Changing technique from agitation to inversions - how does it work?

Hi folks,

I've been using a Paterson tank with the 'twizzle' stick for the past year and a half for both B&W and C41 with good results.

I've decided to give metal reels a go after I've had nothing but issues with various brand plastic reels despite doing all of the tricks.

In absence of the 'twizzle' stick to do the usual agitations with metal tanks, is there a general rule of how it would work doing inversions instead when I'd have typically used the stick agitation method?

For B&W, I'm doing agitation for the first minute of development with the twizzle stick currently, and then inversions for X seconds each minute, how would it work for those bits?

For C41, the first 30 seconds of development, bleach and fix are all currently twizzle stick agitation, so I'd be interested again to see how it would work.

Apologies if this is a really stupid question but I've got my development down to a fine art, so I'm naturally apprehensive, especially as the twizzle stick agitation to start is all I've ever known.

Thanks!

You are in the UK, so it's likely you're using Ilford B&W chemicals. Here is Ilford's recommendation for agitation:


BTW, I've found that Hewes reels are excellent. They cost a little more, and are worth it.

Mark

Ilford's recommended scheme works great, Kodak had slightly different, invert every 30 seconds for 5 seconds .

For clarity, and because I expect not everyone has noted this, I take it you are asking about agitation for C41 colour film.

The challenge with colour C41 development is the required higher and more consistent temperature.
Metal tanks and reels are more susceptible to temperature drift problems if you are having to take them out of any tempering baths for extended periods of time, in order to agitate them.
Most of the documentation for colour processes is oriented toward commercial equipment, which generally employs either roller transport, dip and dunk with nitrogen burst agitation, or continuous rotary agitation.
However Kodak CIS-211 does give advice on using small tanks, including a useful diagram respecting inversion agitation: https://125px.com/docs/techpubs/kodak/cis211-2010_08.pdf

albada said:

You are in the UK, so it's likely you're using Ilford B&W chemicals. Here is Ilford's recommendation for agitation:

View attachment 370657
BTW, I've found that Hewes reels are excellent. They cost a little more, and are worth it.

Mark

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Thank you! My brain wasn't quite working last night when I posted this and didn't consider there may be differences between chemicals.

I'm using Rodinal for B&W and Fuji Hunt C41 chemicals for colour!

Thanks for the recommendation of Hewes, these are the ones I'm planning to buy. In the UK I can buy NOS 35mm ones for £20 a go, which is reasonable given I've spent nearly £15 for plastic ones that seize up.

mshchem said:

Ilford's recommended scheme works great, Kodak had slightly different, invert every 30 seconds for 5 seconds .

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Thanks! I'll check it out

MattKing said:

For clarity, and because I expect not everyone has noted this, I take it you are asking about agitation for C41 colour film.

The challenge with colour C41 development is the required higher and more consistent temperature.
Metal tanks and reels are more susceptible to temperature drift problems if you are having to take them out of any tempering baths for extended periods of time, in order to agitate them.
Most of the documentation for colour processes is oriented toward commercial equipment, which generally employs either roller transport, dip and dunk with nitrogen burst agitation, or continuous rotary agitation.
However Kodak CIS-211 does give advice on using small tanks, including a useful diagram respecting inversion agitation: https://125px.com/docs/techpubs/kodak/cis211-2010_08.pdf

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Thank you! Yes you are exactly right. I'm using Fuji Hunt C41 chemicals for colour.

My approach with C41 is 2 inversions every 15 seconds, so I'm not entirely sure if this will be a good thing or not when it comes to the steel tank but it was my sort of home version of continuous agitation!

I'll have a read of that link, many thanks

Agitation is a subject that gets people agitated, for whatever reason. But basically inversion is a form of periodic agitation. If the instructions say agitate for 10 seconds every minute, and you were doing that with the twizzle stick, you can do that with 10 seconds of inversions.

You can invert a Paterson tank too, you don't have to use that twizzle stick. Personally I think roll film tanks that cannot be inverted at all are crippled and inadequate (based on the tanks I had when starting out), but some people make it work.

Twotone said:

My approach with C41 is 2 inversions every 15 seconds, so I'm not entirely sure if this will be a good thing or not when it comes to the steel tank but it was my sort of home version of continuous agitation!

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Yeah, that'll work. I occasionally do color in a manual agitation tank and always do it like this. Agitate frequently to approximate continuous agitation - at least one agitation cycle every 30 seconds; a little more often doesn't hurt. I simply do inversions with a Paterson tank and between agitation cycles keep the tank in a tempering bath so it doesn't cool down too much.

With manual inversions, you have a considerable thermal mass (it takes quite some volume to submerge the reels, after all), so cooling down in the few minutes that development takes isn't all that much of a problem. You could try measuring the exit temperature of the developer (perhaps in a test run) and then adjust the start temperature so that the average works out as your aim value for the process you're running (e.g. 38C for C41, 41C for ECN2).

All this won't be quite as exact as a machine-run process, but it'll be "plenty good enough", at least in my experience. I mostly optically enlarge my color negatives; I figure as long as I get consistent results and don't run into problems with it, my film processing is good enough, even if it may not perform precisely "on spec". YMMV and all that.

For B&W I would recommend keeping your existing agitation regime when replacing twizzle stick agitation with inversions. This should give you roughly the same contrast. Invert slowly and rotate the tank about 90 degrees after each inversion.

Two inversions every 15 seconds for C-41 should be adequate. If you are concerned with temperature drift you can: (1) use larger tanks (at least 1L); (2) preheat the tank with loaded film(s) in the water bath. I prefer dry preheat (no presoak) but some C-41 kit manufacturers like Tetenal recommend presoaking water bath for several minutes.

The temperature drift is real. In my 1L Paterson tank I measured about 1 degree Celsius drift after pouring the developer into the tank that was not brought to the temperature (I was developing B&W film so I just extended the time accordingly).

Thank you everyone for your really useful responses, it makes me feel much more relaxed about it all!

For clarity, my intention is to buy a few metal tanks, but most notably one with a 2 X 35mm roll capacity. I already use a waterbath approach to help with temperature so I'll continue doing so.

The only aspects I'll change is swapping out the initial stick twist agitation for inversions (I already do inversions after the initial agitation), and unless I've confused myself this will be at the same quantity as before e.g.
30 seconds of 'stick' agitation = 30 seconds of inversions, with each inversion cycle (tipping upside down and then back) taking 1 second.

I would favour smooth and non-aggressive inversions over a focus on maintaining a 1 sec per inversion cycle approach, so will just go with what feels right.

One thing I've reflected on since developing, (especially with C41 colour) is that assuming the temperature is correct, it's surprisingly hardy when it comes to making mistakes. I've had 3-4 rolls in around 90 rolls or C41 colour go wrong, and they've been down to silly errors like not the waterbath not being deep enough etc.

Thanks everyone

Twotone said:

I would favour smooth and non-aggressive inversions over a focus on maintaining a 1 sec per inversion cycle approach, so will just go with what feels right.

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The latter is a good approach by any means. Neither smoothness nor a 1-sec agitation cycle are very crucial. Agitation may be brisk as long as it doesn't unsettle the film from the reel, and in a color process, any agitation scheme that sufficiently approximates constant agitation will in practice work just fine. After all, as you said:

Twotone said:

it's surprisingly hardy when it comes to making mistakes.

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Very much agree with this.

When I help newbies learn this sort of stuff in real life (not on the internet) I get them to hold a tank in both hands - one palm on the top of the tank and the other palm on the bottom.
I get them to first hold the tank upright that way, and then turn their hands so the tank ends upside down, and then reverse the action so the tank ends up right-side up again. While doing so, I tell them to observe how the tank both turns over and rotates, due to how it is held.
That combination of both rotation and inversion is exactly what you want! It maximizes the value and randomness of the agitation, while still permitting you to adjust the intensity between gentle and aggressive, as needed.
One caution: particularly with colour chemicals and steel tanks, you want to wear good gloves. Steel tanks often leak a little bit more than a well sealed Paterson Super System IV tank.
The other thing I recommend to newbies is that they listen to the sound of liquid moving during the agitation - there should be just enough air in the tank to create enough cavitation during agitation that you can hear it gurgle.

Twotone said:

Thank you everyone for your really useful responses, it makes me feel much more relaxed about it all!

For clarity, my intention is to buy a few metal tanks, but most notably one with a 2 X 35mm roll capacity. I already use a waterbath approach to help with temperature so I'll continue doing so.

The only aspects I'll change is swapping out the initial stick twist agitation for inversions (I already do inversions after the initial agitation), and unless I've confused myself this will be at the same quantity as before e.g.
30 seconds of 'stick' agitation = 30 seconds of inversions, with each inversion cycle (tipping upside down and then back) taking 1 second.

I would favour smooth and non-aggressive inversions over a focus on maintaining a 1 sec per inversion cycle approach, so will just go with what feels right.

One thing I've reflected on since developing, (especially with C41 colour) is that assuming the temperature is correct, it's surprisingly hardy when it comes to making mistakes. I've had 3-4 rolls in around 90 rolls or C41 colour go wrong, and they've been down to silly errors like not the waterbath not being deep enough etc.

Thanks everyone

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4 reel tanks are great, but I imagine for C-41 you have to consider costs.

With metal you can rap that tank hard to dislodge bubbles. Sometimes I feel sorry for my neighbors.

Turbulence! The twizzle doesn’t give you much of that, and you need to disrupt the laminar layer when you are trying for effective agitation.

Stand processing intentionally minimizes disruption of the laminar layer but that’s another technique.

When I do the Kodak agitation scheme, I change from every thirty seconds to every minute after about 14 minutes if I am processing for extended times up to 48 minutes (when graphing curve families)

Bill Burk said:

4 reel tanks are great, but I imagine for C-41 you have to consider costs.

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When using 1L C-41 kits I find it more convenient and cost-efficient to use a 3-reel Paterson tank with 1L capacity. I mostly develop medium format and it is ideal to process 4 films (loading 2 on one reel).

Hi folks,

I've successfully developed a few rolls of B&W in my 2-reel Nikor tank however I'm now looking to carry on with C-41 at home as I've got a lot of chemicals to use. The reels are much nicer than that Paterson ones, and I no longer am concerned about whether or not the reel is going to jam and ruin the roll!

My plan is to use a 3 or 4 reel steel tank (whatever I can find) so it can go in the deeper waterbath with the chemicals, otherwise if I use the smaller tank I I imagine this will be too unstable if floating especially as it leaks a bit so would be concerned about water ingress into the chemicals - feel free to correct me if this assumption is incorrect!

I'd fill out the remainder of the tank with empty reels but essentially develop 1 or 2 rolls at a time with enough developer to cover the 1 or 2 rolls.

If anything I'm planning to do is incorrect or if anyone has any other tips please let me know!

Thanks

Twotone said:

floating

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I used to weigh down my Paterson tank with something like a brick or so when I started out doing color in a tank in a water jacket.

Your plan is good. As described in a different thread I use a 40L cooler container (insulated) for a water bath. A drying rack (bakers use them) at the bottom improves circulation of the water bath and provides a stable flat surface. I use a cheap sous vide to maintain temperature. I fill the container with enough water to cover about 3/4 of my 1 L Paterson tank. Stainless steel tanks are heavier so you can fill it a bit more. All the chemistry in bottles goes in the water bath together with the tank loaded with film (no prewash at this stage). My system comes to equilibrium in about 30 minutes. Check the temperature of the developer (not the water bath) before starting the development. The timing, agitation and temperature are most critical for the development stage, all the rest of the process goes pretty much to completion.

Agitation is by inversion, very frequent. The tank returns to the water bath between agitations. With 1 L of solution in a steel tank you don't need to worry about temperature drift.

Do not overthink it. The process is not much harder than B&W. I got it right from the first attempt. Where I live (Down Under) home development is not much cheaper than sending film to a lab, so I don't develop at home any more. It is great fun though and I recommend you try at least once.

koraks said:

I used to weigh down my Paterson tank with something like a brick or so when I started out doing color in a tank in a water jacket.

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Or put that something-like-a-brick under your tank so it does not float.

Thanks Both

To be clear, I already develop C41 but have done so with Paterson tanks previously which are longer (even the 2 reel tanks) than the smaller Nikor 2 reel tank I'm talking about, so I'll do as suggested and create a pedestal for the tank to sit on in the water to allow it to be submerged without running the risk of water getting inside it through where the top portion slots into the bottom half (it leaks on inversions slightly, so I imagine water could also get into the tank too).

Will report back once I've tried it out!