Agitation When Developing Film

[RayD28]

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I recently developed a role of HP4 shot at box speed using the Massive Development Chart's recommended time.  The developing time, mixture, and temperature was the same as I always use.  The only thing different was the number of inversion and technique.   I normally invert four times at what I call slow and gentle inversions.  The last role I developed I made six or seven inversions that were less gentle than usual.  Several shots on the roll had blown highlights but the shadows were great with good detail.  It's possible that I screwed up the exposure when taking the shots but I usually lose shadow detail when I make an exposure error.  

My question is, how does over agitating during developing affect the finished film.  All responses appreciated.  

 

[blackandwhite]

Actually Ilford HP4, 125 ISO is quite a "fexible" film. I devellop it in Rodinal (still have a stock of original Agfa Rodinal) and I inverse gently but constantly the first 40 seconds, then every minute three times gently. Except when I do long time still stand developments ( Rodinal 1:100 for one hour, sometimes even 10 minutes more). In that case, I inverse for one minute in the beginning, then 3 times after 30 minutes. Always with nice results. There is no "absolute truth" in bw film development, as one gets on one hand what one looses on the other. More contrast means less details in the shadows. Also developing temperature is important and one cannot always contol it, especially in summer.

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[Tom R]

I am NOT a chemist (but I'm willing to bet that several contributors to this forum are). This  being said, from what I have observed, film developers work at a particular rate, depending to some extent, upon the relative areas of exposure: maybe it is the case that those areas of the film that received more exposure exhaust the developer quicker than those areas receiving less exposure (?).  When you agitate, you replenish the developer across the entire surface area of the film and that has the effect of favoring the highlights (more exposed areas of the film) while short-changing the shadow areas. Another way of thinking of this: over-agitation exaggerates the film's intrinsic characteristics.

That being said, I am hopeful that at least one chemist will follow-up with a more thorough (and perhaps more correct) explanation. (Somewhere in the back of my head I recall something about the "Kendal" series or some such thing that provides a more complete chemical analysis of the film development process.)

At the end of the day: unless one has a reason to do otherwise, respect the recommended standards and focus on why you're making pictures in the first place. 

[Stuart Richardson]

All else being equal, increased agitation typically increases contrast for the reason Tom mentions. You are constantly flushing new developer into the areas that contain exposed silver, so the developer does not get the chance to locally exhaust ( local exhaustion in effect "compensates" for increased contrast in the scene). If you have contrasty light and a contrasty film and agitate a lot you will get very contrasty film. Like most things darkroom, the data sheets from Kodak and Ilford generally have excellent information, as they are put together by the scientists who made the film and chemicals. Ilford recommends ten inversions per minute at the end of each minute, and Kodak recommends 5 every 30 seconds. I have run a lab for 15 years (mainly printing, but lots of hand developing too), and rarely have I found that the times and info from Ilford and Kodak to be unsatisfactory. In most things in film developing it is best to control as many variables as possible and keep things consistent, and rather change things in camera rather than in process. Once you dial in good results it seldom makes a lot of sense to change them unless the circumstances require it. If you want to have increased shadow detail in your film while preserving your highlights, try rating your film a bit slower and cutting back slightly on development. Shoot your HP5 at 320 or 250 and cut your development by 15% and see what happens.

[RayD28]

1 hour ago, Stuart Richardson said:

All else being equal, increased agitation typically increases contrast for the reason Tom mentions. You are constantly flushing new developer into the areas that contain exposed silver, so the developer does not get the chance to locally exhaust ( local exhaustion in effect "compensates" for increased contrast in the scene). If you have contrasty light and a contrasty film and agitate a lot you will get very contrasty film. Like most things darkroom, the data sheets from Kodak and Ilford generally have excellent information, as they are put together by the scientists who made the film and chemicals. Ilford recommends ten inversions per minute at the end of each minute, and Kodak recommends 5 every 30 seconds. I have run a lab for 15 years (mainly printing, but lots of hand developing too), and rarely have I found that the times and info from Ilford and Kodak to be unsatisfactory. In most things in film developing it is best to control as many variables as possible and keep things consistent, and rather change things in camera rather than in process. Once you dial in good results it seldom makes a lot of sense to change them unless the circumstances require it. If you want to have increased shadow detail in your film while preserving your highlights, try rating your film a bit slower and cutting back slightly on development. Shoot your HP5 at 320 or 250 and cut your development by 15% and see what happens.

So over agitation could result in blown highlights?

[Tom R]

Well, taking into account the responses up to this point, I'd say a qualified "yes." But, again, agitation is one element of the development process, others are temperature, dilution, total time in the developer, and, of course, the original exposure and intrinsic scene contrast. Given this considerable number of things to ponder, I find it best to "standardize" my process thereby freeing up time and energy to apply to the bigger problems, such as why this image, and so forth and so on. After all is said and done, a technically perfect picture, processed flawlessly, is worthless unless it "works"--whatever that might mean to you.

Edited May 14, 2021 by Tom R

[david strachan]

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Hi Ray

I'd go with Stuart's advice to decrease time by 15%.

I use FP4+, my choice of B&W film for last 25 years, or so.

I use a Jobo Multi Tank System 2500 (no 2551) which takes five rolls of 35mm film at a time, or a Paterson Multi Three Reel .  I put it onto a Simmer Roller (Made in Ontario, Canada) which rolls the Jobo in a sinusoidal manner to ensure even mixing of chemicals through the development process. Even develop at tap water temperature of 13 degrees Centigrade through winter, here in Adelaide out in the shed.

I use the instruction pamphlet for Ilford FP4+ (search internet) and made sure of corrections for temperature and continuous agitation, noting the developer and dilution, was Ilfotec LC29...set stopwatch, pour coffee and just sit nearby to watch rolling Jobo for 30 minutes.

 

Now haven't done any developing for a couple of years...but do remember the  reduction in time due to continuous agitation was 15%. Perfect negs after Photoflo-200 and squeegee, hang drying.

Best way is to do some experiments yourself.

Good luck.

 

 

Edited May 14, 2021 by david strachan

[250swb]

19 hours ago, RayD28 said:

I recently developed a role of HP4 shot at box speed using the Massive Development Chart's recommended time.  The developing time, mixture, and temperature was the same as I always use.  The only thing different was the number of inversion and technique.   I normally invert four times at what I call slow and gentle inversions.  The last role I developed I made six or seven inversions that were less gentle than usual.  Several shots on the roll had blown highlights but the shadows were great with good detail.  It's possible that I screwed up the exposure when taking the shots but I usually lose shadow detail when I make an exposure error.  

My question is, how does over agitating during developing affect the finished film.  All responses appreciated.  

 

I think you answered your own question, if it worked before and doesn't work now and only one thing changed, that's the thing you are looking for.

Yes, vigorously sloshing fresh developer over the film does increase contrast. This is why you only agitate once every minute, to allow the shadows to catch up and to make the highlight development slow down. The highlight areas exhaust the developer first, so allowing the exhausted developer to sit undisturbed in those areas it acts as a buffer, which means vigorous or extended agitation cancels this buffering effect and over-develops the highlights. You can use increased agitation and fresh developer if you want high contrast negatives, or alternatively if you want maximum tonal information you can go the other way and use semi-stand or stand development to maximise the buffering effect of exhausted developer (but use a developer that's good for this technique).

Edited May 14, 2021 by 250swb

[RayD28]

Lesson learned.  Thanks for 

4 hours ago, 250swb said:

I think you answered your own question, if it worked before and doesn't work now and only one thing changed, that's the thing you are looking for.

Yes, vigorously sloshing fresh developer over the film does increase contrast. This is why you only agitate once every minute, to allow the shadows to catch up and to make the highlight development slow down. The highlight areas exhaust the developer first, so allowing the exhausted developer to sit undisturbed in those areas it acts as a buffer, which means vigorous or extended agitation cancels this buffering effect and over-develops the highlights. You can use increased agitation and fresh developer if you want high contrast negatives, or alternatively if you want maximum tonal information you can go the other way and use semi-stand or stand development to maximise the buffering effect of exhausted developer (but use a developer that's good for this technique).

Lesson learned.  Thanks for explaining.  

[Ornello]

Use a tank that has a tight lid. Fill the tank almost all the way to the top. In other words, do not put just enough developer to cover the roll! After the developer has been poured in, agitate for roughly one minute by inverting the tank and rotating it gently! Gently! After one minute, invert and rotate the tank twice, once each minute. 

If you do not fill the tank all the way up, the developer will slosh around too much, causing uneven development.

Try to avoid developing times under 6 minutes. 10 minutes is ideal. Dilute your developer until you find that 10 minutes gives a good negative for printing.