Tetenal C-41 1L rolls amount, quality, etc

[ciaran_mcmenemy]

<p>I apologise if this has been asked before, but I can't find the information. I will number so you can direct your answers.<br>

1) I have 1L of tetenal mixed and stored in black collapsible bottles, and it's stored at room temperature. What's the shelf life? I'm not expecting long, but I expect that the blix would last a while (my bw fixer mix has outlived a bottle of developer, and has been in a bottle since April!!) and that the stabiliser would last a while too since it's simply formaldehyde gas in water, I think (is this the most poisonous of them all?). <br>

2) So far I've done 12 rolls. After rolls 13-14 there is no more information given. How come the blix time increases much more than the colour developer time?<br>

3) What's the most rolls you would get out of this? what happens when you keep going, does the film look more and more dull or something?<br>

4) How do I dispose of the chems? I suppose the developer and stabiliser can be poured down the sink, but the blix contains silver so I'm not sure what I would do with that one.<br>

Thanks for your time!</p>

[bernard_lazareff]

<p>http://rangefinderforum.com/forums/showthread.php?t=63614<br>

http://www.rangefinderforum.com/forums/showthread.php?t=97798</p>

 

[Bill C]

The definitive document is Kodak's Z131 publication - Kodak invented the C-41 process. It was really designed as a

"replenished" process, running in a stable condition. Extended use with increasing development time is really something

of a "kludge," but many people seem satisfied with this method.

 

I've never used C-41 "blix," but it seems to me to be like trying to paddle upstream. I'd guess that the extended times are

largely an issue with the fix portion, mainly a build-up of byproducts that "poison" the fixing process. (If you ran a regular

bleach, it would not need increasing times.)

 

For disposal, you really need to look at local effluent regulations, but most amateurs probably just dump down a drain

connected to a municipal sewer. ( Industry is generally regulated, with most finishers, at least in the US, operating under

conditions of a special sewering permit with stringent silver limits.)

 

As a note, I probably have about as much C-41 experience as anyone, but it's been with in-spec processes, so I'm mostly

guessing about operations outside of this.

[peterbcarter]

<p>What Bill said and ....</p>

<p>If you do not use the chemicals at all, the Dev will die after 2 months. Oxygen and PH are the evil doers. I use a divided C-41 developer and I can sometimes get as much as a year just because of the difference in PH (CD4 is stored with an acidic mixture). When overused, there are colour shifts as the R G and B layers start developing at different rates, if at all.</p>

<p>The blix will last for about 4-5 months unused and will die with the stated limit of rolls with use for the reasons Bill stated. If over used, all the silver does not get removed and your film will turn blue over time.</p>

 

[ciaran_mcmenemy]

<p>thanks for the replies! I didn't find all the answers on those two links up there, so you're most helpful.<br /> So Tetenal isn't actually that good? I thought it would effectively the same as what a lab uses. Except for the bleach and fix: I was interested in doing them separately (I thought about trying a slight 'bleach bypass') but to be fair combining them does prevent the risk of picking up the wrong bottle at a stage in processing.<br /> Yup, oxygen is a real killer!<br /> With regards to dumping blix, is it safe to put steel wool in it first? (Something like that is supposed to combine with the silver particles). <br /> -Peter: So you develop each colour separately. That's interesting! How long does it take for each? You could tone them with that method, too, although it would be more sensible to do it through scanning .. <br /> Thanks for explaining what actually happens when you overuse it. Anyone have any photo examples? Once I am done with my latent colour films (still a few out of the 12-16 or so I stored in the fridge) I will run a test: develop for a lot longer, and develop at the wrong temperature. I'd like to see what happens</p>

[peterbcarter]

<p>No I don't develop the colours separately. :) C41 film has at least 3 layers, One for the Green, Red and Blue. I think FUJI introduced a Yellow. That's where developing to standards get's important. It is easy to have the layers develop at different rates and shift the colour. One of the reasons why the temp is increased during processing. It's to ensure the development of all layers consistently.</p>

<p>This is an example of colour layers development problem. On the table, the rear right leg should be black but shows up as blue. This was EKTAR and is particularly sensitive to this.</p>

<p>It was developed at room temperature. Me breaking the rules again... The image is otherwise ok.</p>

<p><img src="https://c2.staticflickr.com/6/5047/5355632893_7dd7d6bba4_z_d.jpg" alt="" /></p>

[john_shriver]

<p>Tetenal kits were designed as a "press kit." They were to be used by press photographers in the field, who had to get a color negative developed "adequately well" on short deadline. Long life of the mixed chemicals wasn't a goal. Simplicity if mixing and processing was a goal, which is why they use a blix.<br>

C-41 blix is a "no win" game. Self-destructs, and hard to get ideal bleaching or fixing.<br>

The real "professional" C-41 processing chemicals are from Kodak (Flexicolor) and Fuji-Hunt. Nobody else has a license for all the patents and trade secrets needed to make the "real thing." (Kodak and Fuji have it tied up in patents, and cross-license.) Problem is, neither one really makes any products directly suited for home use, as there isn't enough market for that. So the smallest kits make a LOT of chemistry.</p>

[ciaran_mcmenemy]

<p>So what chemicals do you use? <br />If there is a little shifting / colour bias would the scanner ignore it or would it treat it as if you'd been using a filter? <br />If the layers are sensitive to RGB or RBY but show up as cyan, magenta and yellow, then what about slide film? Are those layers sensitive to CMY? I don't understand how they make it different; since you can make a negative out of it as well.<br>

Hah, blue table leg, does that mean the blue in the basket should also be black?<br>

where you developing by some guidelines or just experimenting? I bet you've made some good findings.<br>

---<br>

I was wondering why the called it a 'press' kit. funny, since I'd expect almost all publications to use digital these days.. perhaps National Geographic uses film photos? </p>

[peterbcarter]

<p>The blue on the table leg is supposed to be a darkly exposed area and EKTAR has a reputation for failing in darker areas. In this case it was pronounced by me developing at room temperature. Cure: I don't buy EKTAR any more. :)</p>

<p>You've asked a pretty technical question. I will give you a short easy answer to it.</p>

<p>C-41 film is created with at least 3 layers. Each layer will have dyes added to them such each layer will only be sensitive to one of blue, magenta or Yellow.</p>

<p>CD-4 (colour developer 4) is a Kodak invented developer agent that develops the silver just like a B&W developer but also triggers a dye bloom of the respective colour.</p>

<p>The silver is no longer needed at this point, so a bleach step returns the silver to an undeveloped state. When the fixer is applied, all the silver is removed and only the dyes remain.</p>

<p>If not enough bleach is applied or is exhausted, all the silver cannot be removed and the dye clouds will be covered. If the fix is exhausted the same will result. With blix, both of these situations will exist at some point.</p>

<p>The big thing here is that it has to be standardized to work correctly and the onus was on the film manufacturers to fine tune their film to make it consistent for the process to work, with no changes in the field.</p>

<p>Basic B&W Reversal.</p>

<p>1st developer is a string BW developer that develops a negitive.</p>

<p>A bleach (different kind than C-41) that bleaches and removes the developed areas of the film and leaves the undeveloped portion intact.</p>

<p>FLASH: This is simply exposing all of the remaining (positive portion) film with full intensity light for 1-2 minutes. It can be physical exposure or simulated chemically. </p>

<p>Normal development with a strong BW developer.</p>

<p>In a perfect world there is no fix required as the above step should develop all the remaining silver.</p>

<p>For colour slide film, the second developer (I believe) contains the dye activating components.</p>

 

[peterbcarter]

<blockquote>

<p>If there is a little shifting / colour bias would the scanner ignore it or would it treat it as if you'd been using a filter?</p>

 

</blockquote>

<p>You can. Ideally get a colour test card and photo shop / light room should be able to analyse it and create a setting to replicate for the rest of the film. For complete control, this is the way to go.</p>

<p>This will not help with bleach/blix failure. The problem here is the silver that remains will randomly cover dyes. Without consistency you cannot compensate. The good thing about this type of failure is you can always re-bleach and fix.</p>

<p> </p>

[peterbcarter]

<blockquote>

<p>where you developing by some guidelines or just experimenting? I bet you've made some good findings.</p>

 

</blockquote>

<p>No. But I do a fair amount of testing when I can. One thing that stuck was my displeasure of hot water baths. I have a motor base and the only temp it works off of is room temperature. Developing, as long as you are not using EKTAR, is perfectly fine at this temp; just a lot longer. BLIX really does not cut it very well.</p>

<p>All that being said, it is totally workable at room temperature and I don't think anyone would know if I didn't tell them.</p>

<p>I now use a divided form of developer which makes the developer last up to a year.....so far. If I could get my bleach to last that long......</p>

 

[ciaran_mcmenemy]

<p>Hi Peter, I really appreciate your answers! Thanks for taking the time to explain, I really mean it. <br />What films do you prefer to use, and what range of speeds?<br /><br />Have you done B&W reversal then? I was considering it, but I'm a bit unsure about adding sulphuric acid to potassium permanganate (I think those were one set of 'ingredients'). Although, it is diluted with water...<br>

I see what you're saying about blix. Does the fixer only fix the dyes? If it fixed the silver then it would be a race between it and the bleach. Are there any good home kits alternative to Tetenal?</p>

[peterbcarter]

<p>I enjoy the fuji superia, but I completely adored kodak portra 160 nc. Fuji's X400 is pretty good as well. I didn't like the EKTAR saturated colours, but it was almost grainless.</p>

<p>The fixer only removes undeveloped silver. The bleach process makes all the silver go back to the undeveloped state, so the fixer get's used heavily.</p>

<p>I did do a lot of BW reversal. There are a lot of steps with reversal so I tend to only use it whin I need stellar grainless images. I have documented some of it here http://myfilmstuff.blogspot.ca/2011/04/my-bw-reversal-process.html It needs an update, a project for sooner than later.. :)</p>

[Bill C]

"With regards to dumping blix, is it safe to put steel wool in it first? (Something like that is supposed to combine with the silver particles)."

 

That would probably work - basically the iron tends to "go into solution" in preference to the silver, which comes out. But the real question,

to me, is what will you do with the sludge? Refiners don't want such small quantities of an unknown material, and if you're just going to

throw it away, why bother to make the mess? (If you had a separate fixer, it's feasible to use something like the "silver magnet," a small

electroplating unit, and get reasonably pure silver flake that has some value.)

[peterbcarter]

<p>I have one of those "silver magnets" and they state not to use it with blix.</p>

<p>I'm guessing you would need to neutralize the bleach part first. I'm not a chemist, so I can't answer that one. I suspect the bleach would breakdown the steel wool before and silver-exchange magic could happen. But I really don't know for sure. Pro places use steel wool canisters but they don't use blix.</p>

 

[Bill C]

Hi Peter, that's exactly the problem with blix - it fights against the silver magnet, trying to "rebleach" the recovered silver. Fixer mostly

doesn't do this, so the silver magnet would work well in that case. Just not for blix. In order to electroplate silver out of blix, you need much

higher "current density," the amount of plating current per cathode area. (I know I said I haven't used blix, but I meant with respect to film; in

the case of PAPER, I've worked with blix quite a lot.)

[glen_h]

<p>I believe the Kodak numbers are three 36 exposure rolls per 0.25L, with increasing development times for each roll. Development time is important!</p>

<p>Bleach is an oxidizer, and oxidation from air is good for it. If you don't aerate it enough it won't last. I am not so sure about blix, though. Bleach and fix go to completion. If you do it a little longer, nothing bad will happen, and maybe some good. Also, you can usually rebleach and refix (and re-stabilize) later if needed. </p>

<p>If I remember E6 from years ago, the Kodak packs for home use had 16oz (about 0.5L) of most chemicals, but 32 oz (about 1L) of the developers. The Unicolor packs had 32oz of each. (In all cases, after dilution of concentrates.) But E6 does two rolls per 0.25L, where C41 does three.</p>

<p>You can probably stretch a little more, especially if you don't store the diluted chemicals for a long time.<br>

(In my E6 days, I would mix up the 8oz solutions and do two rolls sequentially. But only two.)</p>

[Bill C]

"Bleach is an oxidizer, and oxidation from air is good for it. If you don't aerate it enough it won't last. I am not so sure

about blix, though. "

 

Glen, I've worked with cine machines running C-41; we had to aerate in the processor to keep from losing bleaching power

(this is monitored with control strips). By contrast, this is NOT necessary with paper-process blix, so the implication is that

FILM blix would need to be MUCH stronger. When paper blix is aerated, as part of a regeneration process, much of the

sulfite ( which "protects" the fixer) is lost, so this must be replaced. From this background, I would imagine that the extra-

powerful bleaching portion of film blix would likely begin damaging the sulfite immediately (oxidizing it to sulfate), and the

fixer part of the film blix would be short-lived. Aerating the film blix would just speed up the destruction. Again, no

experience with film blix, just a somewhat educated guess.