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  1. #191

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    Quote Originally Posted by Bill Burk View Post
    The lesson to learn. As ic-racer said: It is possible to achieve less than rated speed. You can develop long enough for the contrast to come up and fit the contrast of the ASA triangle while at the same time the entire curve, similar to the full speed curve, can land to the right...
    Exactly. So instead of testing with "effective" agitation, why not make a test with a single sheet and intermittent agitation? Agitate for the first few seconds of each minute by flipping the sheet over a few times (after initial agitation of say 30 seconds). You would likely have to increase development time to get the contrast of the ASA triangle, and your speed might increase. At worst your speed will stay the same.

    Anyway, sorry if this is sounding argumentative. I'll back off now.

    As for making pictures, I assume we're all doing that - and printing too.

  2. #192
    Bill Burk's Avatar
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    Made two changes: Improved agitation, reduced time.

    Conclusion from this test: One sheet developed alone by tray builds density much faster than stacks of six sheets.
    Inconclusive from this test: Speed cannot be determined due to fog.

    Two changes for next test: Reduce Fog. Reduce time further.

    I normally see 0.05 fog. This case I have 0.24 fog. I blame IR viewer, ATN Viper. I kept my eye on the clock instead of the sheet. With my head raised, and with chrome faceplate on the clock shining bright, the eyepiece was brighter than usual and a gap between eyepiece and my eye could have allowed green light from the eyepiece to refelect off my eyeball and strike the film during processing.

    ---
    TMY-2 D-76 1:1 68-degrees F 11 minutes Tray single sheet 12 rocks/min - B+F 0.24
    ---
    Step,Density
    01,3.44
    02,3.31
    03,3.21
    04,3.11
    05,2.98
    06,2.86
    07,2.71
    08,2.56
    09,2.41
    10,2.26
    11,2.09
    12,1.91
    13,1.71
    14,1.53
    15,1.34
    16,1.15
    17,0.94
    18,0.77
    19,0.63
    20,0.48
    21,0.32
    22,0.19
    23,0.10
    24,0.04
    25,0.02

    ---
    p.s. Enlarger ----> Sensitometer curve is similar. Curve was displaced about one stop. Next test I will put Enlarger exposure on same piece of film as Sensitometer exposure. And I will reduce EV to 0

  3. #193
    Bill Burk's Avatar
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    Well I WAS going to shoot that film next weekend...

    Did some tests instead. Film needs to dry before I can read it. Was about to get a hairdryer out to speed up the drying process... Then I realized the grid of metal rods with clothespins that I have the wet film hanging from is a FILM DRYER. All I have to do is plug it in and turn it on... Never thought of that.

    Michael R 1974,

    My goal was to see if I could get full film speed by changing agitation from poor to optimal. Since Todd-Zakia says 12 rocks a minute is optimal, I am using that as a standard.

    Development one sheet at a time is dramatically faster than developing stacks of six sheets. My first two tests were off the charts, I got CI 1.0 in 9 minutes. Today's development times are 4:30 and 6:30. Both look like they are ballpark normal. At least I will have some reasonable Time/CI points.

    I've been doing these tests with a 21-step grayscale, and a 2-stop (0.6) ND filter. A 31 step grayscale would make this work much easier.

    I am putting four tests on each piece of film: Two with the EG&G and two with the Enlarger at EV-0 for 5 seconds. Since the tests are all on one piece of film, I hope to show the curves are similar. So you will see that using an enlarger as a test strip maker, as PE said, is perfectly capable.

  4. #194
    ic-racer's Avatar
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    Quote Originally Posted by Bill Burk View Post

    I've been doing these tests with a 21-step grayscale, and a 2-stop (0.6) ND filter. A 31 step grayscale would make this work much easier.
    Reminds me of the guy that has his pizza cut into 6 pieces because he said he can't eat 8 pieces.
    I take it you want to show the shoulder. I think the Stouffer 31 step has the same OD range as your 21, but with 1/3 stop increments. If you go with the 41 step wedge you can get up to total OD in the 3.0 range. I can say from my experience that I get big changes in the high densities with different processing conditions, and not so much change in the shape or position of the low end, so knowing what is going on with those high densities can be nice.
    Last edited by ic-racer; 07-26-2012 at 03:16 PM. Click to view previous post history.

  5. #195
    Bill Burk's Avatar
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    Quote Originally Posted by ic-racer View Post
    Reminds me of the guy that has his pizza cut into 6 pieces because he said he can't eat 8 pieces.
    Funny.

    No I don't want 31 steps if it means third-stops. I really just want more density to catch the toe.

  6. #196
    Bill Burk's Avatar
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    AAAAAAHHHHRRRRGGGHHHH

    Guess why the first two sheets were off-the-charts in density?

    I'll give you a clue. Usually this developer is mixed from stock at 1:2

  7. #197

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    Quote Originally Posted by Bill Burk View Post
    No I don't I really just want more density to catch the toe.
    I added a short strip of half inch aluminized mylar tape on one end of my stouffer tablet so I had enough density that I always got a good reading for b+f.

  8. #198
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    Correction required to Post 192...

    Quote Originally Posted by Bill Burk View Post
    Made two changes: Improved agitation, reduced time.

    Conclusion from this test: One sheet developed alone by tray builds density much faster than stacks of six sheets.

    I normally see 0.05 fog. This case I have 0.24 fog.

    ---
    TMY-2 D-76 1:1 68-degrees F 11 minutes Tray single sheet 12 rocks/min - B+F 0.24
    ---
    There were three changes not two: Changed developer

    Conclusion: Developing film in Dektol, normally used for prints, builds density much faster than D-76, and it increases fog.
    ---
    TMY-2 Dektol 1:1 68-degrees-F for 11 minutes Tray single sheet 12 rocks/min - B+F 0.24
    ---

    Changes for next time: When the kids label the bottles, have them use color pencil or crayon instead of washable markers.

  9. #199
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    Calibration of Sensitometers. A Kodak patent from 1996.

    http://www.patentlens.net/imageserver/getimage/US_5543883.pdf?id=8771083&page=all



 

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