Maximum through put of film in C-41 / Jobo processing
The Fujihunt documentation does not match the Jobo documentation, and the Jobo manuals seem more concerned with coverage than developer activity, so here is my question:
Using the ATL-2300 I can physically process five rolls of 220 film in one go using 1000ml developer, although I have not done so yet. Is processing the approximate equivalent to 800 square inches of film realistic? The very conservative Kodak documentation states one 220 film per litre, however I'm currently processing three 120 colour negative films at once in 470ml developer.
We have processed seven rolls of 135 film at a time using 800 ml of solutions, using Fujihunt 5 liter kit, with no problems. That is very close to your situation. You may need to use a little longer development time to compensate. I would say 10 seconds extra. Look at the Fujihunt kit instructions how much time has to be added after how many rolls: http://sorsa-tv.ath.cx/~antalh/fuji_ohjeet.jpg . These instructions state that when using 1000 ml to develop 100 ASA 220 rolls, you have to add 10 seconds after 3,2 rolls developed for the next 3,2 rolls. So, 10 seconds would make sense for six rolls as one-shot. 400 speed films would need about 15 seconds extra instead of 10.
Look at the replenishment rates from the Kodak documentation, it certainly will not say one liter per 220 but probably something like about 100-150 ml per 220. Check it out.
Have to say I'm a bit confused. I have exactly the Jobo 2300 as well.
No matter what dev, e6 or c41 I use I program the program I'm using, i.e., program 9, to the fill amount described on the specific tank I'm using, mine is 730ml.
NO TIME ADJUSTMENT!!!! Now, if the Jobo doc's suggest more then the 730ml for YOUR SPECIFIC tank model, i.e., 820ml then use that! Same if you are using the Duo Reel red tabs.
Again, the dev DOES NOT matter, follow the Jobo doc exactly and you will have a good day. The only execption to this rule is when running B/W's because of the different Devs and ISO's of course.
If you need further asst. please PM me.
Tom, can you post a few images to show the result? 3 120 rolls by 470 ml is equivalent to 3 220 rolls by 1 liter. I am sure many people, including myself, are anxious to find the real capacity of C-41 developer.
Originally Posted by Tom Kershaw
I own an ATL-2300 too. I failed to process 2 220 rolls with 850 ml of developer. In fact I had doubt about the result of processing 1 220 roll with 730 ml. I found Kodak's guideline of 1 liter for a 220 roll to be not too conservative. I hope I am wrong.
Before I own my ATL processor I used to manually process 2 135-36 rolls with 500 ml in a stainless steel tank. The result was always great. That was actually inline with Kodak's guideline. That's about 1 liter for 4 135-36, or 2 120, or 1 220 roll.
Hrst, the Fujihunt document you posted say: when processing professional films to maintain professional standards, use the developer only once: do not use time compensation.
While the table tells that you can process so many rolls of films by reusing the developer and by increasing the development time the statement also tells to not reuse the developer and not increase development time if you want to maintain professional result.
My interpretation of this Fujihunt document and Kodak's guideline is that the developer probably can develop far more films than the conservative 1 lier for 1 220 roll guideline. But for professional result (quality) the conservative guideline is the one to follow.
Perhaps this is why processing quality varied widely from minilabs that used to exist in every main street everywhere. Processing quality is really proportional to how the developer is overused. For the highest quality just follow Kodak's conservative guideline of 1 220 roll per liter. You can process more films but quality will decrease when the number of rolls increases. My personal experience has been 1 220 roll per 850 ml. I could not tolerate the quality loss by increasing the developer's capacity beyond this boundary. Again I hope I am wrong. I have not been able to process 2 220 rolls per process because of this capacity limitation. ATL-2300 allows a max of 1 liter per process despite that you can use different drums and those drums allow you to put as many as 10 220 reels in them.
Perhaps this is why all these ATL processors are discontinued today. They are really very low in throughput. If you own an ATL-1000 or ATL-1500, which use only 500 ml tanks, you really can not process 220 films and expect professional result.
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I do a roll of 220 in a ss tank with hand inversion with 450-475ml of Flexicolor developer without any problems at all.
the "conservative" (as you say) or one-shot amount for one 220 film is, according to Fujihunt instructions, 313 ml for 100 ASA, or 417 ml for 400-1600 ASA film. (Calculated from the table linked above.) That's still far from 1000 ml.
In any case, professional labs usually use replenishing procedure. The replenishment ratios are much lower than that. AND, replenishing is also a process that needs control. I would bet that many labs, even some calling themselves professional, just replenish without very strict control, maybe running a test strip once in a while, and that's same than just extending the dev time. But when extending the time, you do it only few times so it cannot go far away.
The point is that these one-shot tank volume minimum values have enough "safety guarantee" to develop the film to strict densitometric specifications regardless of exposure (eg.: underexposed roll exhausts the developer less rapidly and leads to overdeveloping with low solution volume), film type (some oxidize developer and/or release bromide/iodide more rapidly) etc. In a replenished system, the large volume of tank solution keeps this under control, and on average, the given replenishment ratio (per film) keeps the process somehow under control. So, to emulate this effect in one-shot environment, a bigger volume of developer can be used.
HOWEVER. If you know that your roll is properly exposed, and you know, that the results you get from this film are satisfactory to you (you can even do a test strip with it and measure!), there is no reason why you would need so much developer.
And, extending the time is a cheap but still completely usable substitute for replenishment at home. It's not 100% same as replenishing, but very comparable. But then, of course, there's the REAL limit for the chemistry. Look at the replenishment ratios KODAK gives! They are quite close to how many rolls can be made by extending time in small-tank processing.
Reusing by following the Fujihunt instructions WILL NOT cause any severe problems you would be feared of: it has no effect on grain, film speed, shadow detail, or anything like that. The chemicals are meant for these volumes and will work, but the exact densitometric control may be a bit off. But remember, it may be off to begin with because the differences in agitation style and tempering.
If you expose properly or take that in the account, I would guess you cannot see any difference in one-shot or two-shot or even three-shot, using the volumes given by Fujihunt.
Brucemuir, there is a big difference between your tank processing and Jobo rotary processing. There is a lot of air involved in Jobo rotary processing which can potentially cause the developer to oxidize significantly due to constant rotation of the drum and cause a significant loss of its developing capacity. However, some people have claimed that they followed Jobo's chemical volume guide, which suggests even less developer for a roll of 220, and got good result still. I seem to be the only one who have experienced the opposite that I have had many processing failures by using 730 ml or less developer for a roll of 220 on my ATL-2300.
Hrst, I will shoot a roll of 400VC 220 as soon as I can and use 500 ml of fresh chemicals to process it in my ATL-2300 again. I will report the result here when it's done. I already know that if I process it with 850 ml the result is excellent. Now I will test it with 500 ml (470 ml actually because ATL-2300 can not be set to 500 ml. 470 ml is the closest). I hope this will help in revealing the fact about the C-41 developer capacity question that seem never gets a real answer so far.
I am a newb at Jobo 2300 processing. Thanks to all the great contributors... I am curious... the only value of re-using develepor is to save on cost.... how much money is actually saved, expressed in rolls fo 220 or 35mm film? Just a ball park amount will suffice...
Ballpark, about 5 times lower cost for replenished developer, meaning that one could process 5 times more film. There are other "values", besides simply the immediate reduced cost. For example, a greatly reduced effluent load, or improved stability of developer activity.
the only value of re-using develepor is to save on cost.... how much money is actually saved...