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Thread: PMK or Divided D76

  1. #11

    Join Date
    Dec 1997
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    Baraboo, Wisconsin
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    7,697

    PMK or Divided D76

    DJ - When you say you see a difference, do you mean you've made a series of identically exposed negatives, developed one set in PMK for the "correct" PMK time for the contrast range of the scenes in that series of negatives as determined from proper testing, and the other set in a "normal" developer for the "correct" time for that developer as determined from proper testing, made the best print you can make of the PMK negative, and then were unable to duplicate that print from the "normal" negative? (i.e. your PMK prints were visibly different in some way from your "normal" prints despite your best efforts to make them appear identical). If that's what you're saying I'd like very much to see several of the comparison prints you used. If you're agreeable let me know by e mail and I'll send you an envelope with the postage prepaid so that you can send the prints to me and I'll return them to you in a couple days. I don't mean this sarcastically or as a snide "I dare you" challenge, I'm seriously interested in seeing your results because three people, two of us reasonably knowledgeable photographers and the third a photography teacher, tried to do this and we were unable to do it (i.e. we could always make a print from the "normal" negative that duplicated the print from the PMK negative). OTOH, if this isn't what you've done, and if instead you're just looking at some negatives developed in PMK and concluding that they look "sharper" or "better" than some entirely different negatives developed in other developers, then I don't think your observations are very significant or valid. Even assuming you can draw valid conclusions about two developers by looking at a random bunch of entirely different negatives (which I don't think you can do), if the differences in the negatives don't translate into differences in the prints, then who cares what the negatives look like?
    Brian Ellis
    Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
    a mile away and you'll have their shoes.

  2. #12

    PMK or Divided D76

    There is an interesting article on www.unblinkingeye.com called the effects of Pyro Stain. While this article is concerned with the results of pyro VS D-76 for platinum contact printing it might provide some insight for those interested.

    Cheers

  3. #13

    Join Date
    Mar 1999
    Posts
    769

    PMK or Divided D76

    Hi Brian

    I should preface this by saying that I don't consider my testing very exhaustive or anything of the kind. I was more interested in finding something that worked for me and getting on with making pictures. What I stated above was my understanding based upon both the test I did, and in looking at a large number of negatives that I have shot and developed in the different developers. Details about test below. However, as much as I like data based upon tests, I think the second part (my subjective opinion based upon comparing different, non-test negatives) is important also because we shoot varied scenes. And the kind of scene doesplay a part in determining whether a particular variable (type of developer) makes a significant difference or not. And it is something that would be too onerous to test, so I fall back on my comparisons of negs.

    First, the test. Yes, I exposed a few scenes and developed them in a Catechol developer and D23. The basic idea was to develop them to the same contrast - I used the methodology Phil Davies outlines in his book. What I find is that for 'normal' scenes (i.e., a scene consisting of about 5 stops for luminance differences - typical zone III to zone VII kind) and a decent amount of texture, I could not see any differences between the two developers (both in the negative and in the print) - there were some differences, very subtle stuff that could be as much due to minor differences in curve shape etc (see below) but nothing dramatic. Depending upon the kind of scene etc., you may find a difference in that one developer may exhibit enhanced acutance or adjacency effects etc., although this is going to depend upon the scene and how much detail there is and so on. However, when it comes to other kinds of lighting situations (e.g., a long range of luminance values, a contraction negative, low local contrast in the highlights), the staining developer held texture in the highlights more easily.

    Caveats: There were some other differences between the two developers. Most importantly, I'm afraid given my processing conditions, I could not get idential curve shapes, the D23 did have a shoulder compared to the Catechol developer.

    Two negatives (not part of my test) that reveal this most clearly (to me) are pictures of ice on a lake with the glare of the sun on the ice in one area. The D23 negative is 'blocked', if I expose the negative enough to print through, I get a textureless 'grey' - I interpret this as meaning that irradiation within the emulsion has reduced local contrast in this area considerably. However, the Catechol developed negative prints with texture - I interpret that to be due to the tanning that prevents irradiation.

    I did not mean to imply that your tests were wrong. I was merely adding another data point to the discussion. It is entirely possible that there is something idiosyncratic such as 'kind of scene' that determines whether one will see differences between developers etc. And I think the point you make is a valid one. If the kind of pictures one wants to make does not benefit from staining developers, there is little to be gained by going to PMK or anything like that. Hutchings himself states that pyro's advantages tend to reveal themselves in 'difficult light' - I interpret that as meaning that certain kinds of light and certain kinds of scenes will be handled more easily in pyro (and I'm sure there are other kinds of scenes that are more easily handled by other kinds of developers).

    Cheers, DJ.

  4. #14

    Join Date
    Jul 1999
    Posts
    84

    PMK or Divided D76

    I did fairly extensive testing last Summer, using 120 film (Ilford Delta 100 and 400) developed either in XTOL 1:1 or PMK. (I took 2 exposures of each scene, one for XTOL the other for PMK processing, so it was a true side-by-side test). My first impression was, "wow, these PMK negatives are truly spectacular", which is where some of the PMK-mystique may stem from. When making carefully contrast- balanced prints, most of the mystique disappeared. I am not saying there was no discernable difference anymore between the prints (which would be surprising, since the densitity curves of film/developer combinations will never be the same) but I had a hard time to say which one was "more beautiful". Sometimes the edge went to the PMK, sometimes to the XTOL print. When making HUGE enlargments (20x24 from 120 negs) then the PMK negs always had better acutance. These are some of the sharpest negs I ever got. They are as good as TMX in Rodinal 1:50, but without the grain! For LF photographers who don't need to enlarge quite as much, this may not be important. In MF, I am sticking with PMK though. The largest drawback to me is not the toxicity (no problem if one works carefully) but the loss of film speed (a little more than 1 f-stop).

  5. #15

    PMK or Divided D76

    Anyone tried a kind of "divided PMK" ? This is not a joke or for the sake to try something original. I have been using PMK since 1996 and I found it gives superior results than non taning developers in situations of high brightness range ; otherwise, the results are close, but it is easier to stick with one developer you know well. I am a PMK enthousiast ! A good test I made once : take a picture of a nautilus cut in half (like the one taken by Weston) ; the glaring surface and the sharp edges of the shell will be shown with micro details and a subtlety in highlights that is better recorded. In MF and LF, grain is not a problem with PMK. In 35 mm, grain matters : you need a beautiful grain wether it is discret or clearly visible. If you use films not faster than 100/125 ISO, grain is not a problem with PMK. But for 400 ISO in 35 mm I find the shape of the grain in the shadows too similar to what you get from an underexposed color negative film : disturbing. Well, a D76 grain is more beautiful in this part. I like TMY for 35 mm ; I won't say it is the best film : I like it. I tested all 400 ISO, and found I prefer this one in 35 mm because of the resolution, size and shape of the grain. Once the contrast of TMY is controled, I find it a good film. TMY has the same problem of grain in the shadows than any other 400 ISO film in PMK. I like to take pictures with "contre-jour" or high brightness range ; and PMK does a good job in highlights. I wondered if Divided D76 could give me the grain of D76 with the highlights of PMK. I tried but the grain was there but not the same quality of PMK highlights. TMY can record a lot of information in highlights, but divided D76, while keeping highlights with details, those details were flater than what I get with PMK. To get advantages of both developer, I tried a divided... PMK. For the first bath, I use 5 g of metol with 50 g of sulfite. For the second bath, PMK. 4 mn in bath A (70?F/21?C) and 4 mn in PMK. No rinse between the two baths, like any two baths development. I use an alkaline bath after fix (as in the PMK procedure). The negatives have a stain, but not as much as with a normal PMK development. The result ? I get the grain I like in the shadows and the highlights print with all the details I am looking for. Contrast can be controled with varying times in A and B or with temperature : low contrast : 3+3, high contrast : 5+5. It would be interesting to have your opinion on that subject. And be lenient with my English...

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