Home-processing C41?

[discpad]

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Terence,

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Shooting film is one thing; making prints is quite another... Unless, of course you plan on shooting color transparency film and projecting it!

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By the way, Ron Mowrey also has a patent on blix, so he knoweth what he speaketh about when he admonishes you for using it as the tail end of C41 or E6 film.

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Again, the issue for C41 chemistry future availability will be the developer, not the bleach and fix, which can easily be formulated from scratch, as can many B&W developers.

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And, this is the worst case scenario, i.e. Kodak and Fuji both completely shut down.

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My advice, if you're REALLY serious about chemical availability 20-30 years down the road, is to start TODAY with the C41B process with REAL Kodak &/or Fuji Hunt chemistry, and learn the process. Then, using test rolls of cheap film, start by making your own fixer using <a href = "http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=009ZDV" target = "_blank"><u>Ron's recipe</u></a>:

 

 

<blockquote>

<p>4. I gave the formula for a super fix to Bud Wilson at the formulary expecting nothing in return. It is ammonium based and near neutral in pH. I include it here for reference. It is not free to use for profit by anyone but Bud if he desires. I wish to get nothing for this formula. I disclaim any liability that might arise from its use.

 

<li>Ammonium Hypo solution 150 - 200 ml/l

 

<li>Ammonium Sulfite 10 g/l

 

<li>Ammonium Thiocyanate 10 - 100 g/l

 

<li>pH 6.5 - 6.7 at 20 deg C with 28% acetic acid. </li></p>

 

<p>If you wish extra power add:

 

<li>Thiourea 10 - 100 g/l

 

<li>KI 1 g/l </li>

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In any event, do not use KI with papers, as it slows fixing rate, but accelerates fixing rate of films. Use with caution with color films, as it can cause or accentuate any cyan leuco dye problems. Don't go overboard and use the max of all of those ingredients. That is a possible range for any one of them at a time. If you max out all of them, you can actually slow down fixing rather than increase it. I used to test variations with strips of film snipped off a roll for this purpose.

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It is a very rapid fix for films and papers (minus the KI for papers of course) and can be made even faster by the group of proprietary materials patented by EK which I will not get into here of course. These are of particular use in color fixes.

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Make sure you wash film/paper, equipment and hands well, and take precautions for toxic materials used. This fix like most all fixes is a powerful fogging agent for film if small amounts get into a developer. Thiourea and all thiocyanates increase the hazard of photographic solutions.

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This formula is loosely based on USP 3,706,561 granted to Rowland Mowrey, Keith Stephen, and Eugene Wolfarth.

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<b>Cheers! <br>

Dan Schwartz <br>

Cherry Hill, NJ <br>

Click <a href = "http://users.snip.net/~joe/default.htm" target = "_blank">

<u>here</u></a> to visit my home page!

<br></b> [Note: <i>All links open a new browser window</i>] <br>

 

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[terence_mahoney]

Yep, sounds like I'll be sticking with B/W. I'm no mad scientist, I just want to tear open and envelope, mix it up in water and go to it.

[jerry thirsty]

I don't know if anyone is still following this thread, but I thought I would add on what I've got.

 

In addition to the two rolls (of 120) I ran through the three year old kit I mentioned earlier, I had another four rolls of unimportant film, so I decided to give those a shot as well. When I got the bottles of chemicals out, I found that the stabilizer had finally dissolved into solution since my previous attempt. There was no additional sulfur precipitate visible in the blix. I ran two rolls through, again with the 9 minutes in the blix. This time I didn't do a wetting agent rinse after the stabilizer; the water didn't run off evenly so I got some water marks and in a couple of places the film actually crinkled because it didn't dry at the same speed where the water drops were compared to the areas around them. Finally I ran my last two rolls through. I tried extending the blix time to 12 minutes to see if it would have any effect; I don't see any, the film base still looks a little more coppery than normal. Also, I did use an LFN rinse on this batch and they dried normally.

 

I just got another Press Kit in the mail today, and I see they've made some changes compared to the old kit I had. The old kit had a single packet of blix concentrate, the new kit has the blix split up into parts A and B. I would guess that they did this precisely to reduce the degradation over time, so maybe the kit has a better shelf-life now? Also, the instructions have been condensed. Some of the tips that are in the old instructions are missing, but on the other hand they have added information on push-processing and chromogenic B&W. Finally, the capacity they state now is 8 rolls of 120 (or equivalent). They have added a vague paragraph about how, if you're willing to take the risk, it is possible to process 50% or more than is stated, but they no longer provide the chart of corresponding time increases that was in the old instructions. I think I will hang onto the old set of instructions for additional reference.

[craig_shearman1]

Fixer: Still will be used for x-ray film until the cows come home. ----My wife's a doctor at Johns Hopkins. They've already gone digital for x-rays there, though they still use both. My dentist is all-digital for x-ray.

[discpad]

Craig,

 

I don't think they'll stop making x-ray film for a long, long time. And, even if they do, ammonium and sodium thiosulfate -- The active ingredient in fixer -- has other uses in industry besides in the photographic industry; and that is my point.

 

The only chemicals used in C41, E6 and RA4 that don't have other uses are the color dyes used in the color developers.

[discpad]

Jerry,

 

Color film developing is totally unlike B&W film: It's a very precise chemical process, with tightly maintained time, temperature, specific gravity and (especially) pH values. You are basically developing three separate pieces of film, and you have to match the D(min) & D(max) points as well as the 3 separate contrast curves.

 

Even if you play with the so-called first "B&W step" in the E6 process, you can still get color shifts if you don't nail it.

 

When you use half-assed chemicals and processes, such as "blix" and 3-step E6, you're looking for trouble.

 

Also, you should *really* pay attention to Ron Mowrey's admonishment on using the strong blix required for E6 & C41 -- He has patents on the weaker blix (which does work) for the RA4 process.

 

Cheers! Dan