How do you test BLIX is working?

I have not given the name of the current biocide. I tried to order some and I need a licence for anything but very dilute mixtures. This is what Kodak and others appear to use. It is quite safe at the dilution used. It should be used, or use Formalin as described before. One or the other, your choice.

Now, as far as the gunk is concerned, all Stabilizers and Final Rinse solutions contain some sort of surfactant. Kodak uses Photo Flo. It can gunk up many pieces of equipment if not used properly. I have used it in reels for years and find that a simple rinse with warm water will clean away the gunk.

PE

lantau said:

ecn2 dyes are stable. The Kodak process does not use Formaldehyde anywhere.

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I'm not sure. The fact that there seems to be no formaldehyde-like compound in the final rinse is not proof that the dyes are stable. They may be stable enough for the intended application in the movie business. Since ecn-2 dyes are likely similar to E6 dyes (they use the same developing compound after all), it's possible that long-term stability requires a similar stabilizer as E6 films.

Mike Chalmers said:

I noticed that Process Supplies are selling it about £200, so it's really not much of a saving - but I'd be interested to hear about 20l for £100 if it's a variety you'd recommend.

My plan is to go through my Tetenal (arrives tomorrow) over the next month then try out the Fuji Press Kit.

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My latest tetanal 2.5l kit instead of having separate bleach and fix have gone down the 'blix' route. The mixing recommendations show they should be mixed together with water to make up the quantity, but as the bleach and fix concentrates come in separate bottles I wonder if it is possible to mix the beach and fixer separately and use it that way. Any suggestions/comments before I start..

Mike Chalmers said:

Hello, first post but have dipped in and out recently.

I've been processing my own C41 for a few months and thoroughly enjoying it.

I've had an issue the past few rolls, which I believe is down to my Blix, as I found sediment in it. I've effectively filtered it all out, using double-bagged coffee filters, but I would like to know any methods for testing the efficacy of the blix I have.

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I have ordered new chemicals, but I would like to get as much knowledge as I can, so I can troubleshoot later issues, so I'm happy (well, prepared) to lose a roll if needs must.

I use the Tetenal Colourtec kit in a Jobo CPE2.


Thanks

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There should be instructions in the kit that tells you how many films you can process with a given quantity of chemicals so really there is no need to test. That is the way I work. I also always give more time than the process suggests, so for the 1st film instead of 6mins I always give a full 6 mins 15 secs and each subsequent film with the same dilution I give an extra 15 seconds until I reach the maximum recommended capacity for that quantity.

In another post you mention Process Supplies, have a look at Morco.co.uk, they are almost certainly cheaper for both chemicals and film. They are very obliging and will get in what you need if they don't already have it in stock.

koraks said:

I'm not sure. The fact that there seems to be no formaldehyde-like compound in the final rinse is not proof that the dyes are stable.

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Hollywood was a driving force behind getting movie film stable. Note, that current Vision 3 movie film is based on very similar technology as Kodak's latest incarnation of Portra film, therefore I would expect it to be on the same technological level.

PS: it may be time to stop raging about Tetenal's BLIX. Many people who warned against BLIX will also confirm that Tetenal's BLIX is very good. Tetenal is the outfit that still makes many of Kodak's photo chemistry products, we might as well assume that they are neither careless nor silly.

Rudeofus said:

Note, that current Vision 3 movie film is based on very similar technology as Kodak's latest incarnation of Portra film

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Really? They're chemically completely different emulsions with fundamentally different dye configurations. I've seen people say that they see a visual similarity between portra and vision3 (I don't agree entirely, but I can see the point), but this says nothing about technical similarities. When it comes to those, I have not been able to find specific information on the similarities between Portra and Vision 3 and due to the evidently different dyes, it would be risky to assume that they perform identically in the specific respect of dye stability. Note that Kodak does offer information for Vision3 recording film on optimal long-term (>6 months) storage conditions, but not on dye stability. Kodak does assert that its digital intermediate film has excellent dye stability, but it is not clear if this extends to the recording film as well.

While it's perfectly possible that the vision 3 dyes are long-term stable without a stabilizer being used in the process, it surely doesn't hurt to use a stabilizer.

koraks said:

Really? They're chemically completely different emulsions with fundamentally different dye configurations. I've seen people say that they see a visual similarity between portra and vision3 (I don't agree entirely, but I can see the point), but this says nothing about technical similarities. When it comes to those, I have not been able to find specific information on the similarities between Portra and Vision 3 and due to the evidently different dyes, it would be risky to assume that they perform identically in the specific respect of dye stability. Note that Kodak does offer information for Vision3 recording film on optimal long-term (>6 months) storage conditions, but not on dye stability. Kodak does assert that its digital intermediate film has excellent dye stability, but it is not clear if this extends to the recording film as well.

While it's perfectly possible that the vision 3 dyes are long-term stable without a stabilizer being used in the process, it surely doesn't hurt to use a stabilizer.

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Archiving the camera negatives seems to have been standard procedure. I have the Star Trek TNG TV series on Bluray in FullHD and they were produced from those camera negatives a few years ago. They used 35mm film, btw.

In their brochure for Vision positive print film they say something along the line that print film was never intended for long term storage, that is the role of the negatives. Though they do appreciate that many collections have the prints only and I guess the latest print film will do fine.

From what I read here it isn't so much that the dyes as such are unstable but unused couplers can react with the formed dyes and render them useless. Formaldehyde will react with those excess couplers instead and everything is fine.

There is no reason why Kodak wouldn't have solved this problem in the latest cinefilms like they did with their C41 films. The fact that it is using CD3 doesn't necessarily mean it is a close relative to E6. And RA4 is using CD3 without Formaldehyde and excellent stability.

lantau said:

But with the OP doing 20-80 rolls a week(?) that's not healthy.

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Haha, not quite per week. I do anywhere between 20 (a slow month) and 80 (busier) per month. I shoot jobs in addition to personal work and frequently used a nearby pro lab but I love working in the darkroom myself. It is scary when the shots are important (my shots are important to me, but when a client is expecting results, it's another pressure altogether). Mistakes and problems are inevitable but I want to learn as much as I can and recognise and prevent issues quickly.

@lantau while your reasoning makes perfect sense, fact of the matter is that we just don't know. Kodak offers their digital intermediate film and specifically states that it has excellent dye stability (>100 years under optimal storage conditions). No such claim is attached to the Vision 3 recording/camera film, while if the dye stability were of similar performance, you'd expect they would tout such a benefit, which they don't. Without in-depth verifiable knowledge of the material itself, we can only second-guess. Based on my own guessing, I have started using a formalin stabilizer - if anything, it'll help a bit in preventing fungus. Maybe it even helps with dye stability, but who knows for sure? Maybe it's not a necessity, but even then, it doesn't hurt - as long as some care is taken into consideration in handling the stuff.

Mike Chalmers said:

Haha, not quite per week. I do anywhere between 20 (a slow month) and 80 (busier) per month. I shoot jobs in addition to personal work and frequently used a nearby pro lab but I love working in the darkroom myself. It is scary when the shots are important (my shots are important to me, but when a client is expecting results, it's another pressure altogether). Mistakes and problems are inevitable but I want to learn as much as I can and recognise and prevent issues quickly.

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Oh, I see. In any case. Photo Engineer has made it clear that C41 final rinse has a suitable biocide to preserve film. I'd recommend that over frequent use of Formaldehyde. The problem with it seems to be chronic exposure possibly leading to cancer in the upper respiratory tract, if my memory is correct. One of my chemistry teachers and, later, one organic chemistry prof were rather angry in their rebuttal of cancer claims towards formaldehyde and benzene. They were like wet plates in a digital age

Photo Engineer said:

I have not given the name of the current biocide. I tried to order some and I need a licence for anything but very dilute mixtures. This is what Kodak and others appear to use. It is quite safe at the dilution used. It should be used, or use Formalin as described before. One or the other, your choice.

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Thanks for unequivocally confirming that. I remember someone having asked Ilford about their b/w wetting agent and the answer was that their biocide will only protect the concentrate. I can confirm that the working solution of Adox Adoflo, which also has biocide, will have that rotten water smell after two or three weeks in the bottle.

It is good to know that the C41 final rinse is a different beast.

koraks said:

@lantau while your reasoning makes perfect sense, fact of the matter is that we just don't know. Kodak offers their digital intermediate film and specifically states that it has excellent dye stability (>100 years under optimal storage conditions). No such claim is attached to the Vision 3 recording/camera film, while if the dye stability were of similar performance, you'd expect they would tout such a benefit, which they don't. Without in-depth verifiable knowledge of the material itself, we can only second-guess. Based on my own guessing, I have started using a formalin stabilizer - if anything, it'll help a bit in preventing fungus. Maybe it even helps with dye stability, but who knows for sure? Maybe it's not a necessity, but even then, it doesn't hurt - as long as some care is taken into consideration in handling the stuff.

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Yes, I don't see that 100 year claim either, but at least in the July 2015 datasheet for V3 50D (5203) they mention 'proven archival stability'. I didn't look up the other V3 films. Storage conditions for processed film for periods of more than six months is 2°C at RH 20-30%, however. Pretty cold and dry.

I have photoflo with formaldehyde anyway, to make sure the bugs won't bite. As you say, we're on the safe side in any case.

Formalin and other biocides do not help with dye stability nowdays so much as they do with film stability. They prevent bugs of all sorts from eating the gelatin.

Formalin and benzene are indeed reported to cause cancer in animals, but there is still some doubt about it in people. There is no doubt that they cause respiratory problems in all animals and humans if subjected to long exposures or concentrated amounts. I've been rather "saturated" with both chemicals at one time or another as have many of my associates and friends. We are still going strong in our 80s and 90s. Our cancer statistics are rather normal for this age group.

Kodak does stabilize many films and papers and had an active image stability program of which I was a part for a few years. Current MP films are going to be stored under optimum conditions, and exposed to light infrequently, and therefor are stabilized for those keeping conditions that the film is expected to see. Print films have little stability as any given print is not expected to last long due to handling and exposure to light during use (shipping and projection).

PE