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  1. #21
    Bertil's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    Agitation should NOT be vigourous.
    Yes, it should (though not unnecessary violent, off course).
    I will just give some hint of evidence:
    1) My own experience with many years problem with uneven development and a lot of experimentation,
    2) Scientific evidens about what happens at the film surface when the film is moving around in the developer, nicely explained by Gordon Hutchings in his "The Book of Pyro" (p. 20) where he explains the "laminar flow" which is part of the scientific explanation of why many "soft" agitain methods are inadequate,
    3) "Use vigorious agitation at 30 seconds interval" is Kodak's recommended agitation method on the filmpack for T-max 400.

    But as long as you get the negatives you want your method is the best!
    /Bertil

  2. #22

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    Update.

    I started by cleaning the mouth of my bottle of Rodinal. Dried up Rodinal had coated this area. I also cleaned out the small beaker I measure it with. I often don't do this between films but I cleaning right after I mixed the developer with water. I also tapped the tank after the first 30 sec of development as well as before.

    I then used water as stop instead of stop bath. I continued with the agitation time of 10 sec every minute but with far more vigorous agitation. So far all of these problems have resolved.

    This has certainly made me more cautious when developing my film.
    Bachelor of Fine Arts and Bachelor of Arts: Journalism - University of Arkansas 2014

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  3. #23
    baachitraka's Avatar
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    If you have small tank: 300ml water + 6ml Rodinal will be sufficient for 1+50.

    I do not understand why you want to agitate vigorously. Agitate 10 sec(gently) and give a hard tap at the end to dislodge air-bubbles if any.

    I have developed an another roll on Yesterday and it came really well too. Soon, I will post some scans...
    OM-1n: Do I need to own a Leica?
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  4. #24

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    When I use rodinal for any film agitate continuaoly for the first minute then 2 inversions every 30 seconds, as suggested by Agfa, a long time ago, and I get great negatives, there is no need for vigorous agitation with Rodinal, but it is essential that whatever you use to mix the stuff is wel rinsed out after using as Rodinal reacts badly to stale developer'

  5. #25
    Thomas Bertilsson's Avatar
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    Quote Originally Posted by Darkroom317 View Post
    Update.

    I started by cleaning the mouth of my bottle of Rodinal. Dried up Rodinal had coated this area. I also cleaned out the small beaker I measure it with. I often don't do this between films but I cleaning right after I mixed the developer with water. I also tapped the tank after the first 30 sec of development as well as before.

    I then used water as stop instead of stop bath. I continued with the agitation time of 10 sec every minute but with far more vigorous agitation. So far all of these problems have resolved.

    This has certainly made me more cautious when developing my film.
    Good you got it worked out! The pre-rinse, and avoiding the acid stop bath seems to be strong contenders for the problems you've seen.
    For what it's worth, most people saw problems with the Foma 200 film in 120 format, a few reports on the Foma 100, and I can't remember any complaints about the 400.

    About agitation: The purpose of agitation is to bring fresh developer in contact with ALL of the film area in the tank, at the same time. If your agitation is too slow, then you run the risk of uneven developing, and if it's too fast, you could see edges of your negatives more developed than the center of the film.
    A happy medium is best, where you need to make sure of the following:
    1. Do NOT completely fill the tank, because if it's completely full, the developer will not flow inside the tank to properly mix the developer up before you set it to rest again.
    2. Do full inversions, but do it fairly slowly, like one full inversion in about three seconds or so.
    3. Do not shake the tank.
    4. Tap the tank before you set it down to rid with air bubbles trapped on the film surface.

    I had lots of problems with uneven development in 2008, and my actions above solved all of them.

    Good luck!
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  6. #26

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    Skip the stop bath. It`s purpose is to neutralize alkaline developer. Fix does the same thing at some loss to fix capacity. Since I do not use fixer more than one time, I don`t care. Normally I use alkaline fix so why go base, acid, base.

    Always use fresh chemicals. Throw away old stuff. Silver precipitates in used fix and settles on the next film ( that is the black particles on the bottom of the bottle). Those are the white spots on the film.

    Use an eyedropper or transfer pipette to get Rodinal from a bottle so you do not pick up the precipitate from the bottom.

    Use glass bottles you can clean and always use the same chem in the same bottle. Label it.

  7. #27

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    I am pretty much doing what Thomas recommends as far as agitation.

    Thanks to everyone for the suggestions. I am glad I will not need to switch films because I really loves the tones of the 100 and 400 films. I have yet to try the 200. I think I shot one roll of it back in 2010, when I first tried these films. I will likely use it when I have a use for it.
    Bachelor of Fine Arts and Bachelor of Arts: Journalism - University of Arkansas 2014

    Canon A-1, Canon AE-1, Canon Canonet GIII 17, Argus 21, Rolleicord Va, Mamiya RB67, Voigtländer Bessa

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  8. #28
    Bertil's Avatar
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    [QUOTE=Thomas Bertilsson;1364896]

    About agitation: The purpose of agitation is to bring fresh developer in contact with ALL of the film area in the tank, at the same time. If your agitation is too slow, then you run the risk of uneven developing, and if it's too fast, you could see edges of your negatives more developed than the center of the film.

    Well, Thomas, agitation during development seems to require a thread of its own! You say: "if it's too fast, you could see edges of your negatives more developed than the center of the film". And I agree, overdeveloped edges of the film (at least 35mm and 120 film i small tanks with reels) is a common problem. The question is: what's the correct explanation for this overdevelopment? One explanation could be that the developing process speeds up during fast agitation. I doubt that's the full/best explanation. Suppose the total developing time is something like 5-10 minutes, agitation with 30 sec interval, or less or even with continious agitaition; now suppose the time you agitiate is 5-15 seconds, not very much development could be expected during this short period relative to the total development time, even with continious agitation. I think a better, or complementary explanation, is that the agitiation, even if fast, is NOT SUFFICIENT to fullfill your correct condition that agitation should "bring fresh developer in contact with ALL of the film area in the tank, at the same time" -- a problem is, off course, how to estimete this "same time", but suppose 5-15 seconds is enough if total development time is 5-10 minutes (or more). If you agitate fast (like Kodak once recommended 5 inversions in 5 seconds!), sure, there will be a lot of turbulent movements around the reel which hold the edges of the film. The result is that fresh development enter the emulsion (and used products that counter act development is washed out from the emulsion) AT THE EDGES, BUT NOT necessarily at the whole film surface – and this "insufficient exchange of chemicals" could happen both with soft and fast agitation, i.e. IF IT'S NOT sufficient to substitute fresh developer for used products evenly over the whole film surface.

    The problem thus seems to be: how to achieve sufficient substitution of frech developer over the whole film surface during the agitaion period?

    In my experience the solutioin is not "softness" (if you don't take risks with uneven development, probably due to a mistaken belief of getting too contrasty negatives (try a more diluted developer!), rather the opposite.
    BUT it should be done also following your good advise of not filling up the tank; that's VERY important in my experience (and experiments). I always now use a tank double the size of the reels and developer reasonable covering the reels, such that when the tank is inverted the film is free from developer and then new developer enters the film surface when going back; I agitate not just by inverting the tank, I also rotate, back and forth, up and down, to insure that the exchange of chemicals is sufficient all over the film surface, and without some regular pattern of the developer flow over the film surface. With this method I have even been violent with critical negatives without unevenness! When I have had problems it always seems to be being too "soft" or in combination with too regular movements during agitation.
    This practice, related to the explanation of "insure sufficient exchange of chemicals", seems to work equally good with all sheet films I have tried (4x5, 5x7, 8x10).

    My experience with continious agitation in the JOBO rotating drum (just tried C-41 developing with this equipment) seems to give some support for the "insufficient exchange of chemicals" explanation of unevenness. Developing 120 film with big reels (two 120 film/reel) in a big tank taking 3 reels, the tank is rotating back and forth (up till 10 minutes depending on the temp.). But the fact that the film is moving (even if fast!) in the developer (more or less still standing) is not enough for proper exchange of chemicals; but turbulence around the reel's edges makes a difference, and the result is overdevelopment at the edges by this method. By removing the tank and agitating by inversion as above (each 30 seconds or once a minute), and then back to the rotating movement, the result is good even development – and i think this must be judged quite vigorious agitation.

    But, if the negatives are good, the developing method is good!

    /Bertil

  9. #29
    Thomas Bertilsson's Avatar
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    Bertil,

    I honestly don't know what causes it, but I know I've witnessed it.
    But, I don't really care to find out either. As long as my negs are perfect and easy to print, then I'm a happy photographer.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  10. #30
    Bertil's Avatar
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    Thomas,
    yes, that's enough!
    Have a nice summer!

    /Bertil

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