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  1. #41

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    I would like to bring everyone's attention to what may be obvious, but not in a panic. If one ever gets,or even thinks he might have, silver nitrate in his eye, PROTECT IT FROM LIGHT. Cover the eye and,still sheilding it from light, flood it with gallons of water. Then cover it again. Keep it from ANY light and have someone port you to a physician. This may save your eyesight.
    But always wear goggles!
    Happy Belated Groundhog Day,
    Bill

  2. #42

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    Tim - sorry about the diversions. It's the way things often go here...

    Keep us up to date on how things are going.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  3. #43

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    Quote Originally Posted by Kirk Keyes View Post
    Tim - sorry about the diversions. It's the way things often go here...

    Keep us up to date on how things are going.

    Besides that, i'm in testing mode!

    I did try a shorter exposure and extended development with better results, but have other things to do and other hobbies.

    In the long run, I want to have a paper, a dry plate, and a camera, all hand crafted of course. I'll be looking for a lens soon, so keep that in mind if you have a good lead

    T

  4. #44

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    Tim - If you don't have this book yet, it sounds like you will like it:
    "Primitive Photography: A Guide to Making Cameras, Lenses, and Calotypes" by Alan Greene.
    http://www.amazon.com/Primitive-Phot.../dp/0240804619
    It covers how to make vintage-style lenses as well as plate holders and cameras.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  5. #45
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    Quote Originally Posted by tim_bessell View Post
    The speed is pretty fast, my exposures with a 40 watt bulb, 32 in. from the print frame are 16 sec. Could almost be an enlarging paper.
    Hi Tim,

    No question of it. Your most excellent work inspired me to follow through on the issue. Thanks! I wrote a small splat on it here: http://www.thelightfarm.com/Map/Bits...ulsionBlog.htm.

    It's very hard to compare 'speeds' with handcrafted emulsions. There are just too many variables. Commercial products have been carefully worked up over the years to become more and more standardized and conditions/user 'immune'. DIY'ers have more control (and the flip side of control: risk). But, having said that, I'd guess the paper emulsion you've made would make a great enlarging paper. It sounds like you've got plenty of speed for even big enlargements.

    Looking forward to hearing more about your work, especially with developers.
    d
    Last edited by dwross; 02-12-2010 at 04:57 PM. Click to view previous post history.

  6. #46
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    Most commonly, you can compare speeds by using a contact paper and/or an enlarging paper to gain some idea of how you compare. I use Azo (the few sheets sent my by friends from APUG) and Ilford MGIV at grade 2 for comparisons. I make either a contact or enlarged example at a fixed, measured distance from the lamp, and that is how I can compare speeds.

    My contact grade chloride is either identical to Kodak Azo original grade 2 or is about 1 - 2 stops faster depending on the gelatin I use. It is nearly identical in contrast.

    The enlarging grade is close to Kodabromide in general appearance and is grade 2 as well. It is about 5 stops faster than the contact grade and takes an almost identical exposure as the Ilford paper.

    I have posted the comparison prints here before. They are available using search. If they cannot be found, I will post them again. I also measure the H&D curves and plot them for comparison.

    So, we actually can compare speeds. It is not at all that hard, as long as we all use the same reference paper to compare ours with.

    PE

  7. #47

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    PE
    Thanks for the idea on comparing to manufactured paper, it will be handy down the road, when I get the basics straightened out.

    The shorter exposure I mentioned above was 5.6 sec. (w/ a gralab timer) and developed five minutes in ansco 130 undiluted. The results where very similar to the 16 sec. exposure with 2 min. development. I masked the border of this print in preparation for gold toning and noticed a bit of fogging, much to my dismay.

    Denise
    I should have noted in this post that I am using chrome alum as a hardener. With the Arches paper I have no problems with the emulsion bubbling or coming loose, in fact, after final washing I can pat the print dry with a paper towel. The other paper I tried, Fabriano, was a complete failure.

    Glad to hear I gave you a little push to investigate the speed potential of your paper.

    T

  8. #48
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    Interesting. I give mine 1' in Dektol 1:3. That seems to work fine. This indicates a coarser grain and perhaps other halides being present.

    Your work is excellent. Good luck as you go on. Just post a note or PM me for any help you might need.

    PE

  9. #49
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    Tim,

    Thanks for the intel on chrome alum/Arches. Arches is a beautiful paper that works well with glyoxal, too. I've never used chrome alum directly in my paper recipes, just sometimes in the fix. It's interesting that it didn't work with Fabriano. I'll have to put that to a test sometime. Gotta love a field that keeps you happily solving enough puzzles for a lifetime. Take that, Sudoku!

    Ron,

    Could you do us a favor? I'd love to have you post a couple of Stouffer 21-step tablet prints from your papers in Dektol. I can't turn up the comparison prints you mentioned (you're just too prolific a poster! ) For that matter, I'd love to see more of your work get posted here on a regular basis. You don't have to post recipes. We can wait for your book. But, some examples of actual results (i.e. prints and/or plates and/or film), not just H&D curves and snapshots of lab setups, could be just the inspiration to drum up pre-sales!
    d

  10. #50
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    Print comparisons

    In the prints below, I have first posted the reference using Ilford MGIV paper with an on-easel enlargement at f11, 12" with 1' in Dektol 1:3. The remaining prints are made using the same process. The filter was grade #2.

    Print #2 is the Azo type grade 2-3 paper with 8" exposure, #3 is my enlarging emulsion exposed identically to the Ilford paper but without filtration.

    The curves in #4 represent the actual Stouffer curves from the Azo experiments and are from right to left, My Azo type soft (~2), Azo grade 2, my Azo medium (~2-3) and my Azo hard (~3-4).

    The next two are comparisons of my Azo medium grade and Azo grade 2. The last photo is an uneditied or cropped photo with both the Azo and Azo scanned on one pass (doing separate scans changed the relationships of the images as you can see from the previous two photos) with identical process and exposure conditions. I used an old negative from the 20s to get that "old time" look.

    In the early stages, I used the MacBeth in the photo, then I went to the strip chart and now I am doing a strip chart and a Stouffer wedge.

    The strip chart is a Kodak step wedge. It is as valid as the Stouffer wedge.

    I hope this helps.

    PE
    Attached Thumbnails Attached Thumbnails Ilford MGIV test copy.jpg   Azo type.jpg   enlarging type.jpg   curves.jpg   Azo type print medium.jpg  

    Azo grade 2.jpg   Azo and azo type.jpg  

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