how to prevent banding on developed film

Discussion in 'Film and Processing' started by lieven_van_meulder|1, Oct 19, 2018.

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  1. hi,
    I developed my first film with Rodinal. The images on the film appeared, but with strange vertical banding.
    I read somewhere is possible because of no constant agitation of the Fixer? I used ilford Rapid Fixer.
    But agitated not constantly for 1 minute..
    Here you can see the film.
    The vertical banding appear on each photo more or less.

    View attachment DSCF5967.JPG
     
  2. Improper fixing can also be a cause. I have had it happen when reusing fixers. Since the film is not looking good anyway try re-fixing the film and see if the banding goes away. Despite it being possible I have never caused banding by any agitation method.
     
  3. Hi mjferron,

    What you mean by improper fixing? I did more then 60 seconds of fixing and little bit of agitation in beginning.
    Should i agitate more or less.. Or is the banding the result of even agitation. Too much in the same direction?

    Also tried to do the fixing again in hope of banding going away. But there was only a slight improvement.
    Maybe 20 percent improved...
     
    Last edited: Oct 19, 2018
  4. If there is ANY visible change after refixing, this pretty much means that your first fixing was not adequate. The fixing step should completely remove the undeveloped silver halide, with a safety factor of about 2X. So the fact that you saw a significant change in the film from refixing suggests that you are doing something wrong.

    There can be some slight exceptions to this. For example, Kodak T-max films might have a slight pinkish tinge after normal fixing, that usually comes out in the wash step. But I'm guessing that going back into fixer longer might also remove it.

    I can't understand, from what you wrote, how long you actually fixed your film. Did you do it according to Ilford instructions? (Their data sheet for Rapid Fix suggests 2-5 minutes for "general purpose film" with dilution of 1+4.)

    I would suggest that you try fixing a bit of 35mm film leader in the light just so you can see what happens during fixing. Fwiw your film problem - streaking coordinated with the sprocket holes on one side of the film doesn't look, to me, like something the fixer would do.
     
  5. I see the streaks on the film, but where are the images? Are you sure you developed it long enough? Because you sure as heck didn't fix it for the right time.

    Were there no instructions packed with the chemicals?

    Fix for at least 5 minutes. You can't easily over-fix a film, but you can under-fix and impair its keeping qualities. 1 minute is far too short a fixing time.

    Anyway, those marks are called 'streamers'. You'll notice they line up with the sprocket holes of the film and are caused by insufficient agitation.

    If you're not using an inversion tank, then get one. The 'twiddle stick' method is very unreliable.

    Agitation should be two inversions per minute, keeping the tank upside down for about 5 seconds each time. Overfilling the tank and leaving no airspace also impedes agitation. You should use the recommended quantity of developer for the tank and no more.
     
  6. Someone correct me if I am wrong, but I thought "streamers", if that is what these are, were caused by too much agitation - the developer rushing through the holes and over-developing the adjacent film. This happened to me once when I was first learning film developing way back.
     
    lieven_van_meulder|1 likes this.
  7. Streamers can be caused by too much or too little agitation. The more likely cause is too little.

    Technically, it can only be caused by insufficient mixing of used and fresh developer, which would be classed as insufficient agitation in my book. Just madly shaking a tank about doesn't necessarily mean that the developer gets properly homogenised.

    Try filling a bottle right to the top and then carefully add a drop of dye or ink. Stopper the bottle and leave no air space; then try to mix the ink with the clear water. How easy is it for the liquids to mix with no space in the bottle?
     

  8. Yes fix longer. 3-4 minutes for traditional films and 5-6 for tabular films like TMax/Delta
     
  9. How was the agitation done for each step (fixer, developer, etc.)?
     
  10. Review this, paying attention to the agitation section.
     
    lieven_van_meulder|1 likes this.
  11. If you look at the top edge of the film, you will see that it is fogged. This fogging likely happened when you were loading the film onto the developing reel. It also could be fogged from X-ray exposure at the airport or the camera back has faulty seals around the seams. Anyway, this film was fogged. The film was rolled up when fogged. The sprocket holes, being void of film allowed the light to fog the rolled up film. The sprocket holes of the top layer of roll of film of film do not exactly overlay the sprocket holes of the film beneath it. Thus you see some fogging between the sprocket holes. This defect has nothing to do with agitation or time in any of the solutions of the process.

    We must always guard against the film being fogged. Most times we see this when the dark room is not truly dark. It takes fully an hour for the human eye to dark adapt. If we are in a lights out situation for just a few minutes, we can’t be sure of the light tightness of our dark room.
     
    Last edited: Oct 21, 2018
  12. Fogged similar to this one from an expired film in a Minolta 7s I bought so I just finished it off but I the back had already been opened once or twice

    Fogged 1a.jpg
     
    Last edited: Oct 21, 2018
    lieven_van_meulder|1 likes this.
  13. Good call by Alan.

    I wonder if the mechanism of the fogging was light piping through the film base, being disrupted by the open sprockets. I don't recall having seen pure edge-fogged 35mm film before - it's almost always protected by the flange of a spool - so can't say for sure. Perhaps the film came from a flange-free bulk roll where the can lid had been removed in the light.

    Nonetheless all of the fixing advice still holds.
     
    lieven_van_meulder|1 likes this.
  14. The 'rolling' action in that video is totally unnecessary. Just turn the tank smartly upside down and wait a few seconds for air to bubble through the spiral, then turn the tank upright again. Making sure to hold the tank lid firmly in place!

    (Personally, I wrap a strip of vinyl tape around my stainless-steel tank lid for insurance.)

    Also, the tapping of the tank on the bench is far too gentle. The purpose is to dislodge any air 'bells' adhering to the film, and a gentle little tap like that shown will do absolutely nothing. Put a doubled-up towel on the worktop and bang the tank bottom down on it quite hard.

    The tank needs this 'banging' as soon as it's filled, BTW. It should be the first thing you do after the cap has been fitted after filling with developer.

    Who teaches these people the nonsense they video in order to spread such poor technique?
     
  15. Thanks for the tips.
    I used that video for somewhat of a guide and got pretty good results.
    The “rolling” would seem likely to well distribute the liquid.
     
    lieven_van_meulder|1 likes this.
  16. Hi, I sort of disagree; my guess is that, with the very slow rotation as seen in the video, the majority of the agitation will be around the outer parts of the spool.

    I see it the same way as rodeo_joe; the bubble making its way to the other end of the tank does the most important agitation. A slow inversion will let the bubble come up the side of the tank, avoiding the central area. A brisk inversion will prevent this. Anyone who has mixed solutions in a volumetric flask by inversion will understand what I mean.

    Does it really matter? I dunno; never specifically tested the results.
     
    lieven_van_meulder|1 likes this.
  17. Hi Moving on,
    Thanks a lot. I learned a lot from that movie.


    Hi Alan,

    Suddenly i remember have tried to open the camera by accident. I underestimated it because i only opened it maybe for 1 millimetre. Now i think i might have caused some fogging as you said...

    I will try develop one more film and come back with what i find.
     
  18. Streaking caused by aggressive agitation across sprocket holes are one of the most common problems with hand processed black and white. I can also induce the problem via putting a nitrogen burst pipe too close to film reels. I also used to work with these 4x5 racks that had perforated holes about 1/4 inch apart for developer flow, and they produced a similiar problem as 35mm sprocket holes.

    The issue is also strongly dependant on films you use. Kodak Panatomic -X and Plus-X were the most sensitive while the newer Tmax films are fairly resilient to it. First time I used those 4x5 racks with a customers plus-X sheet film the streaks were so bad he had to re-shoot. Made sure I agitated at 1/4 the speed next time. There's a reason most commercial labs switched to tube development / Wing Lynch processors for B&W because the rotary action of development never caused developer to traverse sprocket holes and hence you got really smooth density uniformity across 35mm.

    The way my zone system college instructors taught is the way I suggest doing it; as you invert the developer tank rotate it at least one turn. This breaks up the vortex pattern to a great extent although if you're using a film prone to the problem it will be tough to eliminate completely. We shot neutral grey cards and were actually graded on how uniform our frames were in college, which was good technique to learn in the long run. The fact you have not experienced the problem tells me you've been lucky enough to avoid those films and developers prone to it. Just quickly inverting a development tank is asking for trouble.

    If anything is dumb it's the use of acetic acid acid / stop bath / vinegar. Only a brief rinse of water between developer / fix is required to normalize pH.
     

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