Dark Band in Negative - Uneven Development?

[m_k31]

<p>tried some moonlight long exposure stuff at the beach and developed the film at home. (turns out the exposure wasn't nearly for long enough but that's not the issue.) after processing the film, out of which only a couple of frames turned out, i see a long, dark band than runs the length of film down the middle, from end to end. (photo attached.) not only in the frames themselves, the band is on the ends of the film roll and between frames. my initial thought was that since my exposures were way too short, and aperture small, this was the only part of the film that light hit and started to expose. but that doesn't explain why this band is at both ends of the film roll.<br /><br />further confounding, i developed three rolls in the tank at the same time and two of them have this band and one doesn't. the other roll that does have the band down the middle (also in the photo but less pronounced) was taken with a holga camera weeks ago so it's totally different. the third roll was of normal, daytime exposures and it is completely fine. the fact that 2 of the 3 rolls from two separate cameras has this band in the exact same spot on the film alarms me. could this possibly be a processing issue? or something related to underexposure? i can't figure out how it could be a processing error since the third film process in the same tank at the same time is fine. ever seen anything like this? i'm stumped but i'd like to figure it out so it doesn't happen to something important.</p>

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[ed_lusthoff]

<p>does the band have a tint to it? I had this problem with 35mm and it turned out to be the fixer was a little weak. This also happened last night developing some 4x5 although it did not leave a line the whole negative had a slight pinkish tint to it. (Tmax film) Refixed in some new fixer and it took care of it.</p>

[Alan Marcus]

<p>Chemical development takes place by first infusion of the chemical into the structure of the emulsion. Once the fluid has soaked in it goes to work. As it works, byproducts are generated. These byproducts retard further chemical action so they must be flushed out to allow fresh chemicals to enter and go to work. We are taking about agnation. Recommend is continuous agitation for the first 30 seconds followed by 5 seconds every 30 seconds.</p>

<p>Additionally, when film is spooled on a reel there is always the possibility that the spiral is not correct i.e. film is allowed to touch or approaches the adjacent wind too closely preventing free fluid circulation. Also, if the fixer is substandard it is necessary to extend the time in the fixer.<br>

<br /> It’s a good idea to test your fixer. Have at hand a sacrificial roll of film. Cut it into strips and plop one, undeveloped strip into the fix. This test is to be performed in ordinary room light. Observe the strip; it changes from opaque to clear. Time this reaction than double the time for the fix time you will use.</p>

<p>The seeming spoiled film with the strip down the middle needs re-fixing followed a wash and or treatment with a hypo neutralizer and then a wash.</p>

[john_a5]

<p>You develop 3 rolls in one tank--where in the stack was the one without the line? If it was in the middle and you invert the tank between agitations (alternate the end that is up), it may be your fluid levels not completely covering the film at the top of the tank.</p>

<p>A dark line would generally mean a light leak or light hitting the film when you are spooling it, however, sometimes pressure can affect how film develops out. Do you put a tight rubber band down the middle of your exposed film? I had a pressure roller in one camera create thin lines--they were actually dark on the print/scan, so light on the neg film itself. </p>

<p>If it is a dark line that wont disappear with a refix and you know you had enough liquid in your processing tanks to cover the film, I would look for a light source--point source--near where you load your film into the reels. If it was all out of one camera, I would look for a leak in the camera, but out of two different cameras and nearly identical, light is somehow striking the film during loading or processing--I got some weird solarization at a lab that used dip and dunk, a pinhole in one of their light traps hit the film as it raised in out and of the processing tanks. You might have a pinhole leak at a vent or somewhere else in your room that is hitting the film while you spool it (of course, being so exact would mean very precise positioning of the spools while doing this.)</p>

[JDMvW]

<p>Another vote for possible insufficient agitation, perhaps with a low level of one of the liquids.</p>

[James G. Dainis]

It looks like you have a gray band about 1/4 inch wide running from top to bottom in the middle of that film as it hangs. Is that what you are talking about? I have no idea except perhaps for that rubber band pressure idea.

[bgelfand]

<p>It could be processing, or it could be the camera.</p>

<p>But one possibility has not been discussed. How was the film stored and handled before exposure and processing? Could it have been exposed to some form of radiation? Or were all the rolls stored and transported together?</p>

<p>Then there is the fact this these were LONG exposures. Could there have been a stronger linear lisght source in the frame that the film "saw" but you did not?</p>

[m_k31]

<p>thanks for the responses.</p>

<p>yep, that's it - the gray band about 1/4 wide down the middle of the film from end to end. you can see it in the shadow areas of the roll on the left, too, but less pronounced than the roll on the right.</p>

<p>out of the 3 rolls, the one without the band was on the top, the two with the band on the middle and bottom.</p>

<p>my liquid levels definitely submerge all rolls in the tank. i do agitate for the first 30 seconds and every 10 seconds for each minute following. i don't vigorously agitate and don't fully invert the tank. i tend to gently tilt the tank about 90 degrees each direction but not a full 180 degrees. i've had trouble with a full 180 degree inversion in the past - the bottom part of the roll at the bottom of the tank received uneven development due to the liquid filling the empty space at the top of the tank when turned upside down, leaving the bottom roll partially uncovered with liquid for part of the agitation cycle.</p>

<p>i tried further fixing, but as John A predicted, refixing didn't help. it definitely looks like a light-leak issue but i can't imagine where it would be coming from. it is highly unlikely to impossible for me to spool two rolls of film in precisely the same position allowing a light leak to run the length of the roll in a straight line. the tank is new and haven't had any trouble with many other sessions. processed some 35mm rolls tonight with no issue.</p>

<p>improper spooling is a top contender for the culprit but the stripe is so uniform and in the same spot on both rolls - that makes me doubt that it could be the problem, too.</p>

<p>still stumped.</p>

 

[m_k31]

<p>good call, brooks. the two rolls with the band in the middle are older rolls that may have done some oversees traveling before being opened and exposed. i'm not exactly sure how long i've had these rolls. i traveled internationally a couple of months ago and these could be leftover from that batch. again, 400 ISO tmax. but the one good roll from this developing session was definitely a brand new box.</p>

<p>xray damage just might be the problem.</p>

[gary_gumanow]

<p>I've seen this dark band on my film, 120 also, but it was because I checked my bag with my film in it through baggage on a flight. The scanner when you check your bag will fog your film. Did you check this film through in your checked bag, or do you hand carry onto the plane?</p>

[m_k31]

<p>yep, it was absentmindedly left in checked bagged on an international flight. so i am sure that is the problem. i am just lucky all of my film wasn't in the same bag as i had some irreplaceable shots from places i might never travel again. i now request a hand check of all my film with no exceptions, no matter the speed, exposed or unexposed, rather than have them go through any xray, even for carry on. so far i've encountered no resistance from airport security but i've only flown domestic since then. thanks for the feedback.</p>