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  1. #11
    TheFlyingCamera's Avatar
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    You're saying your negs look THIN when you're cooking them that long in the soup? I think you may have other issues then, but let's see your negs first. What you think is thin and what I think is thin may be two different animals. Or you may have some other issue that is causing an excess of base+fog density (some kind of UV blocker in the film??? who knows...)

  2. #12
    Kerik's Avatar
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    Just a few quick thoughts:

    -First, I disagree with Don regarding the Na2 mix. For in-camera negs, trying to standardize on one contrast mix will just drive you nuts. To me, the purpose of Na2 is the ability to adjust your contrast mix, not standardize on one. With digital negs, it's a different story since it is much easier to make them virtually identical in DR.

    -Three drops of 20% Na2 in an 8x10 print is a LOT, as I think you've discovered.

    - For HP5+, I highly recommend Rollo Pyro in trays. I rate it at 160 and develop for about 8 or 9 minutes at 70 degrees with more or less continuous agitation. With this combination I am able get very good results with HP5 without the need to pump in a lot of Na2. I had much poorer results with PMK and Pyrocat HD. I use a UV box with 4-foot 40 watt tubes and my exposure times are usually in the 6 to 9 minute range. Let me add that I typically only use HP5+ for "normal" lighting conditions. For low contrast, soft light FP4 or TMY are much better choices.

    Hope that helps a bit...
    Kerik Kouklis
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    2014 Workshop Schedule Online

  3. #13
    wilsonneal's Avatar
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    Quote Originally Posted by Kerik View Post
    -Three drops of 20% Na2 in an 8x10 print is a LOT, as I think you've discovered.

    Kerik:
    Thanks, but wait. Here's my disconnect. If you look at Arentz's chart here: http://www.dickarentz.com/na2.html
    you can see that for a 1.4DR neg (like, close to IDEAL for PtPd and he even calls it "Medium"), he specs 1 drop of 20% for a 4x5. 6 drops FO, 6 drops PD, 1 drop 20% NA. That would equal 4 drops 20% NA for an 8x10, right? My understanding of Arentz is that he's specifying 12 drops for a 4x5 and 48 total drops for an 8x10?

    So based on that, 3 drops of 20% NA2 is about right for a the middle of the scale? Or is there another way to interpret this chart, which is the basis for my method.

    Thanks.
    Neal

  4. #14
    Kerik's Avatar
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    Wilson,

    Hmmm... Well, let me put it this way. I was a "Beta tester" of Na2 for B&S when Dick Sullivan first stumbled onto its properties several years ago. So, I have not adopted Arentz' approach (which for my way of working is way too complicated). I've been platinum printing long enough (17+ years) that I prefer to work much more intuitively. I don't use a densitometer (although I actually aquired one recently but I've yet to use it). I prefer very warm prints, therefore I want to use pure palladium with little or no Platinum (Na2 or otherwise). I process my negs so they will print well with either no Na2 or just a bit. I think the most I've used is 6 drops in a 14x17 print (which is roughly equivalent to 2 drops in an 8x10).

    So, while 4 drops may be Arentz' middle range, it's off the scale for how I work. I'm not saying Arentz is wrong, he's absolutely one of the best pt/pd printers around, he just takes a different, more analytical approach where I prefer to fly by the seat of my pants and rely on my own experience. This ain't rocket science, and I should know since I work for a rocket manufacturing company in my "spare time".
    Kerik Kouklis
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  5. #15

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    Long exposure times with any staining developer are almost always the result of over-exposure. The plain and simple fact of the matter is that stain is proportional to silver density, and exposure with any process is based on shadow density, where there is very little stain. If you measure the shadow density at Zone III of correctly exposed stained and non-stained negatives there should be little difference, certainly no more than about + log 0.10 for the stained negative. And that is about what I see in my own work, i.e. correctly exposed stained negatives required about 1/3, or at most 1/2 stop more exposure non-stained negatives.

    Unfortunately much of the literature on pt/pd printing suggsts that we need to make very strong negatives for the process, and many people wind up giving more exposure than is needed. In my own work I find that when developing for the high contrast needed for alternative printing an EFS of about 2X the maker's rating is required to avoid over-exposure. For example, I generally rate TMY at EFS 600, or even 1200 when exposures are based on incident readings in the shadows as in BTZS procedure.

    Another issue with staining developes is B+F. All of the staining developers will develop more B+F or general stain (which adds to printing time) with constant rotary agitation (say in tubes or in Jobo) than with tray agitation. For that reason many good pt./pd printers who use Pyrocat-HD, Tillman Crane for example, develop in trays. I develop some ULF film with rotary develoment in tubes with Pyrocat-MC, which contains ascorbic acid, because this developer gives a lower B+F with long develoment than Pyrocat-HD. However, whenever practical I develop in tubes with minimal agitation procedures, which gives the lowest B+F stain of any method with staining developers.

    Sandy King
    Last edited by sanking; 02-08-2007 at 08:02 PM. Click to view previous post history.

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