beginner's agitation questions

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ulrich.von.lich

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Hello,

I'm just starting to develop B&W films and I have some questions about agitation.

1. Should the chronometer be started after the developer is poured into the tank and top cover is closed?

2. For example, "5s every 30s", I interpreted it as 5s + 25s + 5s. Is it correct or should it be 5s + 30s + 5s?

3. "initial agitation 30s, then 10s every minute": does the "10s every minute" start right after the initial 30s or after the first minute?

4. How fast should be an inversion be done? And will the speed of the agitation (not the amount) affect the result?

5. Should the tank be twisted during inversions?


I'm sorry if the questions sound silly.

I understand in reality the agitation (or the development) doesn't have to be that strict at all. But since I'm learning, I'd like to be disciplined.

I appreciate your enlightenment. And any comment on your own method of agitation will be more than welcome.

Best Regards,
Tony
 
The most important thing with agitation is to find a method that works and to be consistent, making changes only to achieve or pursue desired results.

1. I have a timer with a sweeping hand. I set it 15 seconds long, start it running, and pour in the developer at the start time.

2. When the second hand hits the 6 or or the 12 (30 second and 60 second mark), agitate for five seconds.

3. Initial agitation for 30 seconds—you want to get your developer in as fast as possible, preferably less than five seconds with practice, and start agitating. Rap the tank on your hand or sink to dislodge bubbles. Most uneven development problems occur during this time, usually due to insufficient agitation.

At the end of this initial agitation, let the film rest in the developer according to how you agitate—wait 30 seconds, 60 seconds, or the time interval you choose.

4&5. I invert with a twist two times in 5 seconds.
 
As above for me also Tony, except for 4&5. I do 1 sec inversions at 12 o`clock then 3 o`clock, 6, then 9 o`clock. That is 1 second inverted at each point of the `clock', so the whole inversion process takes about 10 seconds
regards
CW
 
Indeed consistency is key. I start the timer once my solution is in tank, and start pouring out in the last fifteen seconds. Others start timing before they start pouring. Whatever you do, just be sure to do it the same way every time. When you make adjustments to your processing later (as you will do, once you figure it out), if you are consistent with when you start your timer and when you agitate, your adjustments will be made to reflect your individual process.

As far as agitation is concerned, it's hard to write about, and easy to teach in person. One thing that complicates things is that ideally you'll use different amounts of agitation for different films and developers. Remember that as a rude general rule, time controls density and agitation controls contrast. (This isn't the end of the mater, but a reasonable general rule.) For most development, I agitate for the first 30 seconds, then for five or ten seconds during each minute thereafter. For inversion agitation, be firm and fluid with your motions, but not rough. I rotate or twist the tank in my hands as I invert, too.

Just make your best guess, relax, and do each step the same way every time. As you gain experience and want to change factors to improve your processing, remember to change only one element of the routine at a time, so that you know which step does what. Finally, remember to have fun!
 
We agitate for one single reason: to guarantee that film is always in contact with developer that has not exhausted...

Sometimes, people don't want to agitate in a normal way, but less... The reason: the highlights zones on negatives require more amount of developer than the shadows, so if you want to avoid burnt highlights, a simple way to do it is doing less agitation, because this way you develop highlights less while the developer on the shadows continue developing for longer than the already exhausted developer on the highlights. This way you reduce high contrast.

About your questions: those differences imply minimal changes... No big difference if you start 30 seconds before or after anything, and no big difference either if you skip inversions once or twice...

When you must pay a lot of attention is when you print: your print must look perfect when the borders of your negative (transparent base) reach black on your print. I mean you should print your image only when your borders reach pure black on paper, and only then you can be sure if your exposure gave you enough shadow detail, and if your development gave you the precise contrast to make only scene's whites white, and not just gray or more things than just the scene's whites white...

Just agitate the same way always and you'll forget about it and concentrate on what's important: development time to control contrast.

You can make it any way you want, and it will work if you remain doing it the same way.

For example, no matter if I'm developing low contrast scenes or high contrast scenes, I agitate for 30 seconds first: a few gentle inversions... Apart from that, whenever I agitate, I do three gentle inversions... If the roll is a sunny one, I agitate at the start of every third minute, and if it's an overcast roll, I agitate at the beginning of every minute.

Cheers,

Juan
 
Thank for the replies everyone.

So in order to reduce the contrast, one should reduce the agitation, but what would be the limit to have lowest contrast possible negatives, but without "the most uneven development problems"?

"time controls density and agitation controls contrast." I'm afraid I don't quite understand the density. I thought longer time would give more contrasty negatives as well..

Is the 30s initial agitation a must? I saw a video on youtube where the guy passed it completely. All he did was 5 inversions every 30s..

Btw, is there any difference between 2 inversions every 30s and 4 inversions every minute?

Juan, wouldn't the film be always in contact with the developer? Unless you use a two reel tank, load the film to the top reel, pour only half bottle of developer? (So when not agitating, the film is not in the developer)
 
No. Don't think of agitation as THE way to reduce contrast... You reduce contrast in a 90% reducing development time... Apart from that, you can agitate less if you fear your highlights could be burnt, but it's development time what counts the most, not agitation.

You can agitate at the beginning whatever you want: 5 seconds, 10, 15, 20, 30, 60, but do the same every time. More agitation generates more grain.

Not a big difference between 2 inversions every 30 seconds and 4 every minute because in both of them you'll have fresh developer all the time both on shadows and highlights... Maybe a little more grain, but nothing important.

The film is always in contact with your developer but: if you pour it and leave it still for several minutes, the developer that's touching the highlights zones in your image will get exhausted soon, while the developer acting on the shadows will still have developing power because the shadows require less developer than the highlights... Developer will be in contact, but in some places it will be dead before than in other places: we're talking just about molecules of it reacting with the silver on the negative, so with a couple of gentle inversions, all film will receive fresh developer again.

Ask whatever you want...

Cheers,

Juan
 
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Well, almost. First of all, you do need to always fill your tank completely with solution, or you risk poor development. Juan said that the whole point of agitation is to ensure you always have fresh, active developer in contact with your film- and this is indeed a big part of it- but it's not quite the whole story.

The key to understanding and controlling monochrome imaging is understanding the difference between density and contrast, and learning to control each aspect separately. When I said "time controls density, agitation controls contrast", and that this is a gross or rude general rule, I should have said that when starting out it is certainly more important to concentrate on getting your time right, as this will account for much of getting correct development. However, since you (the OP) asked specifically about agitation, I will tell you that adjusting your agitation correctlly will allow you to adjust your negative contrast- but this is tricky and subtle, compared to adjusting your time for overall density.

Think of printing: we adjust the time to get the density of the print right, and we adjust the filter or paper grade to get the contrast right. Making negatives is no different, in that you want to get both qualities right for the best results. Of course, since you are going to translate the negative into a positive and you can adjust the contrast in that step, many folks don't worry too much about negative contrast- and generally this is fine. Overall density of the negative, achieved by getting your processing time right, is the main thing, and will get you a negative you can translate into a good positive. But learning to get your negative contrast right will make your job easier- and while it's a more subtle part of film processing, it's worth paying attention to.

This is all further complicated by the fact that increasing your time will tend to add density in areas which have been exposed to more light- your highlights- faster than it will add density to your shadow areas. This is indeed controlling contrast, to a degree; but more time will ultimately add density to your shadows, too- so at a certain point you are just over developing. This is generally the point where adjusting your agitation will tweak your contrast more effectively.

As a beginner, I'd suggest you just establish your basic agitation, and concentrate on getting your processing time right. Start with agitating for the first 30 seconds, and five to ten seconds per minute therafter (yes, some folks prefer a few seconds every thirty seconds, as you mention, and you can indeed do it that way. Just pick one way to do it, and stick with it.) Once you get comfortable with the process, and begin to tweak your times to nail down your overall density, you can then start to play with increasing or decreasing your agitation to adjust your relative density of highlight and shadow areas- or contrast. Just remember to be consistent with what you do, and to have fun.
 
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As others have said, it doesn't matter whether you start the timer as you start to pour in the dev, or when it's all in, as long as you're consistent. I start it when I start to pour in the dev, because when the tank is full, I'm busy: I bang it twice on the table to dislodge air bubbles, then constant agitation for the remainder of the first 30 sec. I start to pour out 15 seconds before the end of my intended dev time: the film will still be wet with dev, so development continues.

Whether you go for 5 seconds in every 30 (agitate from 30-35, then 0-5) or 10 per minute (0 to 10) is not really important, as long as you are consistent.

The effect of agitation on contrast is often grossly exaggerated: the difference between 10 sec/minute and constant agitation equates to about 10% or at most 15% in development time, and unless you are going for 'compensating' development in a weak developer (allowing the dev in the highlights to exhaust) or marked edge effects (boundaries between light and dark areas, achieved the same way as 'compensating' development) your exact agitation regime is completely unimportant as long as it is consistent. You will get a tiny bit more true speed with more agitation, but it's pretty tiny.

Compensation and edge effects depend on weak (highly dilute) developers. With normal strength developers you can compensate perfectly for increased agitation by decreasing dev time, and for decreased agitation by increasing dev time. There will be NO noticeable effect on contrast. This is not just my view, based on experience and using a densitometer to check densities: Ilford research says the same thing.

DO NOT overfill the tank. You need enough dev to cover the film, and no more. Not only are you wasting developer: agitation will be less efficient, because the air space facilitates movement of the developer.

You need very little developer to develop the film: most of it is there to wet the film quickly and evenly. The only common exception, where you need a minimum volume per film, is Kodak Xtol.

To increase both density and contrast (the two are not really separable in development terms): develop for longer; use warmer or stronger (less dilute) developer; or agitate more.

To decrease: develop for less time; use cooler or more dilute developer; agitate less.

Of course, more exposure = more density too.

There is a lot of information about all this on http://www.rogerandfrances.com/subscription/ps neg development 1.html but as Juan said, it's easy to get paranoid and look for more precision than really exists or can exist.

Cheers,

R.
 
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As Roger says, consistency is so important. Here are some tips to help you achieve that:

  • Agitate not only the same number of times, but in the same way.
  • Use either developer at room temperature for stability or use a water bath. While trivial with small changes in temp it can become important, say, if your room is 25 degs C, your dev at 20 degs C and a 15 min dev time. I prefer to work at room temperature always.
  • I generally agitate every minute. This means you are not spending your whole time rapping the tank to remove air bubbles and picking up a and putting down the tank.
  • Although Roger says never to fill the tank completely, most tanks have space in the top for air to circulate. While I normally use on the min developer required, with Xtol or Ilfosol I generally fill the tank to its max rated capacity (not to the lid of course!). This cuts down on frothing and associated bubbles.
  • Leave teh thermometer in the dev long enough to truly settle to a reading. You'll be amazed how the reading can slowly creep.
  • Make notes and keep them safe. Make notes on the conditions and camera the film was shot under. Not all cameras meter the same and so you may need to adjust your speed rating for the same film from camera to camera. You will also learn to adjust for contrast conditions.
Have fun and remember: bad negs make you a better printer so its not a total loss when you have a thin or dense neg!
 
Thanks again for the valuable comments.

The relation between the density and contrast is confusing. In the digital world, I think they are the exposition and contrast, which is much easiler to understand. You can boost the exposition without changing the contrast. (Both shadows and highlights get brighter.) It is not the case when you develop the film 5 minutes longer than the recommended time.

What would happen to the insufficiency of agitation? (for example, without agitation at all) And to the insufficiency of development (for example, 30% of time less). I think the contrast is not the only thing to be changed.

I still have many questions but I've decided to try to achieve consistent results first then ask them in the future.

The last thing, soon I'm going to develop a roll of Neopan 1600 at 1600 in Microphen. The developing time is only 3 and a half minutes, which is unusually short for me. Any idea on the agitation? The film is already very contrasty.
 
Yes: more exposure = more (negative) density BUT more development also = more density + more contrast.

Inadeqate agitation = uneven development with 'streamers' of varying density

Inadequate development = thin, low-contrast neg

Over-development = more density + higher contrast.

Neopan 1600 is not a good flm with which to practice, as it is about ISO 500-650 but is designed for 'pushing' (i.e. for overdeveopment to get more density). Some films 'push' much more gracefully than others, but for maximum control and best tonality it is best to use a film at close to (often below) its true ISO speed. For an explanation of true ISO speeds, see http://www.rogerandfrances.com/subscription/ps iso speeds.html.

Neopan 1600 emulsion is loaded with development accelerators, which explains the very short dev time. Anything under 5 minutes is generally reckoned to be risky (uneven development). Try diluting the developer and using a longer dev time (you ca find recommendations on the web). Dilute deveoper can only be used once as it soon oxidizes.

Cheers,

R.
 
There have been some excellent comments so far, and I am just going to make one point: When agitating, you are attempting to mix the developer. If you are using reels that slide inside the tank, this will effectively mix the developer as you invert. However, having an air pocket will improve the mixing while simultaneously increasing oxidation of the developer. If you have an air pocket, you should really ensure that you are twisting the tank so that the liquid contact is even.

This is a bigger issue when doing 4x5 developing in a daylight / inversion tank. The film holder is stationary, so the only mixing aid is the air pocket. I do not know if plastic roll film tanks have sliding reels, but this may be true for those tanks as well.
 
The relationship between density and contrast with negatives is much the same as the relationship between exposure and contrast you mention in the digital realm. The terms have been changed, but they basically refer to the same thing- the intensity of the image overall. If you hold a negative up to the light and look through it, you will see why what is called exposure with a digital file is called density with a negative. A negative that has been properly processed will be denser, or have more dark areas and more silver overall than a negative that has been under-developed. One that has been over-developed will have too much silver, and look too dark- and highlight areas will be completely black, with no detail.

Since the exposure is made in camera with light and the negative is processed chemically, it is more accurate to call the result in the film density- but it is the result of the exposure in combination with the chemical processing. With a digital file, we simply refer to this as exposure- but really it's about the correct amount of light and the correct processing of the image, whether with chemicals or software.

Again, since this can't be overstated, don't worry too much about your processing- just be very consistent with what you do. Start the timer at the same point in the process, establish your simple agitation routine, keep enough solution in the tank to completely cover your film, keep your temperature consistent, and don't worry. After you've done a dozen rolls and seen the results, you'll be fairly comfortable with the process. After you've done many more, you'll begin to see how adjusting your times, your agitation, and other aspects of the process will affect the outcome.

Finally, I'll agree with Roger (as I do about most things photographic- he's incredibly knowledgeable) that Fuji Neopan 1600 isn't the best film to begin with. As he says, this film is really about 500-650 speed normally. If you've shot it at 1600, this is roughly a one and half stop push. Microphen is a great push developer, but I'd recommend lower speed film and regular developer to start out with. I'd suggest you get a 100, 200, or 400 speed film and try shooting it at box speed or a little slower, and process it normally in D76, ID-11 or another "regular" developer first just to get good results and understand what you are doing. Push processing fast films is a little harder to get good consistent results, so it's not a great place to start. Again- good luck, and have fun!
 
Roger's right: you don't need to fill the whole tank. I've developed with the same 2 roll tank for 20 years developing one single roll and filling the half of it only, and I never had any problem. It's exaggerated agitation what can cause problems. Prudent agitation is always enough.

Cheers,

Juan
 
ulrich.von.lich said:
Thanks again for the valuable comments.

The relation between the density and contrast is confusing.
Click to expand...

Forget about density... We call density any silver on negative. Then, highlights have more density because of having more silver.

Contrast is the important concept. And you will experiment with contrast by developing for longer or shorter times.

You'll see the changes clearly in wet printing. You'll get easily lost if you scan. Scanning you can make and post process files to make them look fine, but as even the scanning is a post process, you can't be sure if your negatives could be better.

Cheers,

Juan
 
Agree with what others said. Adding be consistent so results are always the same.

My procedure is if I have a tank like the patterson that I fill thru the lid, I time the pour in and start the clock perhaps 10 sec early, ie second hand on 10, start clock and begin pout, by zero I begin agitation.

Stainless tanks are best used if you drop the loaded filme reel into a prefilled tank, count and begin agitation cycle. In that case, I set the second hand to 5, start the clock and by zero I am ready to drop the film. Hold the cap with left next to the tank so you can find both in the dark. Start clock with right and drop in reel. Either method works.

Be consistent as exact actual time does not matter. What is important is you taylored the time to the enlarger/paper/scanner and it comes out the same for that application.
 
Juan- I think you and I are using the the terms density and contrast in opposite ways. When you say forget about density, and then go on to describe what you call contrast, you have described what I'd call density. I only bring this up to clarify both our posts for the OP.

Personally, I think CONTRAST- what I would call contrast- isn't as important in negatives as correct density throughout. Correct contrast in the final image will be a result of proper printing, and will be easier to do with a slightly flatter contrast negative, which shows reasonable density- or amount of silver- in both highlights and shadow areas. That is, highlights that are not too dark, or blocked up, and shadow areas that are not too thin on the negative. Correct density throughout the negative, in highlights and shadows alike makes it easier to obtain all the detail you want- or don't want- in these areas in the final print.

However you describe it, I think ultimately we are saying the same thing, but choosing different words to impart information, and perhaps causing confusion. Anyway, I hope this clarifies things.

As for filling a tank only half-way when processing only one roll, I've never heard of anyone doing this and getting consistently even results using inversion agitation. But if it works for you, great. I would still suggest filling the tank to a beginner. When I say filling the tank, I do not mean so ALL THE WAY, so that there isn't any air at all in the tank. Of course there needs to be some room for the chemistry to move, i.e. a bit of air in the tank- but I thought this would have been obvious. I guess not.
 
When we talk about density, we must talk about just a point in the frame.
When we talk about contrast, we talk about the different densities in the frame.

Instead of saying "time controls density and agitation controls contrast", we should say "exposition controls shadow detail, and development time controls contrast."

Cheers,

Juan
 
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