Sunday, March 20, 2011

PCB-developer, letter from a correspondent.

This blog has received a very interesting mail:

I came across your blog (
which is very interesting. 

I am also into vitamin-c developers and use Caffenol-C and Phenidone-C developers exclusively. I also like that you try to be frugal with your developers as that means more money for film :-) I have been using different versions of Caffenol-C, particularly the ones from, have had good results with medium-speed (ISO 100) films, but mediocre results with high-speed (ISO 400) films. With high speed films (e.g. Tri-X) I find the tonality quite good but the difference in the grain is obvious and in my opinion can be intrusive. Overall, my results using Caffenol-C with Tri-X are okay but I do have other preferences and this is why I'm writing you, to tell you about another vitamin-c
developer which we'll call PCB (Phenidone / Vitamin C / Borax).
I came across this developer on APUG

and it piqued my interest as I have been using PC-Glycol

with borax for some time and have always used it one-shot. These developers behave like a cross between XTOL and D-76, both of which I like. 

This post proposes 1L of developer that can be re-used at least 12 times (I have tried 15 times with no noticeable change in activity) with simple ingredients. More importantly, the results I get with fast films are great ... very nice tonality, minimal grain (I use a Nikon Coolscan 9000 which seems to magnify grain), and full box speed. Using medium speed films (e.g. Plus-X) I can barely see the grain and using something like Acros I simply cannot see it.
The APUG post is not completely clear on all the details as it is part of a much longer thread so here are my notes that explain everything.

The PCB developer is as follows:

Borax saturate solution - 400ml
Ascorbic Acid - 6g
Phenidone - 0.15g
Water to make 1L
Use the same start times as D-76.
Phenidone - Because quantities of phenidone are so small it’s easier to make a percentage solution. 
Add 1g phenidone to 100ml propylene glycol to make a 1% solution. 
This will require heating to dissolve (15-30 seconds in the microwave should do it … heat in 10 second bursts then stir as you don’t want to over-heat, just enough to get phenidone in solution). 

Phenidone will keep indefinitely in propylene glycol provided there is no water. You will use 15ml of this to make a batch of developer. You can get phenidone from a chemical supplier or Photographers' Formulary. You can see that you don't need very much as 1g makes over 6L of re-usable developer. 

Propylene glycol is available at the pharmacy but you may have to ask the pharmacist for it.
Ascorbic Acid - Same concerns as with Caffenol-C. Make sure it's 100% pure ascorbic acid powder which can be obtained from a pharmacy or health food store.
Borax Saturate Solution : 
Add 200g borax and water to make 2L.

Agitate and/or slightly heat the water to get as much borax into
solution as possible. The borax will not completely dissolve. Let it
stand for a few hours and you will have a clear solution on the top
with excess borax on the bottom. 
The clear portion will be a saturate solution of 4.71% at 20C (this is what you use to make the developer).
Keep adding water to this solution as it is used and add borax as necessary so there is excess (if the borax is completely dissolved you no longer have a saturate solution and concentration will be less).

Replenishing the water and keeping excess borax will maintain a constant 4.71% saturate solution. Borax can be found in the laundry section of grocery/hardware stores, from Photographers' Formulary, or chemical suppliers.
I hope you try this developer as it is easy to make, easy to use, inexpensive, and works well with films where Caffenol does not. Keep up the good work with your blog.
Regards, Michael.

This answer from yours sincerely followed shortly :

Michael, I respectfully ask your permission to use your mail as an entry in the blog!
Preferably boosted by some of your pictures as examples, I think this is interesting and merits acknowledgement from others.....

Very interesting indeed, and it piques my interest too!
In fact that is WHY I named my blog ASCORBATE developers, to shift the focus from coffe, which is something I drink, to ascorbate(s) in a mix with other developing agents.

I have to be short, but feel free to mail me.

In closing I think you'll find that Cafenol C-L which is something that Reinhold touts on his blog, will give you finer grain, also in Tri X.
However, since Cafenol is a very fine grain, COMPENSATING developer, contrast tends to be lost with extended development time.

Personally I have had little success with Cofenol C-L, the negatives are so lacking in contrast that I need to Photoshop everything, how this would fare in a darkroom I can only speculate upon, since I no longer spend time in one!

Thats why I'm looking for alternatives, alternatives to coffe, which usually yelds extremely low contrast (I did a testrun with just soda and coffe which was unsatisfactory), and have been eyeballing Tylenol, but so far have not had time for my next big experiment!

Keep in touch and if you want it, I can set you up as a co-author on my blog aloso, where you could post whatever you like, as far as it is within the broad context of the blog, under your own name.

Keep burning film!


In a matter of minutes this answer landed in my in-box :

By all means, you can post this to your blog. I was just running some additional tests today to confirm some theories and have attached a few samples. They are both 35mm Tri-X with the "normal_dev" one exposed at EI 800 then developed for 8:45 (18C) with normal agitation and the "minimal_agitation" one exposed at EI 1600 then developed for
20:00 (18C) with minimal agitation (5 min pre-wet, 60 sec initial inversions, 10 sec inversions every 5 mins). I find that using minimal agitation when pushing creates a compensating effect that controls contrast and gives negatives that require little to no adjustments. The penalty for minimal agitation is more apparent grain which is still significantly less than my best results with Caffenol.

They were scanned with a Nikon Coolscan 9000 at 4000dpi 16-bit grayscale TIFF with no adjustments or corrections, re-sized then saved to JPEG. Please excuse the mess as this is the "junk pile" in the corner of the basement but it makes for a good torture test due the contrast. Also, please excuse the water marks ... I was being lazy and did not dry the film properly as it was only to be used for testing purposes and wanted to scan it as soon as possible.

Incidentally, adding 1g/L of Potassium Bromide makes this a good print developer as well.
Regarding Caffenol, the mix I prefer most is Caffenol-C-L by Reinhold (I do notice finer grain compared to other Caffenol recipes).

However, for whatever reason, the development with Tri-X was way too active (thick grey negatives, I posted about this on flickr) and I found that reducing the instant coffee to 1/4 the amount produced negatives that are still thick but usable. 

I definitely see the compensating effects but I find the dynamic range compression with Tri-X to be too much (it is better with medium speed films). It so happens that my scanner can resolve grain (this is what got me complaining about Tri-X and grain, the same negatives on an Epson V750 don't look nearly as bad despite technically having more resolution) and the same scene side-by-side with Caffenol-C-L vs PCB shows a dramatic difference with Tri-X. Plus-X looks good in Caffenol-C-L but side-by-side comparisons with PCB show significant differences in favor of PCB. 

Don't get me wrong, I'm not trying to knock Caffenol, I like it, it has it's place, and I will keep using it, but not as a
general purpose developer. I believe the strength of PCB is that it is in fact quite plain which means, similar to D-76 and XTOL, you get good results with pretty much any film and once you understand it, you can make it sing.
Regarding Tylenol, I am currently doing testing with a TCB (Tylenol / Vitamin-C / Borax) developer and the results are promising. I will let you know when I have more conclusive data to share.
Regarding your blog, I would love the opportunity to co-author and post my findings as my primary interest in film photography is around vitamin-c developers. I think having a vitamin-c developer centric blog is an excellent idea as much of this information is spread in different places on the Internet and having it all in one place would be extremely convenient (I wish I had this when starting out).
Regards, Michael


  1. Michael also sent 2 pictures these will be uploaded shortly.

    Thank you Michael!!

  2. I am a bit confused when the measurement for Borax is mentioned, is it 200gs in 1L? How do you measure 400ml of Borax?!