Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,559   Posts: 1,573,291   Online: 947
      
Page 2 of 2 FirstFirst 12
Results 11 to 15 of 15
  1. #11
    gandolfi's Avatar
    Join Date
    Jan 2005
    Location
    Denmark
    Shooter
    Large Format Pan
    Posts
    1,804
    Images
    370
    Quote Originally Posted by Graeme Hird
    Oh dear - as an Aussie, I completely got the wrong end of the stick when I read the thread title. "Dags" are either "uncool" people who play the fool or the dirty wool around a sheep's backside. Shooting them has never been high on my list of "dream" assignments .....
    that made my day!

    (I never shoot any thing - and I can't stand that expression...)

  2. #12
    Carol's Avatar
    Join Date
    Mar 2003
    Location
    Australia
    Shooter
    35mm
    Posts
    327
    Images
    1
    Chuckle. Another Aussie tricked by the title. Bit hard to get a sheep to sign a release form.

    Sorry off topic.

  3. #13
    DimDim's Avatar
    Join Date
    Mar 2005
    Location
    Antwerp, Belgium
    Shooter
    Multi Format
    Posts
    32
    Quote Originally Posted by JG Motamedi
    I suspect that the "circular 'zones'" you describe are due to either moisture on the plate before sensitization (Do you heat them before putting them into the iodine? This is very important). It could also be due to not enough iodine fumes in the box or quite possibly your polish.
    Jason,

    Thanks for the PDF. It's good to get another point of view on this matter.
    About the stains. The attached image is an extreme example of it.
    I don't think moist can be the problem and I do heat my plates with a hairdryer just before I expose them to iodine.

    I had problems with insufficient vapour and I upgraded my coating box with a heating element but that turned out too heavy. Plates looked like classic B&W emulsion after only 30 seconds. I have to finetune this as I easily loose the spectral colours and get a greyish blend, even if I only activate the heating for 20 seconds and wait for about a minute to start exposing.

    Cheers,

    Stefan
    Attached Thumbnails Attached Thumbnails stain.jpg  

  4. #14
    JG Motamedi's Avatar
    Join Date
    Dec 2004
    Location
    Portland, OR
    Shooter
    Large Format
    Posts
    469
    Stefan,

    I suspect the problem is that the fumes are too localized; I would then guess that either there isn't enough space in the box for even coating or there aren't enough fumes. Perhaps the iodine is too close to the plate? My box has about 75mm between the iodine and the plate. Is you iodine evenly dispersed through out the box? I have never paid much attention to this, but if the iodine is too close to the plate this may be a possible cause.

    I would be very concerned about heating the iodine. I think this is very dangerous and not at all necessary. At a room temperature of 20 degrees, iodine should easily produce enough fumes. Usually I try to "build up" fumes in the box before inserting the plate. Would it be possible to do this with your box? Build up the fumes for 15 minutes (with no heat) and then insert them?

    best regards,

    jason

  5. #15
    DimDim's Avatar
    Join Date
    Mar 2005
    Location
    Antwerp, Belgium
    Shooter
    Multi Format
    Posts
    32
    Hi again,

    The distance could be a problem. I guess it's only 50 mm away from the plate nuw but to improve this I have to build a new bottom section for my box.
    I lost some time because I had no clue about the sort of reaction I had to expect from Iodine. I remember leaving the box out in te sun for hours without any visible reaction. (that was with a dose of bisublimated Iodine - tiny little balls)
    Then I used crystals. I expected them to react in mid air but again nothing happened. So I sealed the inner tray of my box and put it in the sun again. You can see the different tints of vapour that I obtained. Can you hint me on how intense it should be?
    I know the heating sounds tricky but my box is sealed well and I wear a high quality breathing-mask at all times.

    reagards,

    Stefan
    Attached Thumbnails Attached Thumbnails pink.jpg   purple.jpg  

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin