Homebrewed Colour Processes.

[Keith Tapscott.]

I found this link on the web. http://www.opie.net/orphy/photo/dr/wkft-e6.html

I wouldn`t have thought it would be worth bothering with over commercial film processing. My apologies if someone has already posted this or similar before.

 

[Photo Engineer]

Keith;

The first developer is wrong and the color developer is wrong. This will risk color shifts and crossover not to mention possible high Dmin values. I have seen this page here several times and have reminded people that the first developer uses HQ mono sulfonate, and the color developer contains Etylene Diamine.

PE

 

[Keith Tapscott.]

Keith;

The first developer is wrong and the color developer is wrong. This will risk color shifts and crossover not to mention possible high Dmin values. I have seen this page here several times and have reminded people that the first developer uses HQ mono sulfonate, and the color developer contains Etylene Diamine.

PE

Thanks for pointing that out. To save time trawling through the various threads and post, what is the proper formula for the 1st and colour developer?

 

[Ian Grant]

Ron, it may be wrong but they work. There have been various alternative formulae published over the years, I used one from the BJP for a while, and I know a large commercial lab in Birmingham made up all their own colour chemistry from similar formulae, ironically they were just a 30 second walk from Hogg's the chemical supplier mentioned. They bought from another supplier, Hoggs moved later to almost opposite).

When Hogg's stopped selling Photo-chemicals I bought the entire sock Rayco have gone as well.

Munns Brothers was the lab in question, they were a large lab taking C22/E4 then later C41/E6 from various retail outlets across the Midlands (UK), they had very able chemists and saved a fortune compounding their own chemistry, I don't know which formulae they used but I do know someone who would. The company closed the lab in the early 90's but only after diversifying becoming one of the largest operators of high street Minilabs in the UK, they are still canny, and last I heard were using Fuji Frontier machine with Tetenal chemistry, which is widely regarded as the best independent manufacturer.

Ian

 

[Photo Engineer]

Ian;

That formula may work with one film or brand of film but not another. I have seen one set of chemistry vary even within the same product across emulsion numbers. But, all of the products were ok in the standard release test.

Among other things, HQMS is milder and can reach the bottom layer to start development in a more uniform fashion overall and therefore it minimizes crossover and color shifts between slow and fast films. It was selected for this to work properly at 100 F.

I merely advise caution. Corrected formulas that were authentic were published about 15 years ago in a special edition of Darkroom Techniques. I have mislaid my copy or I would give that data. I turned in my actual formulary when I retired.

So, I would hesitate before I saw a direct comparison with this and authentic formulas.

PE

 

[darkosaric]

Did anyone drop an email to original author of text (Derek Watkins)? Is he active here on apug?

 

[Keith Tapscott.]

Did anyone drop an email to original author of text (Derek Watkins)? Is he active here on apug?

Is he? I was not aware of that. Perhaps you could send him a PM.

 

[Ian Grant]

I have to say Ron, I don't know where the Watkins formulae comes from, but I've known people who've used it with no problems regardless of film stock.

The formulae I've used have all been attributed to Ernst Gehret, who appears to have been an extremely able photo-chemist specialising on colour processing, he published a wide variety of alternative formulae from the 50's right through to E6, C41, RA-4, I don't know much about him but his formulae have always worked perfectly.

Ian

 

[Keith Tapscott.]

PE, I googled for Hydroquinone-monosulfonate, but I am still none the wiser of how it works compared to hydroquinone. I also came across chlorohydroquinone. I guess that they are all kind of related components, but have a very different working effect for developing. Perhaps you could explain the special properties of these components compared to regular hydroquinone.

 

[Photo Engineer]

Ian;

The article I refer to was probably by Pat Dignan who repudiated earlier formulations when he changed to the more nearly correct version. In the same magazine was a comparison of 5 different C-41 scratch mixes with the authentic Kodak formulation that showed similar problems.

In the group I worked in, we often ran 4 runs / day of film or paper in up to 12 developers per run. These were variations such as seen in the reference article. This resulted in literally thousands of test results comparing speed, curve shape, color reproduction, grain and sharpness. After years of that I must stand by what I said. Unless you show it to me with a fast and slow film from Kodak and Fuji side by side with the authentic E6 and we look at all factors, I believe that you will see random anomalies that may cost you some photos.

For all we know, the article itself is biased only showing one film and within that only the good slides. IDK. No accusations except the unknown, which to me as a photo engineer makes me wish to make you all aware of the situation.

Other than that, do what you wish.

PE

 

[Photo Engineer]

Keith;

HQMS-K salt is a very slow acting mild version of HQ itself. It is also very very stable. In this case, where you want all of the color layers to start to develop at about the same time and continue to do so, HQMS is virtually ideal when compared to HQ itself. This discovery led to a change in the E6 process very early on, to prevent overdevelopment of the yellow layer and/or underdevelopment of the cyan layer. In current products, balanced for HQMS the top and bottom layers of all E6 products from Kodak and Fuji expect this balancing act to be present in the first developer.

I might add that HQMS, to achieve this balancing act, is present in very high concentration. I think it is between 25 and 50 g/l.

ChloroHQ is very active and not in general use anywhere due to the extreme expense. I would have to look it up in my notes to be sure.

PE

 

[darkosaric]

Is he? I was not aware of that. Perhaps you could send him a PM.

I have send him a email - that there is interesting conversation and that he maybe can say thing or two

 

[Keith Tapscott.]

I have send him a email - that there is interesting conversation and that he maybe can say thing or two

Thanks, if he decides to participate in this thread, then his comments should be interesting to read.

 

[Keith Tapscott.]

Keith;

HQMS-K salt is a very slow acting mild version of HQ itself. It is also very very stable. In this case, where you want all of the color layers to start to develop at about the same time and continue to do so, HQMS is virtually ideal when compared to HQ itself. This discovery led to a change in the E6 process very early on, to prevent overdevelopment of the yellow layer and/or underdevelopment of the cyan layer. In current products, balanced for HQMS the top and bottom layers of all E6 products from Kodak and Fuji expect this balancing act to be present in the first developer.

I might add that HQMS, to achieve this balancing act, is present in very high concentration. I think it is between 25 and 50 g/l.

ChloroHQ is very active and not in general use anywhere due to the extreme expense. I would have to look it up in my notes to be sure.

PE

Sounds interesting, particularly the stability you mentioned. Is it more expensive to manufacture HQMS compared to HQ? If it requires much higher quantities in developers compared to HQ, then may be it is prohibitively expensive if used for B&W processes rather than just for colour processes.
I believe that chloroHQ was used in Paterson Acuprint developer, which might explain why it was discontinued.
Sorry to be off topic concerning colour developers, but I didn`t realise there were so many different HQ derivatives around.

 

[Photo Engineer]

Keith;

There is a rather longish thread on HQMS, and someone has posted the formula for making HQMS there. It is expensive as a solid, and the sythetic route gives very dilute HQMS so it is not a very viable procedure. If you can get and handle 30% peroxide, this might help. The synthesis posted uses 3% IIRC.

The 30% variety can be very dangerous to work with.

PE

 

[Alan Johnson]

Ascorbate ion is probably smaller than hydroquinone,might diffuse more rapidly,would that be worth an experiment with ascorbate instead of HQMS?

 

[Photo Engineer]

Alan;

AFAIK, ascorbate did not work with E-6, but then I may have missed the report if it was tried and reported on. It might be that a stable liquid kit could not be made. IDK. I would be interested in the result if you try it.

PE

 

[Alan Johnson]

PE,
You mention also that the color developer may contain ethylene diamine.Is it known how much?Is it essential,the Fuji Formula does not have any?
www.apug.org/forums/forum40/45857-e-6-color-reversal-development-fuji-recipes.html

 

[mts]

E6 color developer requires ethylene diamine, at 4 ml/liter for the free-base. You can also use ED sulfate with adjustment for molecular weight, but it is needed for proper penetration of the lowest emullsion layers.

 

[Photo Engineer]

Ethylene Diamine is a mild silver halide solvent that helps attain good dmax with good dmin at the same time.

I missed what MTS said. He is correct as well. There is a mild penetrating effect related to ED.

PE

 

[Photo Engineer]

Alan;

The formulas you cite here: (there was a url link here which no longer exists) are the most nearly correct E6 formulas I have seen published.

Note that DTOD seems to replace ED in the color developer. This is a rather recent change if correct. I would not have done that.

PE

 

[darkosaric]

Thanks, if he decides to participate in this thread, then his comments should be interesting to read.

Well, I got mailer daemon:

"Sorry, we were unable to deliver your message to the following address..."



regards,

 

[Keith Tapscott.]

Well, I got mailer daemon:

"Sorry, we were unable to deliver your message to the following address..."



regards,

I haven`t seen any magazine articles written by Derek Watkins for a long while now.
I think his last publication was a book about Bromoils. It would have been interesting to read his comments on this thread if he participated. The formula in the link obviously satisfied him, but didn`t get past PE`s high quality standards.

 

[Alan Johnson]

It's hard to find ethylene diamine for sale.Presumeably it would be OK to use EDTA and add some extra Sodium Hydroxide in Watkins' formula?

 

[Photo Engineer]

It's hard to find ethylene diamine for sale.Presumeably it would be OK to use EDTA and add some extra Sodium Hydroxide in Watkins' formula?

That will not work at all. EDTA is totally different in action.

PE