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Adjusting fim development - by time or by developer concentration?

jwalton

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Hi, For a while I've been using DDX on my FP4, but, finding that Ilford's times and concentrations massively overcooked my negs, I reduced each by 10 to 15%. This gave me negs that I was satisfied with.

Now I'm sure that I'm not alone in thinking that DDX is mighty expensive (following Ilford's guidelines I would be looking at around £1 per roll of 120 film), so I've just started on my first box of ID11 and used it 1:1 for 11 minutes, as prescribed. Result: very nice, but again very overcooked.

So, I know that I need to adjust my development down.

My question then is really a general one - I want to understand the relationship of the concentration of developer to the final quality of the developed neg. To put it another way if 10 seconds at 1:1 gave you the same neg. density as, say, 15 seconds at 1:2 (just for the sake of argument) would we see the same quality of neg, and, if not, what would the likely differences be?

Many thanks for your musings
 
Time would be my first adjustment. If the mix ratio is tampered with you run the risk of a lack of developer in the solution. You want there to be sufficient chemistry to react with the film. Research that first before changing your mixing ratio.
 
Changing development time is the most common way of manipulating your film's contrast, but you can do it with dilution at fixed times as well. There just isn't nearly as much published information on doing this, so you will have to experiment (and then let us know ).

One guy figured out exactly how HC-110 dilutions affect contrast at a fixed development time. I read about it here on A.P.U.G. some time ago. I don't remember the guy's name, and I have never used his technique, but I remember the chart showing contrast with dilution at 1:30, 1:40, 1:50, etc., and results similar to changing development time. I don't think there is any reason that similar results could not be obtained with any b/w developer.

I am curious to try the technique with E-6 first developer more than with b/w film, personally. Possibly C-41 too, though from what I have read, it seems like a more sensitive process in regards to tweaking development.

With a fixed development time, I doubt you'd see much difference in the qualities of the images at different dilutions unless you got to extreme dilutions in which the developer simply runs out of gas before it can develop the film. In these cases, you'd likely have the most exposed areas suck up all the activity from the developer before it fully develops the rest of the film.

OTOH, when using different dilutions at different times to achieve the same contrast on two rolls of film, there are differences. For example, I notice more grain when going from HC-110 at 1:31 to 1:63 and developing for the same contrast.
 
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Time is the easiest route to go. If the developer you are using is too expensive, use a different one. ID-11 / D76 are inexpensive developers that will serve you well.

In a much simplified manner - exposure determines shadow detail, and development determines highlights. Work on getting your shadow details correct by varying exposure. When you have that aspect of the process under control, change development time until you have negatives that look good from deepest shadow to the most intense highlights.

- Thomas
 
Changing dilution ratios can do more than just change development times and/or affect the appearance of the grain structure. I've seen charts done by Kodak, presumably from data they generated in their labs, showing that while you can obtain the same contrast index (or at least darned close to it), the shape of the curve is changed slightly.

See pages 9 and 10 of this document, pages 14 thruogh 18 of this document, pages 17 through 15 here, and page 8 on this one.
 
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I noticed no mention of adjustments for temperature. In my personal adventures I found that the proper time adjustment for the developer's temperature makes a world of difference.
 
Hallo,
For what it is worth I got into a terrible muddle earlier this year with dev times/dilutions and ISO ratings.
After some advce here I bit the bullet and went back to real basics of starting with the box peed of the film, quoted dev times and then using these as a base point could establish my preferred ISO and preferred dev time for how I like to print. This combined with the d-max print test has done a lot for the understanding of how to get to where I want to be.
It is slightly tedious, without taking notes at all steps is fairly pointless but the whole process can be useful.
I used to dilute ID11 at 1:1 (or 1+1, depending if the dilution thread has been read ) but use stock until I have the time to do the tests on diluted dev - it is my understanding that dilute dev will alter the curve characteristics of a film but a reduced development will compress the curve. A subtle distinction, but might be wrong here.

Embrace the test, or just let it all hang with the wind! Choices, choices, choices!

Sim2.
 
This subject is sufficiently complex to fill a PhD thesis. You will quickly face issues such as 'min required development agent', 'acceptable gradation change', 'highlight starvation' and others. Once you figured it out, don't add an additional roll of film or you have to start all over. I tried this once, and it took me days to get the knot out of my brain.

I suggest to stick to one dilution, covering at least N-2 to N+2, and conduct a proper film test ala Phil Davis, requiring no more than six rolls of film. That's all it takes and is far more efficient than years of trial and error.
 
Thanks for all the replies..

I completely appreciate that the simplest answer is to change time (using the same dilution - oh, and I always use a constant 20 degrees C), but I suppose that I'm after a (relatively) simple executive summary of Ralph's PhD thesis on how dilution affects the neg.

For instance Ilford give these three options for FP4 (at ISO125) souped in ID11: 8.30 in stock, 11 at 1+1, or 20 at 1+3. They say that "best overall quality" is to use stock. All these three dilutions will have "min. required development agent" no doubt. By the way, I think that using stock ID11 makes it about as costly as DDX.

I think that I'm going to have to dust off a few books and start to understand the curves that have been helpfully linked to above but, in the meantime, if anyone has that summary of Ralph's PhD thesis......
 

I'm reminded of an old saying that two years of research can save a whole day at the library.
 
jwalton said:
...All these three dilutions will have "min. required development agent" no doubt. By the way, I think that using stock ID11 makes it about as costly as DDX.
Click to expand...

Maybe, but stock ID-11 like its kissing cousin D-76 can be reused a number of times with adjustments to the development time to compensate for developer exhaustion. It can also be replenished and used repeatedly over a long time; but that only makes sense if you run a lot of film.
 

Doesn't that depend on how much of it is used per roll of film?
 
For ID-11 with,say,FP4+, you could plot the times from the massive development chart versus concentration 100%(1+0) 50%(1+1) and 25%(1+3).
I presume these would give the same density but as dilution is increased there would be an increase in acutance and grain due to lower sulfite content.
 
Ralph
Perhaps we're getting closer to what I'm trying to understand. Clearly, if used more than once, the developing agent would eventually be used up, but used as a one-shot developer one would assume that Ilford are happy that 1+3 gives sufficient development agent.

So I'm back to trying to understand what the difference in quality actually is between stock at one extreme and 1+3 (in this case) at the other extreme. Then I'd like to have a minimal understanding of why these differences happen. In the meantime I've been reading Michael Langford's Basic Photography (1997 edition), Barry Thornton's Edge of Darkness, and John P. Schaefer's Basic Techniques of Photography, though, as I suffer from M.E. (Chronic Fatigue Syndrome) I'm struggling to absorb all of it yet.

Alan - sorry I hadn't seen your post until just now. Thanks, I think that this is the sort of answer I'm looking for. So, using at stock I'd get an overall "smoother" neg? Using at 1+1 is a reasonable compromise between different (not necessarily "better") characteristics?
 

Don't make that assumption, because you still need a sufficient quantity of it.

Let's say you are using a Jobo UniTank holding 240 ml for rotation processing and you are trying to develop the maximum number of 35mm films this tank holds, which is two.

At 1+3 that leaves 60 ml of stock solution to develop two rolls of film. That's not enough, and don't blame Ilford for it. They didn't tell you to go below the minium stock solution per roll, which is, depending on who you ask, at least 75 - 100 ml per roll of film. So, in the example above, I would not go below 1+1.
 
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If you're consistently overdeveloping (with normal times/dilutions according to manufacturer directions), perhaps another factor may be to re-adjust EI rated on your camera. Shoot a couple of test rolls, bracketing the same subject, develop (Normal) in the chemistry of your choice -- the suggestions, above, of D-76/ID-11 are perfect, stock or 1:1 -- and see where the adjustments in exposure need to be made, prior to playing around with various developer dilutions.
 
Ha! I feel that I'm being cleverly toyed with here - and that's no bad thing. You are gently nudging me towards thinking around the subject so that I find the answer myself without being spoonfed. So I thank you for that and hope that you will continue to indulge my slow fumbling towards enlightenment.

It may be no surprise to you that this is my first experience with discussion groups on the web. So far, so interesting, on lots of levels.

Back to the books methinks - any more suggestions? I've already looked to see if I can order Adams' The Negative (and some other titles) from the library.
 
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