First contrast reduction mask. How to control the dust?

Discussion in 'Enlarging' started by SeanEsopenko, Jul 24, 2011.

  1. SeanEsopenko

    SeanEsopenko Member

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    [​IMG]

    So I did my first contrast reduction mask. Without the reduction mask Fuji CA paper was just too contrasty, blowing out the sky almost completely and rendering the upper-left tree into complete darkness. a 300 dpi scan of this image with the contrast reduction mask can be found here. My very first try (and a failure) can be found here.

    I exposed Ilford FP4+ 4x5 film under the enlarger with white light (0,0,0) on my Omega dichroic II's "low" setting for 1 second. I exposed 5 negatives from f 5.6 to F22 to see the effect and after some prints with a few of them I liked the F22 shot the most. They were tray developed in D76 1:1 for 9 minutes (about iso 50 according to ilford's documentation).

    I feel quite liberated now that I know how to do masking and while the registration wasn't perfect it's not as intimidating as I thought it was. The only serious trouble I'm having is dust exposing into the contrast mask. I used a rocket blower like crazy on every single surface (colour negative, b&w negative, plexi glass for weight) but dust was exposed into every single reduction mask I made.

    Any advice on how to control the dust?
     
  2. Mike Wilde

    Mike Wilde Member

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    Whenever I need to combine negs in any form, I dig out my old 'Zerostat' record static eliminator electrostatic 'gun'. This thing does wonders to make dust run away.

    I try to wipe down the floor and horizontal surfaces in the darkroom on a semi regular basis with a wet cloth. I also run a room air filter for a few hours when dust seems to get out of hand.

    Relative humiduty can also be a challenge. Whenever the little electronic high/low thermometer/humidistat says it is lower than 35% RH I get some sort of humidification works either in the furnace, or just a tray of water in the darkroom with the filter blowing over it going. Too dry and dust is a killer to control due to static buildup on film bases when pulled out of the filing pages I keep them in.
     
  3. Diapositivo

    Diapositivo Subscriber

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    Is the thing this thing?

    http://www.2spi.com/catalog/photo/zerostat.shtml

    Do you use the "negative ions" flow or the "positive ions" flow, or both?

    That would be VERY interesting for darkroom work and for scanning. I have never used antistatic sprays for fear of leaving residues on my beloved creatures.
     
  4. michael_r

    michael_r Subscriber

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    I've always wondered if those guns work. Never tried one. I did try a staticmaster brush a few times, but I never liked the idea of brushing the negative, and then I also heard John Sexton call the polonium thing baloney-um. So I gave up on it.

    Perhaps a combination of this gun thing and then a blast of compressed air would work. I find sometimes you can use a rocket blower until the cows come home but it simply doesn't generate enough pressure to blow all the dust off. Compressed air, or canned air works much better for me. But if the gun does indeed eliminate the static, perhaps then the rocket would work better because the dust would come off easier.
     
  5. Bob Carnie

    Bob Carnie Subscriber

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    For internegs, dupes and contrast masks or any masks, the most important thing, was isolating a small room to do the work, keeping the humidity way up and constant cleaning of the room.

    We did use canned air , but really the room condition was of most importance.
     
  6. Mike Wilde

    Mike Wilde Member

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    The gun works for me. Mine is red and circa 1980, but the one your referenced site shows in blue appears to be made in the same mold.

    Some times you squeeze away from the object, and relese near the object, other times you swezze near the object of interest, and release it away from the object to control which ion is laid out near the object of interst. I think the static charge for film varies depending on the material it was dragged across.

    I still use the polonium 'activated' brush after the zerostat treatment, because it does have a very nice brush for the size of area it can swipe to dislodge the now neutralized dust
    (even though the polonium strip decayed beyond usefulness many years ago).

    I blow it out with compresed air or vaccuum it, depending on the particular cleaning phase I am in at the time.