Trouble with screen and tube

Discussion in 'B&W: Film, Paper, Chemistry' started by bpm32, Oct 5, 2004.

  1. bpm32

    bpm32 Member

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    I've been using cibachrome tubes with 4x5 film. I use a machine to roll the tube, although it's a unidirectional roller, so I have to turn the tube around every minute.

    After some great suggestions on here, I started using fiberglass screen cut just a bit larger than the film, and sandwiching the film and screen together before sliding it in the tube. (emulsion side up, or away from the screen)

    I think this is a great method, but more than occasionally I'll get a grid pattern from the screen left on the backside of the film. This, in turn, translates onto the paper when I'm ready to print the negative.

    Has anyone else run into this? Any suggestions for fixing this? Is it due to using a unidirectional roller, and maybe during the presoaking stage (6 mins) the water isn't being agitated enough to clear the halation layer? I almost feel like the cibachrome tube has such a narrow diameter that the film is rolled so tightly against the screen, the water can't get behind there to clear the layer.

    Thoughts?

    I appreciate any help you can send my way - grid patterns don't add a lot to my photos.

    Thanks!

    Brian
     
  2. bpm32

    bpm32 Member

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    Anyone have any suggestions at all?
     
  3. MikeK

    MikeK Member

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    I use a Jobo Print Drum for processing 5x7 and 8x10 negatives and it works fine. I used to use an old Beseler print drum on a motorized base. Both methods gave good results and no fiber glass screen.

    I suspect the screen is pressing against the film and chemistry is not getting to those areas. You are loading the film with the emulsion side facing toward the center of the tube and the backing facing the wall of the tube - right.

    If you are then the screen marks should disappear in the wash.

    Hope this helps - Mike
     
  4. bpm32

    bpm32 Member

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    Thanks a lot for your reply, Mike!

    I hold the film (Ilford Delta Pro 100) with the notches at the top right. I then place that on the screen and slide it into the tube. With the notches at the top right as I lay it down, that is emulsion side up right? (sometimes my brain goes haywire)

    I wash the film for 20 minutes... but it still won't go away. Should I wash it longer... or use additional methods of washing other than self-emptying tank?
     
  5. MikeK

    MikeK Member

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    I know this can be confusing, but with the notch at the top right hand side the emulsion is facing you.

    Washing for 20 minutes should clear the backing. So, a little more investigation. Are the screen marks clear, ie can you see through them? And a quick test, do they change if you re-fix the film.

    My gut feel says you loaded the film the wrong way round into the tube - but lets keep going

    - Mike
     
  6. gainer

    gainer Subscriber

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    You don't say if you are washing the film in place in the tube or removing it and washing in a tray. You are probably seeing the remains of antihalation backing which is in contact with the screen. A short try wash in weak sulfite solution might remove the grid.
     
  7. bpm32

    bpm32 Member

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    The lines from where the screen was actually in contact with the film is clear. It's the empty spaces between the screen grids that is the value that it should be. To me, it does sound like I put this sheet emulsion side against the screen. But let me say again, just to make sure I have it right...

    I pull the sheet out of the sheet film holder. I feel the notches at the top right (on the short edge of the sheet). I place the sheet on the screen with the notches at the top right of the screen. I then curl then sandwich and slide it into the tube. (In short, I literally pull the sheet straight out of the holder and place it straight onto the screen, never turning it right to left, or flipping it.)

    Am I missing it - or isn't that the way it should go?

    I did try refixing it, but that didn't clear it up.

    I wash the film in a hanger in a tank. If this helps visualize the problem, the negative has those lines only in the middle 1/3 of the negative. If you hold the negative in front of you, the longest edge on the sheet would be vertical, the shortest edge would be horizontal. In that position, the grid appears halfway down the sheet in the horizontal position, or across the shortest distance of the neg.

    When I roll the "sandwich" and slide it into the tube, the neg naturally wants to uncurl. This tendency puts the most pressure against the screen at the point where the grid is showing on the neg now. (does that make any sense??) There are times I've noticed when I go to wash the neg - as water crosses over the negative at that spot, the water will cross over this section differently - you can almost see the grid pattern appear where the water will collect or bead across the neg. Is this shedding any light on the situation?

    Where would a good place be to buy this sulfite solution? I don't want much at all, in case this isn't the fix. :smile:

    Thanks a bunch for your patience with me on this.

    I've got a real mess.
     
  8. MikeK

    MikeK Member

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    The fact that the grid lines are clear means the the film was fixed OK. So hold off on getting the sulfite just yet. No matter how long you soak the film the sulfite bath will not help.

    You do seem to be loading the film in the tank correctly, but it is easy to become disoriented in the dark. What I would do would be to sacrifice two sheets of film. One to practice loading into the tube and the other to take a test shot and run through your process again.

    Mike
     
  9. John Koehrer

    John Koehrer Subscriber

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    Could it possibly be stress marks from the pressure exerted by the film itself within the tank? I think we've probably all seen them on roll film.
    Do the marks appear if you don't use the screen?
     
  10. bpm32

    bpm32 Member

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    Thanks again for everyone's reply so far...

    I've got a few sheets that I either felt like I scratched as I was putting them in, or an unexpected flash of light occurred (lightning bug!) while I was loading the film into the film holder. So I can practice with those. My process is so simple though - I can't see how I'm messing that up. But I'll give it a shot and see if it makes any difference.

    As for the stress marks - I didn't get these lines when I wasn't using the screen. The reason I started using the screen was to cut down (or reduce completely) the number of scratches that I got from sliding the film in and out of the tube. Using this screen, I no longer get any scratches, as long as I'm careful. It's interesting - sometimes I get these grid lines, sometimes I don't. Sometimes they're less noticeable... but on this last negative - they're VERY noticeable!

    It's kinda scared me from developing any more film until I get a better handle on what's causing this. I -really- like this method - the rolling in the tube method - but I obviously can't keep using it if it's going to do this. I know it's the screen, b/c the lines and grid pattern match up perfectly with the screen I'm using. I guess the question comes down to whether or not I'm laying the film onto the screen incorrectly. I figure if I'm loading the film holders correctly (never loaded one wrong so far), then I should be aware enough to load the tube correctly. (Pardon me - I'm thinking outloud now - maybe this would be more appropriate in my journal)

    Maybe I'll look for a different screen. The mesh I've got is very fine. If any of you use this method - what kind of screening are you using? Mine is intended for doors/windows, and it is fiberglass.

    Thanks for letting me vent.

    Brian
     
  11. Jorge

    Jorge Inactive

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    One question, do you wash the screen after use everytime? Even if you do your film washing in the tube, if you dont wash the screen thoroughly, you still get some residue left on the screen. Try cleaning the screen by scrubbing after you do all your development and use it again and see if you get the same pattern. Good luck.
     
  12. bpm32

    bpm32 Member

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    Hi Jorge,

    Thanks for your reply. That's a good question. I "lazily" rinse it off under running water, but I do not scrub them. Perhaps that's the problem?!? I might try cutting new sections of screen (I bought a whole darn roll of the stuff at the hardware store) and see what I end up with.

    I just posted my first journal entry so I could use that to vent and quit wasting everyone's time here with that stuff - and while I was doing that, I had another interesting thought.

    Out of habit, I place a yellow sponge in my sink, then place the screen on top of that. After that goes my exposed negative. It's only on there long enough for me to put the film holder down and pick up the screen and film. My darkroom is light tight. I'm wondering if there isn't just enough light reflecting off the sponge to create this grid? I develop at all different times of day - which means there'd be different amounts of light in there too. That might explain why some negs have more or less of this grid pattern.

    I can't wait to get back in there and run some experiments... hopefully tomorrow.

    Thanks again!

    Brian
     
  13. Landrum

    Landrum Member

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    You are loading your film backwards, in the film holder and into the tank. When the notches are in the upper right hand corner, that means the emulsion is facing down. When you load your film into the holder with the notches in the upper right hand corner the emulsion is facing the septum in the holder not the lens, the way it is supposed to be. The film should be loaded with the notches in the lower right hand corner of the holder, in this manner the emulsion faces the lens and the antihalation backing is against the septum of the holder. The same holds true for loading into the tank. I imagine your images don't look right anyway because you are exposing through the antihalation backing first before it hits the light sensitive emulsion. Images that have been exposed like this have a flairy look to them, not to mention it takes many more times of exposure. If anyone else tells you differently they are absolutely wrong!!! This information comes from someone that has loaded thousands of sheets of film in the advertising photo industry.

    Your images will look much better once you get the film loaded correctly.

    Good luck

    Greg Landrum

    PS.
    There are some odd people that rotates the film so that the notches are in the upper left corner, this means that the notches are at the far end of the holder not the hinge end. The film maintains the same emulsion orientation towards the lens this way, but there is bigger chance of screwing the loading up this way because the notches are not at your finger tips at the end of the procedure.
     
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  15. Landrum

    Landrum Member

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    This is an afterthought from my earlier reply. That is all based on the fact that the film is being loaded by a right handed person. Generally a right handed person lays the film holder in front of them with the darkslides on the left and the flaps on the right. A left handed person does the opposite so the flaps are on the left. When the film holder is in this orientation the film notches should be in the upper left hand corner. This follows the same logic as my PS message above. The film maintains the same emulsion to lens orientation.

    Greg Landrum
     
  16. Jorge

    Jorge Inactive

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    I beleive this is incorrect. If you are holidng a sheet of film and the notches are in the upper right hand corner, the emulsion is facing you or as you put it is on top. If it is introduced this way into the holder the emulsion is still facing away from the septum. The two possible positions in the film holder is top right hand or lower left hand when the holder is facing you.
     
  17. Landrum

    Landrum Member

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    That is absolutely wrong. There is only one correct way, with the piece of film in your hands the emulsion is up when the notches are in the lower riht hand corner or upper left hand corner. Take a piece of processed black and white film and hold it in glancing light on the two different sides and determine the emulsion side like that and then look at the orinetation of notches.

    Greg Landrum
     
  18. JD Morgan

    JD Morgan Member

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    Greg,

    It depends on the orientation of the holder. I hold mine vertical -- long axis of the holder is on the left and right and flap at top.
     
  19. Jorge

    Jorge Inactive

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    Exactly, if the holder is in a vertical position or for that matter the sheet of film is being held in vertical position with your right hand. The notches are in the top right hand corner and the emulsion is facing you. I dont need to go see I used piece of film I have loaded literally thousands of sheets in 4x5, 8x10 and 12x20.
     
  20. Landrum

    Landrum Member

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    You guys are right, I have never seen a person load film like that. It seems counter intuitive to me to do that but if your film hoder is orinted like that then upper right hand corner is right.
     
  21. Jorge

    Jorge Inactive

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    It is funny, I got to thinking about your post and I realize you are placing the holder on the table in the "landscape" position, if done that way, you are also right, the notches are in the lower right hand corner facing the flap, I thought about it because it is how I load 12x20, so wadda you know, we are both right.
     
  22. JD Morgan

    JD Morgan Member

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    I think most people do it in 'portrait orientation.'

    I was a commercial diver for many years, that means working blind most of the time in rather dreadful conditions. The more body contact you have with an object the more tactile sensing and orientation you maintain.

    With the holder in portrait orientation lying flat on a table in front of you angle it upwards 45 deg. flap at top, now bring the bottom (dark slide end) in to make contact with and resting on (depending on the extent of beer consumed on average) your tummy. Right hand holds the film with notches upper right and *I* use my left hand to keep the flap open with my index finger while my thumb rests just below the film track opening and helps guide the left edge of the film into the track.

    Better sensing, orientation and leverage.
     
  23. bpm32

    bpm32 Member

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    I don't think I did a very good job of explaining myself...

    I lay the film holder flat on a table in a portrait position. The flap is at the far end, the slide will pull out toward my stomach. I pull the slide out toward my stomach and flip the flap away from me with my left hand. I then grasp the film and orient it in the same portrait orientation, again flat to the table. At that point, shouldn't the notches be at the "top right"... or the far end, right corner? When I'm finished sliding the sheet in, the notches, as I look down on the film holder sitting flat on the table, are at the far end right hand corner of the film holder. I'm I doing this wrog? I didn't think my photos looked that bad! :D

    I think this is the same thing JD Morgan just described.

    So, if I'm loading this correctly, the emulsion side would be up at that point. Therefore, when I pull the film out, I simply pull it straight out and lay it on the screen, which is again, in portrait orientation. At that point, the notches would be in the "upper right" hand corner, or the far end corner on the right.

    Does it sound like I'm doing it right? I don't think I'm laying the emulsion face down on the screen, but who knows now. :confused:
     
  24. lee

    lee Member

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    just to add to the confusion, I load film in the holder with the notches on the right in the flap area. I hold the holder with the flap away from me and the dark slide toward me.

    lee\c
     
  25. John Koehrer

    John Koehrer Subscriber

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    To confirm last question. Yes, you are doing it right.
     
  26. SkipA

    SkipA Member

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    I position my holders in landscape orientation, but with the end flap to the left and the darkslides pulled out to the right. I pick up the film with my left hand and insert it with the notches in the upper left corner. And I'm right handed. This seems completely natural to me.

    So there! Takes all kinds!