C-41 +1 in Jobo 1520

koraks

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Old Gregg said:
you asked a question here, and then you attack people who try to answer instead of saying "thank you, koraks".
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Oh, no worries, I'm not hurt or anything and I actually do understand the responses I got. It's perfectly fine. If you have a plan in mind and someone points out its weaknesses it's never nice at first. I've been in the same position thousands of times. Regarding color processing, I really learned this the hard way. It's soooo much EASIER to just do it by the book instead of fudging it and then having to troubleshoot - which often is impossible if you don't run by the book; as witnessed by roughly one thread a week on here with 'mystery' C41 problems. Trust me, I've cut just about every corner I could find - reusing store-bought developer, mixing my own, developing at lower temperatures and longer times, intermittent agitation, DIY water jackets, DIY bleach, DIY fix, replenished or reused fixer etc. etc. etc. etc......What WORKS is to do it by the book, at least for the developer. With bleach and fix, there's plenty of room to experiment or modify variations. But proper use of C41 developer is walking a fairly narrow path with a ravine on both sides of it.
 

koraks

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Wayne said:
Instructions state 4 inversions every 30 seconds. How does that equate to continuous?
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It's close enough according to the confectioner of the developer to continuous to hope/trust/pray that it will give good results. It's a balancing act - if they would say '10 inversions per 30 seconds', people would take the tank out of the water jacket too long and the contents would cool below the target temperature too much. If they said "4 inversions per 60 seconds" they would get complaints from people with unevenly developed film. The 4/30 they mention is a compromise between these two. It may or may not work for you - you may still run into cooling problems and in case you happen to do 120 or 4x5 film you may run into uneven development issues. Try it and hope for the best.

Don't forget that companies like Unicolor/CineStill c.s. have no choice but to deviate from C41 process parameters because those are often not attainable by home users, except perhaps if you have a fancy Jobo machine etc. As a result, the process they describe will always be compromised - but in practice this is often not a problem because 99.5% of the home users will scan their film, run it through Photoshop etc. and make them 'look pretty' that way. If the development is on target is in practice often lost in the noise of amateur post-processing. If teh colors come out a little funky, just twist some sliders in Photoshop or call it 'vintage' and all is well. I'm not saying this is bad, or should not be done - it's totally fine. If it works for you, be happy and enjoy the leeway it gives you in film processing! I can only say it did not work for me - admittedly partly because I like to shoot C41 to print RA4, and that means the negatives need to be as good as they can be. But even if you end up scanning your film, it's much easier to get a decent result if the negatives are good to begin with.

Wayne said:
At roughly 30 bucks per liter that's 7.50 per roll. A lab could do it for less than that. Seems like a waste of time and money.
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I agree with you that kits like Unicolor's are a waste of money. I concluded this a few years ago as well. Hence my earlier suggestion to look elsewhere.
 

RPC

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C-41 does not require continuous agitation, and the process was not designed specifically for it, although it works if done right, as does intermittent agitation. The Kodak z-131 literature discusses intermittent manual and gaseous burst agitation for use in lab processors and tanks. Nowhere does it say continuous agitation is needed.

As for development in small tanks, this Kodak PDF describes a way to agitate for small tanks:

kodak CIS-211 (Using Kodak Flexicolor Chemicals in a Small Tank).pdf

This assumes Kodak chemistry but may work for other brands. The point is, even Kodak recommends intermittent, inversion type agitation.

EDIT: link may not work, see Wayne's post below.
 
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RPC

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I simply invert my tank (stainless steel, with water bath) every 10 seconds, rotating it a little. I get consistent, uniform results; I check every roll with a densitometer.
I mostly do 120, but with 35mm I put two 35mm reels in a 120 tank with 1 or both containing film and fill with developer. I never have any uniformity problems.

The referenced developer was standard C-41 developer, probably called "SM" or "Small Tank" developer due to the small amount (2 liters} it made.
 
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RPC

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In the 15 years I have been here I have seen many posts of people who have problems with rotary agitation; streaking, spotting and problems getting the agitation speed correct to give desired results, as many or more as those who use intermittent/inversion. No method is better than another if you work out whatever problems you may be having with that method as both can give good results.

My first post was not to argue that one method was better than another, but that the claims made that C-41 needs continuous agitation are simply not correct.
 
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pentaxuser

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RPC when I click on your link to the Kodak doc, I get an error message that it cannot be found.

Thanks

pentaxuser
 
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Wayne

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Still waiting for you to either show me or retract your absurd accusation.
 

RPC

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pentaxuser said:
RPC when I click on your link to the Kodak doc, I get an error message that it cannot be found.

Thanks

pentaxuser
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Sorry, for some reason it works with my Opera browser but not Firefox or IE. Thanks Wayne for the link.
 
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pentaxuser

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Thanks Wayne and RPC for your help. An interesting doc in which Kodak clearly states that inversion in the correct circumstances is fine. I presume that Kodak tested this and found it to deliver results that are just as good as continuous rotational agitation in which the film is never completely covered all the time, based on the Jobo amounts of developer. It would appear that as Kodak makes no mention of using half the required developer as per Jobo then in its process the film is always completely covered. This would appear to be borne out by the fact that it mentions 500ml which I assume is the amount used.

My assumption is that what Jobo has done is test its 50% process( i.e. using 140 ml for 135 film instead of the 280 ml required for total immersion) and found this to be equally fine.

A reasonable conclusion might be that while the Kodak method does not achieve constant agitation, it does achieve constant immersion and this latter fact may compensate for the lack of constant agitation. In other words constant agitation per se is not the vital difference

What follows from this, I think, is that based on the Kodak cycle of intermittent agitation, then in effect filling the tank completely and using rotational agitation should allow the user to stop and start the Jobo rotational agitation as per the Kodak cycles and then find no difference between the inversion cycle and the rotational agitation using the stop/start as per the stop/start mentioned in the line above

Certainly on the basis that the Kodak inversion cycles are frequent and have presumably been tested by Kodak before publication of its doc I am struggling to see why the Kodak method and Jobo constant agitation method differ enough to make one method better than the other

Now pre-wet or no pre-wet are two entirely different things of course and one leads to heaven and the other to hell

pentaxuser
 
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Wayne

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Old Gregg said:
Why would I? It's like explaining a joke. Just keep reading your posts until you get it. Hard work produces results, trust me I'm a doctor.
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In other words you can't, because I didn't. Thank you for proving where the problem actually lies.

The fact is, Old Gregg, who is new here and hides his posting history, I have been here interacting with Koraks for a decade and a half and never had any problem. The fact is, Old Gregg, who is new here and hides his posting history, I have a great deal of respect for Korak's opinions and advice and would never "attack" him. Expressing my opinion and trying to have a discussion to clarify it is hardly an attack.
 

mtjade2007

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From my past experience C-41 films do not respond well with push processing. If the film is under exposed no amount of push process can bring back lost shadow. Rather, it will only cause color crossover to the film. You will realize it's a waste of film and chemicals to push C-41 film.
 

mtjade2007

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pentaxuser said:
Now pre-wet or no pre-wet are two entirely different things of course and one leads to heaven and the other to hell

pentaxuser
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It's important to know pre-wet could dilute the developer significantly. JOBO processor users tend to use the minimum amount of developer required so they could be closer to hell than to heaven as a result. I pre-wet my films but I always use the max possible amount of developer, 1 liter for 4 220 rolls as an example. Use 500 ml for 2 220 rolls rather than 250 ml for one 220 roll then repeat. Always happy in heaven.
 
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mohmad khatab

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In fact, I would love to participate in this discussion.
I have noticed that rotational agitation is indeed very beneficial.
I had an Indian tank that didn't have an induction stick
In the development of black and white there were no problems, but with the development of color film,, there are problems.
I invented and planted a stir stick for this Indian tank.
It wasn't difficult.. I just heated up a tiny little nail and inserted it into the shaft horizontally, and confirmed this implant with epoxy double laminated putty in order to confirm that the screw didn't move and then I brought a piece of galvanized iron (actually it was my antenna for an old radio) and I cut a part of it and made an incision on one end with a precision iron saw
I installed the film with the tank, and then I inserted that stick into the tank and threaded the stick with the screw. At first, it was a little difficult to thread the stick with the screw, as the slit in the stick needed some expansion, and little by little, it was normalized and I stimulated.
It worked very well
I can photograph that experience or bring the pictures to you later.
- The stainless steel tank and any tank that does not have a stir stick. I consider its use in developing a color film to be very risky. These tanks were not designed to develop a color film by flipping, and it can be worked in the summer, as the room temperature in Egypt is 39 degrees in summer, and therefore even if you develop without a container of warm water, there is no problem
 

pentaxuser

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mtjade2007 said:
It's important to know pre-wet could dilute the developer significantly. .
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Thanks for the reply. The comment was meant as a joke which alludes to the often "do or die" state when we get into on Photrio when "sacred cows" such as pre-wet or no pre-wet are discussed. That's why the smiley face was attached

It's just me and whimsy at work but usually for the honourable reason of trying to lighten the mood that gets us, at times, close to the gunfight many years ago at Tombstone. Cue Frankie Laine

pentaxuser
 

mtjade2007

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Thank you too for explaining. I could not stop stepping into the pre-wet or not, because it is something JOBO users often ran into. Have a good day Pentexuser.
 

Adrian Bacon

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I switched over to replenished Flexicolor chemistry in a JOBO several months ago to reduce my chemical usage because I’ve been having a hard time getting a solid supply of chemistry and starter solution at the usage levels I’ve been at and I run control strips (and recently went to the expense of getting a color densitometer) and I can’t say that has been my experience with replenishing. My working solution is a gallon and I run 3 36 exposure or 3 120 rolls, or 4 24 exposure rolls per 600ml and if anything, the control strips have gotten more stable over time. Of course, my usage is not typical home user levels. How many rolls per month were you running, and where you replenishing per the emulsion data sheets? Believe it or not, that does make a difference and matters. It’s not just a simple matter of generously replenishing. You really should replenish per the data sheet, and really should monitor the process, otherwise, how do you know if you were even in spec to begin with?

granted, you found a solution that works for you, which is great, but being a jobo user, I’m always curious about specifics of other jobo users setups and experiences relative to my own.
 

sillo

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pentaxuser said:
Now pre-wet or no pre-wet are two entirely different things of course and one leads to heaven and the other to hell
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Well just to add some fuel to this fire, I found my results are visibly better doing NO pre-wet in a Jobo. Specifically lower contrast (as in better my prewet negs were extremely contrasty) and much more neutral colors. When I compare prewet vs no prewet negs the highlights are very dense when using a prewet and my rebate text is much darker than both my lab developed and no prewet developed rolls.

Kodak specifically calls this out in their documents to not prewet so it must mean something. I'll try to dig it up also, but PE (who always said he used a prewet) had a post a while back about what all that stuff is that comes out when you do a prewet and his list seemed rather important to the development process.
 
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mtjade2007

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Thanks for finding that post. It is a good one. Lots of expert information.
 
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