RA4 processing formulas

Photo Engineer · Oct 30, 2016

These are as authentic as I can get. It took me a while.

RA4 Developer
Water 700.00 mL
Triethanolamine 12.41 g
Blankophor REU ™ (Mobay Corp.) 2.30 g
Lithium polystyrene sulfonate (30%) 0.30g
N,N-Diethylhydroxylamine (85%) 5.40 g
Lithium sulfate 2.70 g
N-{2-[(4-amino-3-methylphenyl)
ethylamino]ethyl}methanosulfo-
namide sesquisulfate (CD-3) 5.00g
1-Hydroxyethyl-1,1-diphosphonic acid (60) 0.81g
Potassium carbonate, anhydrous 21.16 g
Potassium chloride 1.60 g
Potassium bromide 7.00 mg
Water to make 1.00 L

pH 26.7° C. adjusted to 10.04 +/- 0.05

Bleach-Fix

Water 700.00 mL
Solution of ammonium thiosulfate 127.40 g
(54.4%) + ammonium sulfite (4%)
Sodium metabisulfite 10.00 g
Acetic acid (glacial) 10.20 g
Solution of ammonium ferric
ethylenediaminetetraacetate (44%) +
ethylenediaminetetraacetic acid (3.5%) 110.40g
Water to make 1.00 L

pH 26.7 °C. adjusted to 5.5 +/- 0.1

Sorry about the formatting. I've gone through 3 iterations.

PE

dE fENDER · Oct 30, 2016

Thanks for your efforts.

How do you think, can the optical brightener be replaced without lowering quality with others? Such as tinopal?

Photo Engineer · Oct 30, 2016

That brightener was probably selected to give the minimum of yellowing with age and the minimum in bluing of blacks. I have seen Tinopal used, but only in a post process bath.

PE

mshchem · Oct 30, 2016

You mention Mobay Corp. This was a joint venture between Monsanto and Bayer based out of Pittsburgh . The big products were polyurethanes . Mobay got absorbed in to Bayer and Bayer spun off the polyurethane business several years back.
I was involved with appliance companies that used a lot of rigid closed cell PU insulation .
What the heck is Blankophor REU ? ?
Best Regards Mike

Gerald C Koch · Oct 30, 2016

APUGuser19 said:
Unbelievable. Look at some of those chemical names.

Welcome to organic chemistry. There are rules for naming chemicals and these names are logical and follow the rules. You should be able to look at the name and draw the structure. When you run into trouble is with pseudo chemical names like triethanolamine (prefered IUPAC name 2,2',2''-Nitrilotri(ethan-1-ol).

Mr Bill · Oct 30, 2016

mshchem said:
What the heck is Blankophor REU ? ?

Blankophor (or Phorwite) REU are "brighteners," often called stain-reducing agents. They absorb a certain range of UV light and emit a bluish color, helping to counteract any yellowing of the paper. Tinopal is also a brightener. I've often wondered about the effectiveness on paper, after washing, but perhaps small amounts are adsorbed? Just a guess, I've never seen anything obvious in the processed paper under a UV light.

As a note, if anyone in a commercial darkroom wants to see where developer has been spilled, you can take a UV light into a darkened room and see what glows. You'll see right away why no one who has developed a severe sensitivity to the developer can work in there anymore - traces on the countertops, doorknobs, etc., as well footprints. The brightener doesn't seem removable with normal cleaning methods so it hangs on there for a long time.

Rudeofus · Oct 31, 2016

Photo Engineer said:
RA4 Developer
[...]
Lithium sulfate 2.70 g

Can you confirm, that this is correct and shouldn't be Lithium Sulfite? There is no other source of Sulfite in your RA4 color developer formula ...

Photo Engineer · Oct 31, 2016

I can confirm that my source says Lithium Sulfate. I overlooked that and I suspect that it is Lithium Sulfite.

PE

dE fENDER · Oct 31, 2016

Kodak RA-4 MSDS contains exactly Lithium Sulfate, but always with Potassium Sulfite - http://hazard.com/msds/f2/cfk/cfkmy.html

Photo Engineer · Oct 31, 2016

Then that was omitted from the formula I got.

PE

DREW WILEY · Oct 31, 2016

Over my pay grade. Think I'll just stick with buying the RA/RT kits. Either that or Tide laundry soap.

Photo Engineer · Oct 31, 2016

I am working on an authentic copy of C41 as well. Any interest?

PE

Truzi · Oct 31, 2016

Photo Engineer said:
I am working on an authentic copy of C41 as well. Any interest?

PE

Not sure I'd be able to do anything with it, but I'd be interested to try at some time in the future.

dE fENDER · Nov 1, 2016

Photo Engineer said:
I am working on an authentic copy of C41 as well. Any interest?

PE

It's always interesting, but I'm afraid that many ingredients will be unavailable/too expensive for the most amateurs. In the other side - alternative recipes are working and the original lab chemistry is still available and relatively cheap.

twelvetone12 · Nov 1, 2016

Photo Engineer said:
I am working on an authentic copy of C41 as well. Any interest?

Yes please!

EdSawyer · Nov 1, 2016

Always interesting to know the actual formulas, yes! Especially for the future if it ever goes away commercially. Though I will confess to just buying the pre-made Kodak chemsitry (as long as it is available).

Stephen Frizza · Nov 1, 2016

Photo Engineer said:
I am working on an authentic copy of C41 as well. Any interest?

PE

Very Interested!

Photo Engineer · Nov 1, 2016

If you are a chemist and you know how to run crucial photographic tests regarding speed, grain, sharpness and color resolution, then you can do it!

I'll work on the C41.

PE

Photo Engineer · Nov 1, 2016

No battle plan survives the enemy and no formula is bullet proof. And, the formulas evolve as products change.

PE

darkroommike · Nov 2, 2016

Photo Engineer said:
I am working on an authentic copy of C41 as well. Any interest?

PE

Yes please.

FujiLove · Nov 2, 2016

APUGuser19 said:
Unbelievable. Look at some of those chemical names.

I'm now less inclined to get any on my hands!

Halford · Nov 2, 2016

FujiLove said:
I'm now less inclined to get any on my hands!

You should hear the names of the chemicals your hands are made of.

kb3lms · Nov 2, 2016

Yes, I'd like to see C-41.

Photo Engineer · Nov 2, 2016

You all must be aware that there are several "official" C41 formulas out there that I have my hands on. The product is evolving and so is the process.

PE

dE fENDER · Nov 3, 2016

Photo Engineer said:
You all must be aware that there are several "official" C41 formulas out there that I have my hands on. The product is evolving and so is the process.
PE

As far as I know, different formulae using in cases, when components become unavailable for some reasons, but sensitometric tests should be the same within tolerance region?

RA4 processing formulas

Privacy & Transparency

Privacy & Transparency