The Effect of Different Methods of Agitation

[Benjamin]

Hello, I've done some reading on the net but I would be interested to hear some opinions from the folks here.

So how does changing the way that one agitates film during development affect the tonal range and grain of the negatives? I understand that more vigorous agitation will ltend to lead to more grain and contrast, but have little idea of the different methods of agitation, times etcetera.

I am currently using XTOL 1.1 with HP5 @ 400 & 1600 in 35mm and am starting to use FP4 @100 in 6x6 as well as Pan F @ 25 in 6x6 also.

So basically I wonder if I should change the way that I normally agitate my film I.e, 30 seconds of constant agitation followed by 2 inversions every minute, to get the 'best' tonality from the slower, 6x6 negatives?

I only ask because one only gets one shot with the develoment and I'm not wasteful with film or pictures.

Thanks and all the best,

Benjamin

 

[Phantomas]

Good one, I'm also curious to know. I've only started self-developing in January this year so do not have much experience (although *knock on wood!!* every roll turned out fine).

Just from what I hear (not making a statement) more agitation = more contrast and less agitation = better detail/tonality?

I've used ID-11 and currently use Rodinal. I agitate first full minute and then 3-4 inversions every minute. I'm guessing that would increase contrast? I think my recent shots are more contarsty than I'd like, should I go easy on shaking the tank?

 

[Roger Hicks]

More agitation = more toe speed at a given contrast; less = less. Film speeds are predicated on normal agitation. You are however looking only at fractions of a stop (maybe 1/3 at most).

More agitation = lower edge effects. You need to cut agitation a long way to get significant edge effects.

Otherwise, more agitation = more development at a given time, as does a higher temperature. For constant agitation the normal advice is to cut dev times by 10% to get the same contrast. For very low agitation rates, e.g. 'stand' development, dev times are often very long. Too little agitation can result in 'bromide streamers', uneven development marks on the film.

For ultra-critical sensitometric development, brush development is recommended, but of course this only works with flat film.

Agitation must be reasonably random or you can get streaking from uneven developer flows. This is especially true with constant-agitation tray developent of film, e.g. with a Paterson Orbital.

Frankly, an awful lot of nonsense is talked about agitation. The most important single factor is consistency: choose a regime and stick to it. After this, yes, there are variations, but at least half the people who get really excited about agitation would do a lot better to work on other aspects of their photgraphy first. Aesthetics, for a kick off.

Tashi delek,

Roger

 

[Murray Kelly]

I have to admit it is confusing to me, too. I've been developing films on and off for 60 years.
'Tis said that more agitation gives more contrast and for a low contrast result then 'stand' would be the better choice. All this is from reading, mind.
Therefore for microfilm such as TechPan etc the shadow detail can work up while the highlights are arrested by local exhaustion using a highly dilute developer.
Then someone gave me some Technidol for the copy film I have (Imagelink HQ) and I was surprised to see Kodak are adamant that it needs frequent and vigorous agitation and only for 7:30 @ 25 deg. Made me recall some advice I'd been given that the way developer gets into and laterally thru the gelatine really means that it doesn't actually matter that you agitate slowly for a flat result or often and fast for contrasty.
I had considered this heretical and ignored the sin, but maybe they're right?
As I said at the top - confusing indeed.
Murray

 

[bmattock]

Let's not make things more difficult than they are.

When you plunk your film in the developer, (or pour the developer into the tank with the film) it is essentially the same as putting a sponge in water. It absorbs the developer and begins the chemical reaction that ultimately results in a visible negative image being formed.

As the developer that touches the film and is within the 'sponge' becomes exhausted, it slows down and stops reacting with film's components. As a result, more time is needed for micro-currents in the developer to bring fresh developer into contact with the film.

Agitation and inversion serve the same purpose - to induce a more rapid exchange of fresh developer for stale as it contacts the film. This is a variable that must be controlled, if you want to maintain creative control of the development process.

That is, in normal development, developer dilution, temperature, and time are controlled based on established procedures (historical data). Given an 'average' agitation, development of the film should meet a standard, within parameters that are generally acceptable to photographers. More agitation results in faster development, and less results in slower development, within boundaries. This is why Jobo drum processors take far less time to process film than standard methods.

The key to agitation is consistency. Whatever it is you choose to do in the way of agitation, try to do it the same way and for the same period every time. Like dilution, temperature, and time, agitation will directly affect development times.

As to heel, toe, or calf development, I have no idea. I suspect that is best left to grain-peepers to discern. I know only that all things being equal (time, temp, dilution), more agitation equals more development, less agitation equals less development. That is an effect you're more likely to see with the naked eye than changing characteristic curves of various negatives processed with a widdershins agitation versus two inversions over a pentacle and a deosil tilt, then printed during the Ides of March or whatnot.

This stuff is not mysterious. Simple common sense.

 

[Murray Kelly]

I'm not sure we are helping the OP. He asks how agitation affects tonal range.
He is probably aware that all the factors below are best kept consistent. How agitation should be varied, if at all, and to what end is what he asks.
As I said, the Technidol experience flies in the face of all I have done and read about but does accord with the occasional advice I've received from people who do things a completely different way and get good results.
I'm a Beutler, stand, man myself from my early days but things have changed enormously since 1960! =:-0
Murray

Big snip
The key to agitation is consistency. Whatever it is you choose to do in the way of agitation, try to do it the same way and for the same period every time. Like dilution, temperature, and time, agitation will directly affect development times.
another snip

 

[Phantomas]

While we're at it, may I ask another question - what affect does dilution ratio has on the final result. At the moment, mostly due to inexperience, I dilute (Rodinal) randomly, sometimes 1-25, sometimes 1-50. I make the decision based on whatever development data is readily available and how fast I want to get out of the kitchen (subsequently choosing faster 1-25 dilution more often).

Can someone explain in one or two words what final results would highly diluted (longer developing) mix provide vs less diluted (faster developing)?

 

[bmattock]

While we're at it, may I ask another question - what affect does dilution ratio has on the final result. At the moment, mostly due to inexperience, I dilute (Rodinal) randomly, sometimes 1-25, sometimes 1-50. I make the decision based on whatever development data is readily available and how fast I want to get out of the kitchen (subsequently choosing faster 1-25 dilution more often).

Can someone explain in one or two words what final results would highly diluted (longer developing) mix provide vs less diluted (faster developing)?

Very general, because this is not true for all developers. However, in very general terms...

1) More dilution may increase accutance up to a point.

2) Longer development time means less deviation by percentage is likely.

What I mean by the latter is that a 10 second difference in development time means more in a 3 minute development than it does in a 10 minute development. Since pouring out developer and pouring in stop bath (or water) can take varying amounts of time, it is harder to 'be consistant' with shorter development times.

3) Cost savings. Less developer is less developer.

 

[CK Dexter Haven]

I'm interested in this too. I just yesterday processed my first film in 25 years.

I'm wondering what are the differences in agitation using Inversion versus the little "swizzle stick" rotating device in a Paterson plastic tank. Is one more 'dynamic' than the other? If i'm taking instruction and the recommendation is for inversions, do compensate somehow if i use the stick, or should i just do inversions? Any difference? Using the stick seems sorta like 'stirring.'

 

[sevo]

YMMV. There are developers where agitation won't change much (usually commercial hanging tank developers with a high concentration of active, depletable chemicals), developers where agitation behaves about proportional to time and temperature (most current multi-use low-grain developers), and some where agitation has effects beyond time or temperature, and will actually change quite fundamental aspects, like acutance and contrast moderation (typical for surface active low-concentration one shot developers). Some developers may belong to any group depending on concentration.

Sevo

 

[Roger Hicks]

I'm interested in this too. I just yesterday processed my first film in 25 years.

I'm wondering what are the differences in agitation using Inversion versus the little "swizzle stick" rotating device in a Paterson plastic tank. Is one more 'dynamic' than the other? If i'm taking instruction and the recommendation is for inversions, do compensate somehow if i use the stick, or should i just do inversions? Any difference? Using the stick seems sorta like 'stirring.'

Doesn't matter much. The only risk with the 'stirring' is over-uniform agitation, always turning at the same speed in the same direction. This can lead to streaking -- hence the advice to 'twiddle' to and fro. This is why Jobo CPE-2 machines reverse direction periodically.

Again, as long as you're consistent, it doesn't matter which you use. Greatly reduced agitation is mostly faddish; constant agitation is a matter of convenience in automatic processors. For the vast majority of applications, 10 seconds/minute or 5 seconds every 30 seconds is ideal. Take your pick.

You'll get far more variation in grain and tonality (and speed) with developer choice than with all but extreme variations in agitation (over 50% of the time in the direction of more agitation, or 2 inversions/minute or less in the direction of less agitation).

Tashi delek,

Roger

 

[bmattock]

I'm interested in this too. I just yesterday processed my first film in 25 years.

I'm wondering what are the differences in agitation using Inversion versus the little "swizzle stick" rotating device in a Paterson plastic tank. Is one more 'dynamic' than the other? If i'm taking instruction and the recommendation is for inversions, do compensate somehow if i use the stick, or should i just do inversions? Any difference? Using the stick seems sorta like 'stirring.'

It becomes a religious war quickly. Everyone has their own opinion, based on their own experience, and probably right as far as they are concerned because it works for them.

The point of ANY kind of motion, be it agitation or inversion, is to move the developer around, causing fresh developer to come into contact with the film, without causing bubbles to form (which cause uneven development).

Motion is motion. If fresh developer is coming into contact with the film, then there you go. How it got there doesn't matter.

The key is consistency. Once you find a method you like, stick with that and do it the same way every time. If you don't have uneven development, you're doing fine.

If you have questions about how well your method moves the developer around, try doing it with the top off and no film in the tank, or some junk already-developed film. Put a couple tiny bits off a styrofoam 'popcorn' ball we all have from previous eBay purchases in the water and watch to see where it goes. If it moves while you're doing whatever it is you're doing, they there you go. Well, it might be difficult to practice inversions that way, but you get the idea. The idea is to get the developer to move around. Other than that, there's not much magic to it.

 

[Roger Hicks]

It becomes a religious war quickly. Everyone has their own opinion, based on their own experience, and probably right as far as they are concerned because it works for them.

The point of ANY kind of motion, be it agitation or inversion, is to move the developer around, causing fresh developer to come into contact with the film, without causing bubbles to form (which cause uneven development).

Dear Bill,

Your post provides an excuse to add a few points that you are no doubt well aware of, but which others may find useful.

There is not much risk of bubbles sticking to the emulsion after the first few seconds, because they won't stick to wet film. Hence the advice to rap the tank sharply on the bench a few times to dislodge any, immediately after pouring the developer in, followed by fairly vigorous agitation for 15 or 30 seconds initially.

You need enough dev to cover the film, but for inversion, you also need an air-space over it: inversion is very inefficient in an overfilled tank. Consider inverting a full bottle of orange huice, and one that is 90% full.

As I have said elsewhere, and as you have forcefully implied, agitation variations only matter much when they are well outside the normal range of about 15-20%, whether that's 10 seconds/minute or 5 seconds every 30, inverting about once a second. Twice a second or once every two seconds won't matter much as long as you always follow the same pattern, and even then, variations will be minor unless you double or halve the overall agitation. Even then, they may not matter much.

But as you say, it soon becomes a religious war. Some people NEED to believe, not only in precision, but in their own interpretation of it.

Tashi delek,

R.

 

[bmattock]

You have gone totally digital...of course?

I don't want to speak for others, but in my own opinion, home development of B&W film is like being an audiophile, or a supreme-lens hunter, or etc. That is, there is a point of diminishing returns. I do what I enjoy and skip the rest. This horrifies the religiously-inclined damaged minds, which is fine with me. I'm a happy little heretic.

 

[bmattock]

There is not much risk of bubbles sticking to the emulsion after the first few seconds, because they won't stick to wet film. Hence the advice to rap the tank sharply on the bench a few times to dislodge any, immediately after pouring the developer in, followed by fairly vigorous agitation for 15 or 30 seconds initially.

My point about the bubbles was due to a memory of someone posting here "what's wrong with my film," and it turned out that his idea of 'inversion' and 'agitation' involved shaking the tank like a spray paint can. Those bubbles did not disperse...

But I take your point. Yes, by all means, tap the tank after inversions. 'Inversions' meaning a gentle up-ending and restore, not a vigorous shaking motion.

You need enough dev to cover the film, but for inversion, you also need an air-space over it: inversion is very inefficient in an overfilled tank. Consider inverting a full bottle of orange huice, and one that is 90% full.

Also true.

As I have said elsewhere, and as you have forcefully implied, agitation variations only matter much when they are well outside the normal range of about 15-20%, whether that's 10 seconds/minute or 5 seconds every 30, inverting about once a second. Twice a second or once every two seconds won't matter much as long as you always follow the same pattern, and even then, variations will be minor inless you double or halve the overall agitation. Even then, they may not matter much.

Yes. I find that just doing it the same way each time tends to produce predictable results, which can then be fine-tuned with regard to developing more or less in the future.

But as you say, it soon becomes a religious war. Some people NEED to believe, not only in precision, but in their own interpretation of it.

It is understandable, after all, it has worked for them. It would probably work just fine for others too. It can be hard to understand that there is more than one way of doing it and in the end, it probably matters less than they think.

I have seen more extremely-detailed descriptions of the angle of the wrist for the proper slosh and the height from which to 'tap' down the tank than anyone should have to withstand. From my point of view, how you do it matters less than that you do it, and even then, less than that you do whatever it is you do the same way to the extent you're capable of each and every time. Consistency over all.

 

[CK Dexter Haven]

Thanks, Bill and Roger.

But, i guess the answers above have prompted a new question....

If it doesn't much matter how you agitate, or how often, or whether it's by inversion or twiddling, why does it matter if you do it in a consistent manner from batch to batch? Although everyone acknowledges the method isn't critical, virtually everyone says it's 'important' to do the same thing every time.

[Does anyone have a mix/time recommendation for APX100 / Rollei Retro 100 in ID-11/D-76? I used the Massive Dev Chart's suggestion of 13.5m at 68-degrees. Nice results, but i expected finer grain, still, from this film, especially, having seen some lovely stuff on flickr using that film+developer combo....]

 

[bmattock]

If it doesn't much matter how you agitate, or how often, or whether it's by inversion or twiddling, why does it matter if you do it in a consistent manner from batch to batch? Although everyone acknowledges the method isn't critical, virtually everyone says it's 'important' to do the same thing every time.

It does not matter if you cook a turkey in an electric oven or a gas oven, but it does matter that you cook it. But a stated temp for a stated period should net you the same basic cooked bird results. You may find that switching back and forth between gas and electric stoves gives you different results - even though in both cases, the bird is 'cooked'.

So use the one you like and stick with it. Consistency in your oven will allow you to experiment with time and temperature and not have to always wonder if it was your oven that is the real cause of any problems.

I think I took the analogy too far. Now I'm hungry. Later!

 

[Benjamin]

If it doesn't much matter how you agitate, or how often, or whether it's by inversion or twiddling, why does it matter if you do it in a consistent manner from batch to batch?

If you follow a relatively strict process everytime, then when the time comes when something has gone wrong you have already limited the variables. This indoubtedly speeds up the process of identifying the problem.

Anyway, thanks to everyone for their replies to this thread. I knew that it might be a bit of battle but I don't much care. I just wanted to know if I should change my method of agitation when using slower, medium format films so as to help me get the best from the film before printing.

Cheers, Benjamin

 

[Murray Kelly]

Alas - as I'm at the other end of the world I am probably the only one awake.
I mentioned the Technidol example because Kodak give a completely different advice to their normal one of inversions at the wrist.

4. Provide immediate agitation by shaking the tank
vigorously up and down 10 to 12 times for 2 seconds.
Do not rotate the tank.
Liquid Developer Agitation Technique
5. Let the tank sit for 30 seconds, and then start the next
2-second agitation.
6. Repeat steps 4 and 5 every 30 seconds for the remainder
of the development time.

And they have a picture with the tank going up and down vigorously.
It's a pretty dilute working strength developer (1:13) - reminds me of some high dilution brews.
For interest I measured the pH and noted the colour before and after. The pH renained the same but the developer came out weak tea coloured indicating to me (at least) that even after 7:30 min of this kind of agitation, there was oxidation going on and leaving me to wonder of gentler agitation or stand would make a great difference to the final resulting tonal balance.

So Benjamin, maybe, yes, agitation style is important for the tonal balance of your film but only with diluted devs.
Murray

 

[maddoc]

Some interesting points, so far. Thinking about it, I started wondering what has more influence on the final negative, different methods of agitation or small variations in temperature.