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  1. #1
    Photo Engineer's Avatar
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    Azo like emulsion in several grades

    I am now able to make an Azo like emulsion in up to 7 contrast grades. This paper is about 1 stop faster than traditional Azo, and has a spectral sensitivity tilted more to the UV than visible region (less blue, more UV).

    Some of the grades are designed to give a softer toe so that there is a longer tone scale with better highlight detail.

    The range is obtained by use of one emulsion formula, but the use of variations in the final coating formulation, so that there is a minimum of lab work involved. In fact, with practice, you can make up one batch of melted emulsion and make 3 grades from it by adding addenda as you coat to vary the end result. So, make the melted emulsion, coat 10 sheets, add an ingredient, coat 10 more and add another ingredient and coat 10 more and you have 30 sheets of increasing contrast. Of course, by varying levels of these ingredients you can obtain custom results of intermediate contrast.

    I have coated it on 4 types of paper. Strathmore Smooth, Vellum, Watercolor and Glossy Baryta. Difficulty increases in the order given, but sharpness is in the order Watercolor, Vellum, Smooth, Baryta in increasing order.

    A coating defect appears on the left (soft grade) print which is not untypical of coating on Watercolor or Baryta.

    I am posting two samples of a soft and hard grade on Watercolor. This particular paper has a rich surface similar to canvas, so the pattern you see is not a defect, but rather an artifact of the scanning process.

    They were both exposed for 10" and developed in Dektol 1:3 for 1', followed by stop and fix. The fix was an acid hardening fix. I have used a variety of developer for processing this emulsion including the M&P Amidol developer. All work quite well.

    PE
    Attached Thumbnails Attached Thumbnails print contrast soft.jpg   print contrast hard.jpg  

  2. #2
    Sean's Avatar
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    very cool Ron. I've enjoyed following your progress

  3. #3
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    Very cool.

  4. #4
    Photo Engineer's Avatar
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    Thanks, more coming.

    PE

  5. #5

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    I'm still holding my breath for Lodima; but this may be an attractive alternative. Looking forward to seeing more results.
    van Huyck Photo
    "Progress is only a direction, and it's often the wrong direction"

  6. #6
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    This is very interesting news. I've been following your posts on emulsions and will follow them even more closely now.

    cheers

  7. #7
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    Quote Originally Posted by John Bartley View Post
    This is very interesting news. I've been following your posts on emulsions and will follow them even more closely now.

    cheers
    Yup, this one got my full attention.

  8. #8

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    The progess you've made in the past year is very encouraging. I might be coating my own papers with custom emulsions some day.

    K.

  9. #9
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    P.E.

    1) this is fascinating; and
    2) where did you get the picture of my Dad in his late 20s (maybe it's the "Kodak look").

    Matt

  10. #10
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    Well there you go. PE has done it in a method traditional of early scientists. A very high praise to you, and the best of luck and success in your progress.

    Regards,

    Curt

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