Auto vs Manual Agitation (Chemistry Economy)

[analogphotog]

Can someone explain the difference in picture quality (if any) and chemical "efficiency" between a continuous rotary developing system and manual hand agitation with intervals?

I'd like to know how much less chemistry the rotary method will take. I am in India and I literally have one bag of unicolor powder kit to process after waiting for a year to import from USA. It is very hard to import c41 chemistry here, Any method at all to save the precious chemistry, I'm up for it. I know most of you would prefer if I use fresh chemistry and not try to cut corners here, but it's a proven method that continuous agitation will require less chemistry.

I'm planning to make a DIY machine that will regulate temperature and roll the tank automatically (in both directions) if it's going to consume less chemistry. Forgive my grammar, this isn't my first language.
I'll make a separate thread about the machine with the codes if I get to make it.

Right now I develop BW with my Jessops tank that can take 2x reels of 135. This is the tank I'm planning to automate also. It can hold 500-600ml of chemistry. I am waiting to start developing c41 until I decide on this matter.

Thank you.
I am very grateful for this forum.

 

[Sirius Glass]

I have used stainless steel and plastic tanks for many decades. When I went back to 4"x5" I tried trays and was not happy with that. I worked my way up from Yankee tanks to finally the Jobo 3010 Expert Drum, thanks to FreeStyles' patience and exchange policy. Once it started using the Jobo processor for 4"x5" sheet black & white sheet film, I was amazed at how consistently good the film developed. I then expanded to color and then 135 and 120. I have never looked back. Switching to using Jobo processing is the best thing that I have ever done to gain repeatedly great consistent film development and one of these days I will buy some more drums and start processing color prints. The cost is well worth it because once you switch, everything from then on will be done in the Jobo processor.

 

[analogphotog]

I have used stainless steel and plastic tanks for many decades. When I went back to 4"x5" I tried trays and was not happy with that. I worked my way up from Yankee tanks to finally the Jobo 3010 Expert Drum, thanks to FreeStyles' patience and exchange policy. Once it started using the Jobo processor for 4"x5" sheet black & white sheet film, I was amazed at how consistently good the film developed. I then expanded to color and then 135 and 120. I have never looked back. Switching to using Jobo processing is the best thing that I have ever done to gain repeatedly great consistent film development and one of these days I will buy some more drums and start processing color prints. The cost is well worth it because once you switch, everything from then on will be done in the Jobo processor.

That sounds dreamy I'd love to own a Jobo someday. As of now, a homemade version is what I can afford.
What about the chemistry? Do Jobo systems really only need half the amount when compared to manual development?

 

[AgX]

Manual vs. "Jobo"

Does not necessarily mean

Manual vs. Automated


One can rotary process by hand too:

-) along the edge of a table, with the top of the tank/drum off the table to keep things level
-) cross over a table on two slats or a board to keep things level
-) on a selfmade roller stand (board with 4 furniture rollers)


"Jobo" in the meaning of automated rotary processor is a american thing. When I hear "Jobo" I think of a Jobo tank.
(I assume because Jobo tanks were on the market here decennia before the Jobo rotary processors, whereas in the USA likely the Jobo tanks were introduced only with the processors.)

 

[analogphotog]

Manual vs. "Jobo"

Does not necessarily mean

Manual vs. Automated


One can rotary process by hand too:

-) along the edge of a table, with the top of the tank/drum off the table to keep things level
-) cross over a table on two slats or a board to keep things level
-) on a selfmade roller stand (board with 4 furniture rollers)


"Jobo" in the meaning of automated rotary processor is a american thing. When I hear "Jobo" I think of a Jobo tank.
(I assume because Jobo tanks were on the market here decennia before the Jobo rotary processors, whereas in the USA likely the Jobo tanks were introduced only with the processors.)

Apologies then. I did not know this.

 

[ic-racer]

I use a Jobo rotary processor mostly for convenience. For me it is the best way to process 10 rolls at once. Otherwise, nothing wrong with hand agitation for one or two rolls on an infrequent basis.

 

[analogphotog]

I use a Jobo rotary processor mostly for convenience. For me it is the best way to process 10 rolls at once. Otherwise, nothing wrong with hand agitation for one or two rolls on an infrequent basis.

Does continuous agitation need less chemistry than intermittent manual agitation?

With intermittent manual agitation, my tank is full with chemistry (550ml) for 2 rolls of 135.
I'm assuming this is because of the still periods where the tank will be upright and it has to cover both reels.
However while in continuous rotary agitation, since the tank is horizontal and is constantly in motion, I am assuming it would require less chemistry.
Can someone confirm this hypothesis? Someone who has used both methods?

 

[Sirius Glass]

That sounds dreamy I'd love to own a Jobo someday. As of now, a homemade version is what I can afford.
What about the chemistry? Do Jobo systems really only need half the amount when compared to manual development?

Each Jobo tank and drum states the minimum required chemicals.

 

[AgX]

Does continuous agitation need less chemistry than intermittent manual agitation?

The question should rather be: "does rotary agitation need less chemistry than inversion agitation?"
As even in inverting one can continuallly agitate, and actually often does at the start.

With inversion you need enough bath to cover all reels at vertical, top-up positon.
With rotary agitation you need less, typically at horizontal orientation enough to get the bath level to the core of the reels.

The rule of thumb is 2 to 1 bath volume relation between the two forms of agitation.


However this volume relation only applies at fully loaded tanks!
With a too large tank and inverting you can without problem only load 1 reel and only need the bath volume for 1 reel.
But loading a too large tank for rotary processing with only 1 reel, nevertheless will need bath volume for a fully loaded tank. (Unless you would make yourself displacers to substitute the missing reels. Moreover in a processor such tank with displacers would drive up.)

 

[MattKing]

I'd like to know how much less chemistry the rotary method will take.

Rotary processing can result in your using less chemistry for a very simple reason.
If you use inversion agitation, you need to have enough chemistry in the tank to completely cover the reels and film when the tank is standing still.
With rotary agitation, the reels and film are constantly moving through the chemistry, so you only need to have enough chemistry to cover a portion of the reels, and to supply enough chemical activity to develop the films in the tank.
That second amount is often less than the first amount.
The most economical approach by far is a replenishment line, but you need both high and consistent throughput, as well as equipment suited to it. Rotary processing presents problems with oxidation if you are using replenishment or any other system that requires re-use of chemistry.

 

[AgX]

For the volumes you can look up tables. For instance for the Jobo tanks.
However the current site is a mess, but there are old Jobo catalogs with tables and sole tables online.

 

[analogphotog]

Rotary processing can result in your using less chemistry for a very simple reason.
If you use inversion agitation, you need to have enough chemistry in the tank to completely cover the reels and film when the tank is standing still.
With rotary agitation, the reels and film are constantly moving through the chemistry, so you only need to have enough chemistry to cover a portion of the reels, and to supply enough chemical activity to develop the films in the tank.
That second amount is often less than the first amount.
The most economical approach by far is a replenishment line, but you need both high and consistent throughput, as well as equipment suited to it. Rotary processing presents problems with oxidation if you are using replenishment or any other system that requires re-use of chemistry.

I did not take oxidation into account. That does make sense. With the chemicals splashing around, it's a ground for quicker oxidation.
Do people who use the machines use their chemistry one-shot? This is a very practical take on the issue at hand. Thank you.

 

[pentaxuser]

Yes, analogphotog, your explanation of why you need less quantity of chemicals is exactly right. However you need to make sure you have used the minimum quantity of developer to ensure that the film will be properly developed. With some developers there is a minimum of stock developer required. Most minimum quantities of stock will still be enough for rotational development when the tank is on its side. The problem is only likely to occur with when the minimum developer quantity is large and you want to use a dilution of 1 of stock +1 of plain water which requires that a lot more liquid has to be poured into the tank and the tank is spun by a Jobo Processor which has an electric motor. This extra liquid may place a strain on the motor but will not be a problem if it is manual rotation

So my Jobo tank for a135 film uses 140 mls when on its side in a Jobo rotary processor but needs 240 mls when I use the same tank in an upright position and I agitate by inversion. So yes over the course of developing a lot of films you can save a lot of chemicals

pentaxuser

 

[AgX]

Do people who use the machines use their chemistry one-shot? This is a very practical take on the issue at hand.

It depends. Whether you use big open, vertical tanks and lead your film at hangers through it, or a tiny Jobo processor, the replenishment per film is the same for both cases (with same chemicals applied.) Thus with a Jobo processor the replenishment volumes can get near the min. bath volume per film. And then one might question replenishing as such.

 

[analogphotog]

Yes, analogphotog, your explanation of why you need less quantity of chemicals is exactly right. However you need to make sure you have used the minimum quantity of developer to ensure that the film will be properly developed. With some developers there is a minimum of stock developer required. Most minimum quantities of stock will still be enough for rotational development when the tank is on its side. The problem is only likely to occur with when the minimum developer quantity is large and you want to use a dilution of 1 of stock +1 of plain water which requires that a lot more liquid has to be poured into the tank and the tank is spun by a Jobo Processor which has an electric motor. This extra liquid may place a strain on the motor but will not be a problem if it is manual rotation

So my Jobo tank for a135 film uses 140 mls when on its side in a Jobo rotary processor but needs 240 mls when I use the same tank in an upright position and I agitate by inversion. So yes over the course of developing a lot of films you can save a lot of chemicals

pentaxuser

Thank you for that explanation. This is the perspective I was looking for.
I understand the added strain you're talking about with diluted dev, the motor's torque will be pushed to it's limit.
However Mattking has added a very valid concern of the chemistry oxidising at a higher rate in a rotary machine.

 

[analogphotog]

It depends. Whether you use big open, vertical tanks and lead your film at hangers through it, or a tiny Jobo processor, the replenishment per film is the same for both cases (with same chemicals applied.) Thus with a Jobo processor the replenishment volumes can get near the min. bath volume per film. And then one might question replenishing as such.

Ah, makes sense. I have a small 2 reel Jessops tank.
It's the same as Paterson System 4, I just checked.
The replenishment rate for 135 is 80ml/roll I guess.
However I was thinking about pouring the entire content from the tank back and increasing time on the now seasoned dev after the 8th roll.

For the volumes you can look up tables. For instance for the Jobo tanks.
However the current site is a mess, but there are old Jobo catalogs with tables and sole tables online.

Thank you! I'll look for them.

 

[MattKing]

I would suggest that you review this thread: https://www.photrio.com/forum/threads/how-much-do-you-get-out-of-kodak-flexicolor.175962/

 

[analogphotog]

Each Jobo tank and drum states the minimum required chemicals.

Thank you, Sirius Glass.

 

[MattKing]

Each Jobo tank and drum states the minimum required chemicals.

Thank you, Sirius Glass.

You need to be cautious with what it says on the tanks.
All they tell you is how much liquid is needed to physically cover the film.
With some chemicals, that amount may not supply enough chemical activity to do the work, even if the film is covered. For the minimum amount of chemistry needed, you need to pay attention to the Capacity information supplied by the manufacturer of the chemistry.
If, on the other hand, the tank requires a lot more liquid to cover the film than the amount of chemistry needed to process the film (the capacity), you end up wasting chemistry if you are using it one shot. It is in that situation where replenishment is most useful.

 

[Sirius Glass]

You need to be cautious with what it says on the tanks.
All they tell you is how much liquid is needed to physically cover the film.
With some chemicals, that amount may not supply enough chemical activity to do the work, even if the film is covered. For the minimum amount of chemistry needed, you need to pay attention to the Capacity information supplied by the manufacturer of the chemistry.
If, on the other hand, the tank requires a lot more liquid to cover the film than the amount of chemistry needed to process the film (the capacity), you end up wasting chemistry if you are using it one shot. It is in that situation where replenishment is most useful.

This is one of many reasons that I use replenished developers.

 

[Mick Fagan]

Does continuous agitation need less chemistry than intermittent manual agitation?

With intermittent manual agitation, my tank is full with chemistry (550ml) for 2 rolls of 135.
I'm assuming this is because of the still periods where the tank will be upright and it has to cover both reels.
However while in continuous rotary agitation, since the tank is horizontal and is constantly in motion, I am assuming it would require less chemistry.
Can someone confirm this hypothesis? Someone who has used both methods?

Firstly, welcome to the world of colour developing.

The real answer to your question is: it doesn't matter whether you use rotary developing or inversion for developing, the capacity of the chemistry is the same. I have developed thousands of C41 colour 135 rolls of film with rotary processing. I have also developed hundreds of rolls of C41 colour film using the same tanks but using inversion processing.

Essentially, the capacity of C41 chemistry is 8 rolls of 36 exposure C41 film per litre of chemistry. So your Unicolor 1 litre kit should be capable of processing 8 rolls of C41 36 exposure film very well. It is possible to develop more films, but degradation does set in, not to an alarming degree, but the more film you put through you will eventually see possible issues as you process more and more rolls.

I would suggest you make a very simple roller base so you can hand rotate your Jessops tank in a container filled with warmed water. Something like this would work perfectly well.
https://www.google.com/search?q=job...80#imgrc=g0-SgY_sMpSttM&imgdii=WM2CL83gdnhgeM

I don't know much about the Jessops tank, but from what I can see online and from your description of the volume you need, things should work out quite well. My main way of developing C41 36 exposure film was to use rotary processing in a Jobo 1540 tank, which holds 4 rolls of 36 exposure film and requires 500ml of solution. With this process I use a one shot developing system and develop 8 rolls of film using 1 litre of chemistry.

I am guessing with your Jessop tank, you could use 250ml of solution by rotary processing and develop two rolls of film at a time. This would mean you will realise the correct capacity of your chemistry for the first 8 rolls with the best possible developing outcome. After you have processed 8 rolls in the 1 litre, you could try developing 1 roll of film at a time using 250ml of used solution per roll. I think by using this method you will have another 4 rolls of film that should have pretty good quality. After 12 rolls of film I don't know as I've never done that, but I have done 12 rolls a few times around 30 years ago.

I would suggest you use simple glass jars, old jam jars or other foodstuff jars with a plastic coated underside lid will be very good and very cheap. Store new and used chemistry in jars like this and use glass marbles to eliminate air as much as possible. I have used this technique of glass jars and glass marbles (the same marbles) for over 40 years for both B&W and colour developing chemistry with great success.

Your Blix, which is a combination of Bleach and Fixing chemistry solutions, will have close to double the capacity of your developer, that is the good news. The bad news is that these are two different steps of film development chemistry and work against each other, so over time the solution becomes unusable. I looked at the Unicolor C41 instruction sheet, it is pretty good and their suggestions of over capacity seem right to me.

I would suggest you do the stabiliser bath, which is the very last bath, outside of the tank with the film off of the reels. I myself use a 500ml stabiliser bath in a 1 litre plastic kitchen jug. I take the film reel out of the tank, then pull the reel apart and drop the film on it's edge into the stabiliser for around 30-60 seconds. I then take the film out and hold it at an angle until the majority of liquid has drained from the film. I then place the film somewhere to dry. Do not rinse the film after the stabiliser bath, nothing should be done from the stabiliser bath.

When you hang the film up you may think you have done something wrong, it usually looks terrible. Just wait for an hour or so and you should find you have some pretty good negatives.

The correct time for C41 processing is 3'15" at 37.77 C (38C). I note that Unicolor give different temperatures for different ways of processing. What they seem to be doing is allowing for different methods used and how the different methods alter your ability to hold the colour developing bath at a constant 37.77C. Basically if you can determine what your start temperature is and what your finish temperature is and then calculate the median temperature best for your method that keeps the developing bath as close as possible to 37.77C is where you should be.

Once you have established a developing regime that works for you, things will be simple and hopefully your photographic world will be filled with vibrant colour images.

Mick.

 

[AgX]

I would suggest you make a very simple roller base so you can hand rotate your Jessops tank in a container filled with warmed water.

If you want to go safe on the temperature or do not want the hassle to start processing the moment the tempering bath is just on right temperature, you might mount a kitchen sous-vide heater at the tempering container.

 

[mnemosyne]

If someone goes the Jobo (processor) route, I strongly recommend using a lift setup. With manual filling of the tanks, I was not able to get consistent results with rotary development on the Jobo (CPE-2 in my case). A DIY processor will probably not include automatic filling/draining, so based on my experience I would recommend against it. The usual countermeasures like pre-rinse, stop bath etc. did not help in my case. Streaks and bubbles all the way ...

I am back to fully manual (small tank inversion). It makes sense for a small throughput scenario and can give very good and repeatable results. The cost of a processor left aside, the economics are worse than with rotary development (you need to double the solution volume) and the eco footprint is worse (more waste), but you can compensate by reusing the developer (might compromise quality depending on your personal idea of what is acceptable as result) or by replenishing the developer and reusing the bleach and the fixer (which will not compromise quality). Replenishing in a low throughput environment is possible as long as you keep your tank solution and replenisher air tight, ideally in EVOH based wine bag type containers. Also, the tank solution should have a reasonable (= not to small) volume, something in the 4-5 liter range.

The upside of inversion processing is that the larger volume required will give your tank much more thermal capacity and after processing temperature is reached, will make it much easier to keep the processing temperature within the temperature zone required. For the same reason I switched from stainless steel tanks to plastic tanks for color developing: It means less influence on the process temperature through variations in environmental conditions (ambient air temperature, water jacket temperature, temperature of your hands holding the tank ...). The downside is that because of their higher thermal capacity, plastic tanks need more pre-heat time.

 

[Sirius Glass]

If someone goes the Jobo (processor) route, I strongly recommend using a lift setup. With manual filling of the tanks, I was not able to get consistent results with rotary development on the Jobo (CPE-2 in my case). A DIY processor will probably not include automatic filling/draining, so based on my experience I would recommend against it. The usual countermeasures like pre-rinse, stop bath etc. did not help in my case. Streaks and bubbles all the way ...

I am back to fully manual (small tank inversion). It makes sense for a small throughput scenario and can give very good and repeatable results. The cost of a processor left aside, the economics are worse than with rotary development (you need to double the solution volume) and the eco footprint is worse (more waste), but you can compensate by reusing the developer (might compromise quality depending on your personal idea of what is acceptable as result) or by replenishing the developer and reusing the bleach and the fixer (which will not compromise quality). Replenishing in a low throughput environment is possible as long as you keep your tank solution and replenisher air tight, ideally in EVOH based wine bag type containers. Also, the tank solution should have a reasonable (= not to small) volume, something in the 4-5 liter range.

The upside of inversion processing is that the larger volume required will give your tank much more thermal capacity and after processing temperature is reached, will make it much easier to keep the processing temperature within the temperature zone required. For the same reason I switched from stainless steel tanks to plastic tanks for color developing: It means less influence on the process temperature through variations in environmental conditions (ambient air temperature, water jacket temperature, temperature of your hands holding the tank ...). The downside is that because of their higher thermal capacity, plastic tanks need more pre-heat time.

Even though my Jobo arrived with a broken lift arm, the lift is a must. It makes the whole process work very smoothly, especially the filling and the emptying.

 

[AgX]

If someone goes the Jobo (processor) route, I strongly recommend using a lift setup. With manual filling of the tanks, I was not able to get consistent results with rotary development on the Jobo (CPE-2 in my case).

Where do you see the shortcomings?

Jobo rotary processors had been in use at least 8 years before there was a lift and still thereafter lift-less models were offered.