Darkening on the endge of the neg - 120

Discussion in 'Darkroom Developing and Printing' started by Peter Chant, Jul 2, 2007.

  1. Peter Chant

    Peter Chant Guest

    Any hint what is causing the edges of the neg to be darkened?

    Example, three b&w pictures at the top of the page.

    http://homepage.ntlworld.com/peter.chant/gallery/Iceland/

    It's not a light leak as the darkening only occurs on exposed areas, not
    between them.

    Details:

    FP4+ exposed at 80ASA
    10.30 min in Rodinol 1:50 at 20 degC
    Agitated 10 sec every minute.

    I'm wondering if it is something to do with agitation.

    Any ideas?

    Pete
     
    Peter Chant, Jul 2, 2007
    #1
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  2. Peter Chant

    Peter Chant Guest

    Peter Chant wrote:

    BTW - painfully aware of the serious faux pass with the vignetting lens
    hood.

    Pete
     
    Peter Chant, Jul 2, 2007
    #2
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  3. Peter Chant

    Rob Morley Guest

    Could still be a light leak through the shutter, but it's not
    characteristic of that (too linear). If it was from processing you
    wouldn't expect it to be in the same place on each frame. I wonder if
    it could have something to do with a temperature difference between the
    film and the camera body when you were shooting.
     
    Rob Morley, Jul 2, 2007
    #3
  4. I assume SS tank/spiral reel, no extra space in the tank -
    the reel isn't sliding in the tank.

    I agree, looks like an agitation problem to me. Either:

    o Too much: the turbulence at the edge of the film is
    developing the film at the edges faster than the middle.

    o Too little: the developer in the middle of the film is
    becoming exhausted.

    I would guess too little. Dilute Rodinal exhausts pretty
    quickly. There are those that swear by/at ultra dilute Rodinal
    and 'stand' development to get a sort of unsharp mask effect
    from developer exhaustion. I've never tried this with 120,
    but with 35mm the development is even enough across the
    film.

    About 10 quick inversions and a bit of a quick twist back
    and forth - taking 5 seconds or so in total - every 30 seconds
    is my agitation method. Everyone has their own, I am sure.
    I use D-76 or HC-110 for 120 HP/FP/TMX/TX/Delta.
     
    Nicholas O. Lindan, Jul 2, 2007
    #4
  5. Failure to clean the wetting agent completely from the reel before using it
    again.

    If wetting agent adheres to the reel, then when the developer hits it, it
    causes the developer to penetrate the emulsion more completely, thereby
    developing the parts of the film nearest the reel more quickly than the
    rest.

    You might try adding a little stop bath to the rinse water -- the acid in
    the stop bath will neutralize the alkiline wettine agent. Then rinse the
    reel in water until you can no longer smell any trace of stop bath :)

    I don't know if I'm right about this, but at least it's a plausible theory
    :)
     
    Andrew Koenig, Jul 2, 2007
    #5
  6. Peter Chant spake thus:
    *Definitely* an agitation issue. How about sacrificing a few rolls of
    film and experimenting with different agitation methods? Find the one
    that yields the most even development. Would be worth the time and expense.


    --
    Any system of knowledge that is capable of listing films in order
    of use of the word "****" is incapable of writing a good summary
    and analysis of the Philippine-American War. And vice-versa.
    This is an inviolable rule.

    - Matthew White, referring to Wikipedia on his WikiWatch site
    (http://users.erols.com/mwhite28/wikiwoo.htm)
     
    David Nebenzahl, Jul 2, 2007
    #6
  7. Peter Chant

    Peter Chant Guest

    Rob Morley wrote:

    Don't think it was the camera.

    Its a Mamiya TLR, so its a leaf shutter, I would have through that would
    produce a slodge or arc rather than any edge effect. Also, although there
    were Icebergs it was not actually that cold. At the time I took those
    shots I think I was wearing a T-shirt and a very thin jumper.
     
    Peter Chant, Jul 2, 2007
    #7
  8. Peter Chant

    Peter Chant Guest

    Patterson plastic tank.

    Slight update it was HP5+ developed for about 10:30 at 20 degC
    Odd that I have not seen this before.
    I could try going for 1:25, I suspect from a bit of look at the massive dev
    chart and a bit of guestimation / interpolation that 5:20 might be about
    right. I ought to do the sums properly.
    Although that may be possible using the plastic snap on lid it appears to me
    that the tank is not made for that kind of agitation. It does have a thing
    you stick in it to twiddle the reel.
     
    Peter Chant, Jul 2, 2007
    #8
  9. Peter Chant

    Dana Myers Guest

    Looks like agitation to me, or perhaps an incomplete
    fill in the tank. Do you used a daylight tank? How
    do you agitate?

    Dana
     
    Dana Myers, Jul 2, 2007
    #9
  10. Peter Chant

    Peter Chant Guest

    Yes, the Patterson one. I twiddle the thingy to rotate the spiral, 10
    seconds every minute.

    Perhaps making up 600 ml of developer rather than the 500 suggested on the
    bottom of the tank might help.

    Pete
     
    Peter Chant, Jul 2, 2007
    #10
  11. Peter Chant

    Dana Myers Guest

    Are you agitating with the "twiddler"? That pretty much explains
    it. The one time I tried using the twiddler in my cheap knock-off
    of a Patterson tank, I got uneven development, too. I didn't think
    it would work, and it didn't. I only agitate by inversion; the cheap
    Patterson clone was retired because the lid didn't make a very good
    seal. I mostly use stainless tanks/reels now, though I still have an
    ancient plastic Unicolor tank/reel for when I need it.

    Dana
     
    Dana Myers, Jul 2, 2007
    #11
  12. Agreed. The problem is likely over/under-agitation - as the reel is
    twirled new developer enters/flows through the flanges to the edge
    of the film and the developer in the center of the film never gets
    exchanged. The edges of the film get more agitation than the center.
    As to over Vs under, it depends on how you look at it.

    The Paterson tank isn't made for inversion agitation with a 120 reel
    in it though you could try it.

    I recommend getting a stainless steel reel and tank. The go for a
    few farthings on ebay.

    Honeywell-Nikor, Kinderman and Hewes are the makes to get. The
    Japanese all-s.steel clones work but they don't survive drops
    very well so beware bent reels and dinged tanks.
     
    Nicholas O. Lindan, Jul 2, 2007
    #12
  13. Peter Chant

    Dana Myers Guest

    Here's a simple experiment. Put the reel into the tank, with
    no film in it, and fill the tank with 500ml of water and see
    how submersed the reel is. If it's just at the top of the
    reel, that's not really enough; add more water so the reel
    is more than 5-10m submersed, and measure the total amount.

    But, I tend to think you'd be way better-off with a stainless
    tank that you can invert. Switching to agitation-by-inversion
    will probably influence the development time (probably shorten
    it a bit), so you'll want to run a test roll after the switch.

    Dana
     
    Dana Myers, Jul 2, 2007
    #13
  14. Peter Chant

    Peter Chant Guest

    Dana Myers wrote:

    Well, it looks like I will put the lid on and try inversion. I suspect
    Nicholas's example is probally a place to start unless anyone has any other
    pointers.

    Unless I want a stanless steel cage that can take by the looks of it two
    dozen reels and goes in a gallon tank it looks like I can't get stainless
    steel kit here at the moment! Not even ebay!

    Pete
     
    Peter Chant, Jul 2, 2007
    #14
  15. Peter Chant

    Rob Morley Guest

    Except, of course, if it's on the edge like you said - for some reason I
    was thinking it was next to the spools. :-\
    As everyone else said - agitation. I think I need a new brain.
     
    Rob Morley, Jul 2, 2007
    #15
  16. Peter Chant

    Peter Chant Guest

    Nicholas O. Lindan wrote:

    See your point - you are just moving the stale developer futher along the
    film.
    I can - I see what you mean, little air space, I suppose the developer would
    move around.
    Thanks. It looks like not this week on ebay though, at least in the UK,
    will keep a useful eye out.

    Pete
     
    Peter Chant, Jul 2, 2007
    #16
  17. Peter Chant

    Peter Chant Guest

    Rob Morley wrote:

    It just probally needs a rest and a service. Perhaps the light seals are
    going...

    ;-)

    Pete
     
    Peter Chant, Jul 2, 2007
    #17
  18. Peter Chant

    Peter Chant Guest

    With the recommended 500ml the reel was submersed by about 8-10mm.


    However, for no good reason I used hot water. That resulted the hot water
    heating the remaining air in the tank when shaken and the top popping off
    showering me and the kitchen in water - fortunately.

    Good reason to get a tank with a more secre lid. Looks like there is enough
    space to give a fair bit of mixing with inversion.
    Cheers to all who responded in this thread - most helpful.

    Pete
     
    Peter Chant, Jul 2, 2007
    #18
  19. Inversion agitation may cure the problem as suggested
    by others. However, be aware that you may still get a bit of
    overdevelopment at the edges of the film with inversion due
    to the increased turbulance at the edges of the film.
    Inversion agitation does seem to produce more uniform
    development end to end. Twiddle type agitation can also
    cause bromide streaking near the center of the film.
    I've tried both the 10 second agatation every minute
    (Ilford recommendation) and 5 seconds every 30 seconds
    (Kodak recommendation) and don't see any significant
    differece with roll film. However, I have a Nikor sheet film
    tank which has a more restricted flow pattern and with that
    the longer agitation intervals does seem to produce more
    uniform results.
     
    Richard Knoppow, Jul 3, 2007
    #19
  20. Peter Chant

    John Boy Guest

    It would be light, not dark.
    Oh, I am so happy I hung around here long enough to finally read the
    silliest posit. You win!
     
    John Boy, Jul 3, 2007
    #20
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