RA4 processing formulas

fdonadio

Member
Joined
Jan 15, 2015
Messages
2,116
Location
Berlin, DE
Format
Multi Format
I got a quote on most of the chemicals (from original post) from Sigma-Aldrich.

Some are very expensive. Sigma-Aldrich don't carry 3 or 4 of them and these are very hard to find elsewhere — Blankophor REU, for example.

And, to wrap it up nicely, Triethanolamine is a controlled substance in Brazil. Seems to be explosive or, at least, highly combustible. I still didn't bother to read the MSDS.

So, I'm sticking with off-the-shelf RA-4 for now.

Still, my kudos go to Photo Engineer for the great research work!


Cheers,
Flavio
 
OP
OP

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
There is quite a discussion here on APUG a few years ago suggesting that we heat triethanol amine on the stove or in a microwave due to its low flammability. In fact, several APUG members tested it on the stove and in microwave ovens to prove/disprove this. Thankfully all are alive, but I dont recommend it.

PE
 

Michael Guzzi

Member
Joined
Jan 15, 2016
Messages
178
Location
Caxias do Sul/RS, Brazil
Format
35mm
I can't believe the morons in charge of this big, bad joke.

Completely random restrictions on stuff that is pretty harmless. Others not so much, but it's not like you can craft an A-bomb with TEA... And import restrictions aren't necessarily the same restrictions that apply for the domestic market. Go figure...

/rant
 

darkroommike

Subscriber
Joined
Mar 22, 2007
Messages
1,728
Location
Iowa
Format
Multi Format
I'm fortunate enough to have a magnetic stirrer hotplate for heating chemicals and smart enough to read an MSDS before "playing" with anything like TEA, glycols, etc. And I have a big ABC fire extinguisher standing by, that I usually keep in my woodshop but move to the darkroom at times.
 

fdonadio

Member
Joined
Jan 15, 2015
Messages
2,116
Location
Berlin, DE
Format
Multi Format
Michael Guzzi said:
Completely random restrictions on stuff that is pretty harmless.
Click to expand...

I see where you're coming from and I feel pretty much the same. In this case, the substance is controlled by the guys who wear green potties on their heads. Maybe they know how to make a WMD with 100 grams of Triethanolamine.

But one thing I am sure: this is all for the greater good! Even though my father could buy 20 liters of muriatic acid, over the counter, 50 years ago... and didn't have to fill a single form for that!

Crazy world our old men lived in, eh?

Cheers,
Flavio
 

Larry the sailor

Member
Joined
Feb 3, 2016
Messages
333
Location
NE Oklahoma
Format
Multi Format
My grandfather, born in 1903, was at one time able to go to his local farm Co-Op and buy dynamite and caps to relocate stubborn stumps and rocks. As he lived to the ripe old age of 96 he apparently managed to do so with out prematurely relocating himself to the hereafter.
 

Gerald C Koch

Member
Joined
Jul 12, 2010
Messages
8,131
Location
Southern USA
Format
Multi Format

nworth

Member
Joined
Aug 27, 2005
Messages
2,228
Location
Los Alamos,
Format
Multi Format
Some years ago, Steven Keirstead presented several experimental formulas here for RA-4 processes. They were based on a formula very similar to what is listed above. Here is the basic one:

RA4-Compatible Developer Formula (6/2005)
by Steven Keirstead

This new formula is closer to an old Kodak RA4 developer formulation, but with a bit extra developing agent, which makes it work better in my Fujimoto CP-31 roller transport processor at 35-36?C. pH should be 10.4-10.5 or so, adjust if needed. This recipe seems to necessitate high magenta and yellow filtration values, but produces nice looking prints with excellent color and contrast.

Conc. Amt.
Water, Deionized or Distilled 700 mL 1.2 L
Triethanolamine 12 g 20 mL
Lithium polystyrene sulfonate (30%) 300 mg 1.65 mL
N,N'-diethylhydroxylamine (85%) 5.4 g 13.0 mL
Lithium sulfate 2.7 g 5 g
Color Developer Agent CD-3 5.75g 10.6 g
Etidronic Acid (60%) 1.2 g 2.55mL
Potassium carbonate 21.2 g 39 g
Potassium bicarbonate 2.7 g 5.2 g
Lithium chloride (20% Soln) 910 mg 8.4 mL
Potassium bromide (7g/L Soln) 7 mg 1.85 mL
Water, Deionized or Distilled to 1 L 1 L

Ref: APUG

(I hope the formatting worked!)

My guess is that the lithium sulfate is to control emulsion swelling at the 100F processing temperature. Because of the critical diffusion behavior during processing, the amount may be important. I also suspect that the use of lithium salts may be important because of the size of the lithium ion, but the exact chemistry is beyond me. Note that there is no sulfite in this formula. Perhaps the Etidronic acid acts as a preservative. Keirstead says this formula was based on an old Kodak formula, perhaps the same one PE has. Kodak used to publish its color formulae for materials that could be processed by labs and others. They were not widely available, but they were available. Maybe someone has some old references.
 

Rudeofus

Member
Joined
Aug 13, 2009
Messages
5,081
Location
EU
Format
Medium Format
The amount of Sulfate ion is waaay too low to prevent any amount of swell. Lithium is required to prevent the Etidronic Acid from freaking out. Etidronic Acid (1-Hydroxyethyl-1,1-diphosphonic acid in PE's formula, also sold as Dequest 2010) is not an oxygen scavenger, but a very powerful sequestering agent for trace metal impurities like iron and copper. It can't cope well with regular water hardness and will eventually create a whitish precipitate unless there is a source of lithium or magnesium ions in the mix. The polystyrene sulfonate is there to cope with regular water hardness.

A brief note on the lack of Sulfite: yes, it was quite surprising to me at first, but now that I think of it it makes sense. Sulfite will scavenge oxidized color developer, and therefore compete with color couplers in RA-4 material. This means that silver ions will be reduced to silver just to convert CD-3 into CD-3 Sulfonate, and RA-4 designers didn't want to waste a trace of silver in this process. Note, that the CD-3 is not completely unprotected from aerial oxidation, there is quite a lot of this hydroxylamine derivate in this formula.

This is what surprises me: RA-4 was one of the most widely used color process with ridiculously high volumes, much more than all other color processes taken together. There must have been tremendous economic incentive to optimize the heck out of every component in RA-4 developer, yet they use fairly expensive ingredients to work around limitations of others. For some reason or another, I find it difficult to believe that these formulas represent the most recent iteration of this product.
 
OP
OP

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
Yet, it may not be possible to make an extensive change and maintain compatibility with your own and other companies products. That is why many changes have not or cannot be introduced into the trade.

OTOH, I can note that Sulfite ion can be used to reduce the contrast of RA4 papers, but with too much, the Dmax goes down.

PE
 

Rudeofus

Member
Joined
Aug 13, 2009
Messages
5,081
Location
EU
Format
Medium Format
Photo Engineer said:
Yet, it may not be possible to make an extensive change and maintain compatibility with your own and other companies products. That is why many changes have not or cannot be introduced into the trade.
Click to expand...
The sheer volume of RA-4 processing should have made research on improving RA-4 CD economy much more likely than research on other color processes. Let's not forget, that C-41 was updated this century (bleach III, no need for Formalin, ...), so why wouldn't Kodak try to get rid of lithium salts in RA-4 CD?

PS: Sigma Aldrich used to carry photo grade Lithium Sulfate, but that product has been removed from its offerings. I would take this as a further indicator, that Lithium is no longer used in commercial photographic products.
 
OP
OP

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
Rudi, the color developer is THE critical step. That is why it is so hard to replace.

I once selected a group of production color papers and ran them as checks with 12 experimental developers, a 6 x 13 factorial, which generated a LOT of data. The production coatings in production developer were all within tolerance as would be expected, but the results in the 12 other developers were all over the map with generally, one of them being within specs. Among the variables were NaBr, NaCl, Benzyl Alcohol (back in the day), Carbonate vs Kodalk, and the results were astonishing to me. But, not to the old hands. They told me how hard it was to change developer formula on the fly. BTW, one experimental coating was the same in a majority of the above, but only at a different development time.

PE
 

Rudeofus

Member
Joined
Aug 13, 2009
Messages
5,081
Location
EU
Format
Medium Format
Tetenal's RA-4 soups, as far as I can tell from their MSDS, are formulated quite differently. While an MSDS doesn't have to list everything, it does list compounds which are not in the two recipes posted in this thread, most notably DTPA (the same sequestering agent that Xtol uses). Therefore I conclude, that it's possible to reformulate RA-4 CD with more modern sequestering agents, and that some commercial entities have already done this.
 
OP
OP

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
Rudi, some coatings might be good but out of spec for some critical uses. How would you like highlights in a white wedding dress go green?

PE
 

nworth

Member
Joined
Aug 27, 2005
Messages
2,228
Location
Los Alamos,
Format
Multi Format
Keirstead was experimenting so that he could get results on Fuji papers that matched the Kodak stock. Apparently at that time Fuji papers had poor blacks when processed in Kodak chemicals. So, at least from time to time, there have been differences.
 

Rudeofus

Member
Joined
Aug 13, 2009
Messages
5,081
Location
EU
Format
Medium Format
Photo Engineer said:
Rudi, some coatings might be good but out of spec for some critical uses. How would you like highlights in a white wedding dress go green?
Click to expand...
Tetenal is not Rudi's garage shop tinkerers inc., they are AFAIK the outfit which manufactures Kodak photochemistry today. nworth's quote "at that time Fuji papers had poor blacks when processed in Kodak chemicals" tells me, that all was not fine and dandy when Kodak was still king, emperor, and sole judge in the supreme court of photography.

Here are paraphrases of some more statements I have read here, originally authored by seasoned lab workers and/or experienced photographers here on APUG:
The original formula is of little consequence, because each lab would dial in their process liquids with test strips anyway - and they had to. Process chem manufacturers would provide instructions how to adjust process liquids if results were off.
Click to expand...


I had to set my Jobo CPE2 to 39.5°C in order to maintain 38.0°C inside the tank ... but I wanted to keep it set to 38.0°C, so I changed my CD formula to give good results at ....
Click to expand...

pH meter reading may change if the liquid is a reducer/oxidizer, therefore pH measured with a standard pH meter and KCl filled glass electrodes will not be accurate for developers and bleaches.
Click to expand...

So here I sit, a lazy slob with a stash of somewhat aged RA-4 paper, and certainly no access to the exact chemistry batches that Kodak used to design and manufacture their process liquid concentrates. All that effort invested in sourcing photo grade Lithium Sulfate would be better directed at properly dialing in a formula consisting of comparatively easily available compounds for the few paper types I will likely deal with.

BTW I use an RA-4 formula that I found somewhere in a book, mixed with chems from sources that likely didn't exist when that book was originally written, and I reuse my RA-4 CD until its originally light golden color has turned into cinnabar red. My RA-4 process run for a night starts with 500ml, and typically ends after some hours when there is not enough CD left to process larger sheets (I don't prewet, and CD gets lost from carryover), which require around 200ml.

Since my C-41 negs are all over the place (film brand, color of ambient light, exposure, home brew development), I have to adjust filtration for each negative individually. Once that is dialed in, I most definitely don't see green wedding dresses or blacks with obnoxious discoloration. A densitometer may see some defects, but I process my pics for eyes, not densitometers.

Developed C-41 films contain bar codes on their rebate, which allegedly tells scanners how to adjust colors. If scanners have to adjust colors based on film type, I am not at all surprised that I have to adjust filtration between film stocks. The Durst 707 color enlarger I have access to has a color sensor which provides hints how to set filtration. All this tells me that my needing to adjust filtration for each negs is absolutely standard operating procedure, and not proof of a completely messed up work flow.
 

alanrockwood

Member
Joined
Oct 11, 2006
Messages
2,185
Format
Multi Format
PE, is there a particular order of mixing? Also, can you comment on the stability of the raw materials and mixed solutions?


 
OP
OP

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
Alan, the only thing critical is putting in the Hydroxyl Amine before the CD. Same thing for Sulfite if present.

PE
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…