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  1. #11
    smieglitz's Avatar
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    Looks similar at home. The images are much more blue onscreen than on the actual print.

    I'm amazed that there are 18 distinct steps printed out on the image with the stepwedge. That's a total density of about 2.75 or so.

    Joe

  2. #12

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    Joe... very interesting about the gelatin and the tonal shift. I have noticed with platinum that slight variations in image tone occur with different proportions of gelatin to other agents in the sizing mix for the paper. I do wonder though if there is a threshold where the addition of too much gelatin to the mix will result in a decrease in contrast... anyway thanks again for sharing your investigations...

  3. #13
    Photo Engineer's Avatar
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    Gelatin type, level and bloom index were used in early formulations of many silver halide based light sensitive sytems to control contrast. The pH was another method.

    So, I'm not surprised at these results, nor would I be surprised if other addenda commonly used in the photo industry varied the contrast and dmax.

    One thing that I believe to be common in any print material is that it requires about 100 mg / dm sq of silver metal (or perhaps any metal?) to achieve both a good dmax and a good contrast in an image (with average developers). If you cannot put that down on your surface, something will suffer. A level of 50 mg / dm sq might yield acceptable results if the form of the metal were suitable. As silver becomes more finely divided, the achievable density per unit weight goes up. So, the development method is critical to achieving a given density from a different level of silver.

    PE

  4. #14
    smieglitz's Avatar
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    Here's a bit more info and a few more examples:

    I tested several different salt and albumen recipes this week. For salted paper I tried a plain 2% ammonium chloride salt solution, a salt mix (previously posted in the thread) with 0.5% gelatin, and the same salt mix with 3% gelatin. The latter was not good. I think the extra gelatin somehow reacted with the salt and prevented the prints from clearing as well. They had poorer contrast than either of the other variations. Without some gelatin the prints are very matte and lower contrast.

    I also tried the same plain ammonium chloride and mixed salts in a standard albumen and tried single- vs double-coats of both salt and albumen, tried hardening in a drymount press vs unhardened double coats, hardened vs unhardened single coats, fixing before and after toning and a couple variations in toners. The first two images in the attachment show my favorite results.

    For salted paper I ended up preferring a mix of salts and 0.5% gelatin toned in Clerc's gold toner to produce a purplish hue, as in the 1st image. The 2nd image is the same mix of salts mixed in the albumen and single-coated without heat hardening. I modified the Clerc's gold toner by adding 10 gm of sodium citrate to it to produce a more purple tone. The 3rd image is a double-coated albumen print with the first layer heat-hardened. The salt mix was the same for this print but no citrate was added to the gold toner. The latter print is warmer and also exhibits pronounced coating streaks which are absent in the salt print and very minimal in the single-coated albumen print. So, other than preferring a salt mix over plain ammonium chloride, the moral of this story appears to be K.I.S.S.

    All images on Cranes Cover natural with 20% silver nitrate bath at pH2 for the sensitizer.

    Next up is comparing brush or rod coating to flotation methods.

    The negative for the salt print is 5x7 Efke 25 @ EI 12 developed in HC110-A for 5.25 minutes 68F and then intensified in selenium toner 1+3 for 5 minutes. The negative's highlight transmission density on the cheek is about 2.05 above fbf. The albumen negative is the same film only at EI 25, developed and intensified as the other. Cheek highlights are about 1.90 above fbf on that negative. Lighting was an electronic flash in medium softbox with a silver reflector panel to one side as fill. Scans reduced to half-size to fit the posting limit.
    Attached Thumbnails Attached Thumbnails salt_albumen_02.jpg  

  5. #15

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    Quote Originally Posted by smieglitz
    Favorite papers or unusual techniques (e.g., Schaeffer where he salts, sensitizes with 12% AgNO3, then rinses and sensitizes again with 1% AgNO3) would be welcome.
    What does coating with 12% AgNO3, rinsing, and then coating with 1% AgNO3 achieve?

  6. #16
    smieglitz's Avatar
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    Quote Originally Posted by circumstance
    What does coating with 12% AgNO3, rinsing, and then coating with 1% AgNO3 achieve?
    If I read Schaeffer right he is postulating that the excess sodium chloride will be removed by the water rinse following sensitizing with AgNO3. The 1% silver nitrate bath is presumably to ensure an excess of silver over chloride in the emulsion.

    But, by that logic only insoluble silver chloride would be left in the paper after the rinse has washed away the sodium or ammonium chloride salts and the subsequent 1% silver bath probably isn't needed since there would be no chloride left to react with it. That's my guess anyhow. (But, note I'm not a chemist so take it with a grain of ... uh ...umm ... salt. Sorry for that one )

    I have had better results just using a more concentrated and acidified silver sensitizing solution than using Schaeffer's method.

    Joe

  7. #17

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    Joe,
    Thanks for posting your results. This might complicate things a bit, but since you're running the variables through anyway, I might as well bring it up. For my albumen prints, I find that I get more consistent and predictable results by double coating with the salted albumen (2% sea salt). I normally albumen coat with brush. The second coating of albumen is applied while the first is semi-dry/moist. I then float the paper in 15% silver nitrate. I never got clean results from coating silver with any kind of brush, hake or othewise. Nor could I get consistent results from using a puddle pusher. I get streaks with both methods. And so following David Goldfarb's recommendation, I switched over to floating the albumen coated paper in the silver solution. I now have a much higher level of success, and a much reduced level of frustration.

    Compared to a single albumen coat, I get better density, contrast and definition from a double coating of albumen. I'm no chemist, so I'm guessing that the double coating makes more salt available to bond with the silver nitrate, thus increased density. Plus the added gloss from a thicker albumen coat also helps.

    I haven't been working with albumen for very long, but after many trials and errors, I have finally settled on two types of papers. Although rather expensive, Fabriano Artistico is my favorite. It gives me consistent results. Canford cardstock in three varieties (Snow White, China White, and Ice White) also work well, primarily because the paper structure holds multiple coats of albumen very well.

    Maybe if you tried double coating with the albumen you'd get the contrast that you like.

  8. #18
    Jim Noel's Avatar
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    I notice the papers mentioned probably do not give any gloss to the albumen prints. Since typically 19th and early 20th century albumens were glossy, I prefer that look.

    In order to get a decent gloss I went to Strathmore 500, plate finish, single ply. A single application of albumen works well on this paper for me. Also by using a gold/thiocyanatge toner I can get the typical purplish color when I want it.
    [FONT=Comic Sans MS]Films NOT Dead - Just getting fixed![/FONT]

  9. #19
    smieglitz's Avatar
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    Quote Originally Posted by Jim Noel
    ...In order to get a decent gloss I went to Strathmore 500, plate finish, single ply. A single application of albumen works well on this paper for me. Also by using a gold/thiocyanatge toner I can get the typical purplish color when I want it.
    Jim,

    I just participated in a wetplate collodion workshop last month from master tintypist John Coffer. Strathmore 500 plate is also his choice of paper to duplicate the look of 19th century albumen prints from collodion negatives.

    Joe

  10. #20
    David A. Goldfarb's Avatar
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    I'm also using Strathmore 500 plate, one ply. I've experimented a bit with 1-ply. 1-ply is easier to work with.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

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