyrocat) which never gave me close to box speed and some of which died unexpectantly, I decided to formulate my own. Reading The Film Developer's Cookbook and various articles on the web gave rise to the formulation I came up with. I ran a series of film speed tests and found that I was getting average readings of 0.12 for Zone I and 1.37 for Zone VIII using the normal development times listed in my original post. Using minimal agitation I was getting readings of 0.14 and 1.22 which I was never able to achieve with D-76 or Xtol (I usually rated the film 1 stop lower which with Efke KB25 was a problem if there was any wind). I know that densitometer tests don't translate well to real-life situations so I shot several rolls at box speed with TTL metering of various scenes on a cloudy, bright day and developed them normally the same as for my film speed tests. I printed the negatives and got very nice shadow and highlight detail, fine grain, and very good acutance on 11x14 paper at grade 2-1/2. Comparing them to what I was getting there is a world of difference (all for the better) but I would like to increase the acutance even more without changing the grain, contrast, or tonality very much. Any ideas?


Alan,

I took your advice and ordered a vile of the 80-4800 strips (1-12 range) from sciencelab.com (http://www.sciencelab.com/page/S/PVAR/23669/80-4800). Are these the ones you are talking about?

 

[Photo Engineer]

I've always said that if it works for you, use it. I would not have done it the way you did, but if it works, that is what matters.

PE

 

[Alan Johnson]

The pH paper you ordered should be adequate.They also make rolls of pH 1-12 color coded at 1 pH intervals, slightly better but not on ebay when I looked.
The approximate pH of some moderate acutance developer working solutions I have measured:
Ilfosol S 9.3; FX-37 9.5; DS-2 9.8.
To increase the acutance (and grain) obtained with your developer try increasing the pH, eg by adding a little sodium carbonate to the B solution, it will not,of course,dissolve in propylene glycol.

 

[nworth]

I note that you have intentionally omitted sodium sulfite in your developers, and that you are using the acidity of the ascorbic acid to keep the pH low in Solution A. Sulfite does some good things in developers, however, and is probably a more effective preservative than ascorbate. One trick used fairly often to get longer shelf life is to mix the developing agents in water with a reasonable amount of sodium bisulfite. The bisulfite acts like sulfite as a preservative but also keeps the pH down. This solution does not last as long as a good glycol or TEA based developer, but it lasts quite well and is easier to make. The second solution contains the balance of the sulfite you might want and the alkali. You might have to go to metaborate as an alkali. You juggle the quantities so that the pH of the final developer solution will be right. You might also investigate TEA based developers. The pH is higher when mixed, but the results are quite good.

Incidentally, decent (not great) pH meters are available pretty cheaply from a number of sources. Be sure to pick up pH 4, 7, and 10 buffers to calibrate the pH meter if you get one.

 

[Gerald C Koch]

Part A (stock strength)
Phenidone 2.5 gm
Ascorbic Acid 100 gm
Propylene Glycol 2000 ml

I would suggest replacing the 2000 ml of glycol with 1000 ml of triethanolamine and eliminating Part B. In this variation the TEA produces the necessary pH and eliminates the need for borax. This yields a single solution concentrate. There is a very long thread on APUG about similar mixtures. You can fine tune the pH of the working developer by using a mixture of TEA and glycol.

Typically developers contain potassium bromide as a restrainer to prevent fog but it is insoluble in organic solvents. However it can be replaced with a small amount of benzotriazole.

There is a very long thread on such glycol developers on APUG. I would search using Gainer and glycol as key words.

 

[Scott Wainer]

Nworth / Gerald,

I read quite a few articles on TEA and glycol which was what drew my attention to them as a preservative for the developing agents. Reading Gainer's article "Preservation of Ascorbate Developers" on the unblinkingeye website sort of sealed the deal since I had a bottle of glycol on hand. I didn't go with TEA at the time as I didn't want to add yet another chemical to my closet but I may try it out. I do like the sound of a single solution developer.

My main concern with the sulfite is that I want to maximize adjacency effects in order to increase sharpness. I read in The Film Developer's Cookbook and other places on the web that sulfite reduces adjacency effects created exhaustion of the developing agents and smooths the edges of the silver grains; both of which lead to less sharp images. That is also why I chose borax as the alkali; thinking that it would exhaust faster as it is poorly buffered at high dilutions (i think that was from The Darkroom Cookbook). From what I have read metaborate and carbonate are better buffered at higher dilutions. Is that true?

So far I haven't seen much fog and want full box speed so I am loath to use a restrainer. For Efke KB25, the undeveloped but fixed film is reading about 0.21 and the clear part of the developed film is reading about 0.24.

I'll definitely search the site. Thank you.


Alan,

Thank you.

 

[Scott Wainer]

Are there different grades of Triethanolamine?

Has anyone bought Triethanolamine from thechemistrystore.com? I see they have it rather cheap compared to Photographer's Formulary and Artcraft Chemicals.

Here is the link: http://www.chemistrystore.com/Chemicals_S_Z-Triethanolamine.html

BTW, this is where I get my glycol.

 

[Photo Engineer]

There are several grades of TEA. This is based upon fundamental purity and also on the amount of DEA and MEA present in the TEA. These affect the pH of the solution that can be mixed by a given amount and also the Silver Halide solvent capabilities or tendencies. TEA varies from clear to yellow to brown depending on grade and it can be a liquid or a solid at about 20 deg C.

PE

 

[Scott Wainer]

PE,

Looking further I see that the TEA The Chemistry Store sells has CAS# 102-71-6. When I searched the CAS# MSDS it is listed as 99-100% and is listed as colorless to light yellow but there is no mention of DEA or MEA. Am I right in assuming this is of high purity and is sufficent for photographic use?

 

[Photo Engineer]

I would guess that to be true, but I cannot say. I have seen TEA shipped under that CAS#, expectedly 99% pure, and it reeked of amines and was a dark yellow brown slush. It was returned.

OTOH, I have seen a canary yellow version that made better developers than one that was water clear. So, it depends on "truth in advertising", age, and a number of factors including the developer formula. That "truth" comment is no slur on the seller (retailer) or even the wholesaler, but rather on the chemical company that is producing the material. In large amounts, TEA and similar chemicals tend to stratify and form layers and the overall purity may not be "your layer". Also, separating DEA, TEA and MEA is difficult. So, just beware. I have had no problem with paper developers nor have I heard of any, but I have had problems and have heard of problems with film developers.

PE

 

[Alan Johnson]

If you search for Gainer Chemistry Store TEA it appears Pat Gainer approved this product.
However,PC-TEA only has a pH about 9 and loses about half a stop in speed compared to DS-2,pH=9.8.
For higher emulsion speed your original approach was better IMO.

 

[Gerald C Koch]

Are there different grades of Triethanolamine?

Has anyone bought Triethanolamine from thechemistrystore.com? I see they have it rather cheap compared to Photographer's Formulary and Artcraft Chemicals.

Here is the link: http://www.chemistrystore.com/Chemicals_S_Z-Triethanolamine.html

BTW, this is where I get my glycol.

I bought a gallon of TEA from the chemistry store and it was clear and water white with no smell. Got very good results from it. They don't sell DEA or MEA as their primary clients are into making soap, lotions, and other personal products. Also got propylene glycol, Triton X-100, sodium sulfite, sodium carbonate, various pyrophosphate sequestering agents, and hypo from them.

 

[Scott Wainer]

Thank you all so much. You have given me a lot to think about. And we seemed to have strayed a bit (happily) from the thrust of my original post.

While I like the idea of a single solution (with TEA), one of my main criteria is maximum film speed and anything that might inhibit that is not very appealing. One day I may give it a try but for now I think I'll concentrate on traditional alkali. I have on hand sodium metaborate, sodium carbonate, and sodium hydroxide. I'll give these a try and see if I like what they give me any better than the borax. The proof will be in the prints.

Thank you again.