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Thread: Rotary Processing Rodinal

  1. #1
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    Rotary Processing Rodinal

    Now that I think Rodinal is available I am getting back to some experiments with rotary processing in Rodinal. The ideas of edge effects and agitation with Rodinal have been discussed in length, however, I have not seen negatives for myself to support any claims either way.

    My setup involves a Jobo processor with temp control and lift and a Jobo tempering box.

    I created a spread sheet that does the calculations for me. Basically the input data is

    nominal Rodinal dilution: (ie 1:100)
    ml of Rodinal per roll: (ie 10)
    number of rolls: (ie 4)
    Volume for processor for those rolls: (ie 470cc)
    Time: (ie 12 min)

    The output from the spread sheet includes:

    Actual total volume of chemistry: (ie 3290cc)
    Actual volume of Rodinal: (ie 40cc)
    Actual dilution: (ie 1:98)
    Number of bottles of developer: (ie 7)
    Timing interval: (ie 1min 47sec)
    Complete list of change times:

    The spread sheet is pretty sophistocated in that it figures out how many changes of chemistry are required so that a total volume of dilute developer is seen by the film. It rounds it out to an exact volume based on the Jobo tank information on rotary tank capacity. Due to this rounding the final dilution is not quite 1:100, but the spread sheet lets you know what the exact dilution wound up being.

    The spread sheet also does the timing math so there is a printout of the times as they would come up on the Graylab timer so I know when to dump each segment of developer.

    I am just starting the process of testing the films but so far my initial feelings are
    1) Rodinal gives good even development with rotary procesisng
    2) The images are sharper than T-max developer
    3) There is more grain than T-max developer.

    Based on these positive results I am going to continue testing with pictures and Wejex strips.

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    Re: Rotary Processing Rodinal

    I will be following your progress. Rinses, stop, and fixer details will be useful to know too. Are you using any "special" water?

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    Re: Rotary Processing Rodinal

    Quote Originally Posted by Clueless Winddancing View Post
    I will be following your progress. Rinses, stop, and fixer details will be useful to know too. Are you using any "special" water?
    Back in the 80s I used to dilute all my 'one shot' developers with distilled water. I got lazy and for the last 10 years have been using tap water. Probably depends on where one lives and the quality of the tap water.

    I used Kodak 'indicator' stop bath for 20 years then found some bluish stains in water dripping from some processed prints and switched to glacial acetic acid. I wear the respirator mask I use for spray painting when opening the concentrated bottle and make up 5 gal. of less concentrated solution which I dilute just before using.

    For fixer I have been using Ilford Hypam or Rapid fixer 1:4 (no hardener). I use 5 or 6 minutes. I honestly don't know how long to use this stuff but after some 'double the clearing time' tests I did a few years ago I settled for 5 or 6 minutes.

    Due to my irregular schedule of being in the darkroom, everything needs to be in concentrated 'long lasting' form that is diluted just prior to use. I have lots of pipets, medical hypodermics of various sizes and small graduates for measuring the small quantities.

    I started rotary processing B&W in 1987 and have been perfecting and upgrading the system since then. I know that some developer/film combinations are no good and if one uses them they are just beating thier head against the wall to persist. One can talk all they want about various reels (metal/plastic) and rotation speeds and directions, however, certain film/developer combinations are very happy irrespective of all this. Tmax/Tmax is a good example. I can't say the t-structure or tonal scale is why I use it. I have used this combo since 1980s because it gives even development even at the edges of 120 film in the Jobo plastic reels with rotary processing.

    I have a renewed interest in Rodinal lately because I think it also is a 'good guy' when it comes to rotary processing.

    Why change? Why look for new solutions to old problems? Because I honestly don't know how much longer the T-max developer and or film will be available.

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    Re: Rotary Processing Rodinal

    Here is a screen shot of the Rodinal worksheet. It does all the calculations so I can concentrate on the 'controversial' variables like how many ml of solution required per roll and which dilution is 'best.'
    Attached Thumbnails Attached Thumbnails rodinal worksheet.jpg  

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    Re: Rotary Processing Rodinal

    Here are some film curves showing TMY's response to Rodinal and T-max developers. Cruious how the Rodinal curve takes a downward dip with the highlights while the T-max can take an upward dip (though it shows up a little farther up the shoulder than indicated here).

    BTW I use a Wejex sensitometer (that I restored and converted to close to 5500K with some filters) and a Tobias densitometer.

    I bought these items recently for one reason: uncertainty in film availability.

    It works like this
    1) spend 20 or so years getting good photographs and finding good developer/film/development time/exposure data through trial and error.
    2) worry about one's favorite materials becoming extinct
    3) buy sensitometer and densitometer and 'reverse engineer' curves from favorite combinations
    4) use this information to test new materials so one does not have to spend another 20 years of trial and error with the new materials

    So, here is an example of comparing a 'known' to an 'unknown'

    I have used the T-max developer at 5.5 to 6 minutes for many years and it works well with my enlarger/enlarging lens/printing paper combination.

    My first test with the Rodinal and a time I guessed at (11 minutes) shows less contrast than what I am used to. So i'll bump up the time a little for the next test.

    (The X-axis says "Wejex Exposure" but it is supposed to be the inverse of that. The X-axis numbers are the transmission densities of the Wejex's step wege. The actual 'exposure' would be the inverse of this)
    Attached Thumbnails Attached Thumbnails rodinal vs tmax deveoper.jpeg  

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    Re: Rotary Processing Rodinal

    Experimentation held up a while as I ran out of my Rodinal. I am waiting for two large bottles from Freestyle.

    When I had started thinking about using the Rodinal again I thought I needed to go back to a conventional grain film. I am finding that the T-max films seem to work well (that is they have the added sharpness I am looking for). This is good because I already have all my exposure data for T-max films.

    Another 'introductory' point is that I have gotten so used to using the 'sharpen' image transformation in Photoshop to make up for the crummy lens on my digital point and shoot that I wanted to use the 'edge effect' of Rodinal with my Horseman lenses to do the same thing. Years ago while at the NIH I wrote a image processing program (based somewhat on the pre-existing "NIH Image" (now antique) Macintosh program). I wrote the code for the sharpen and blur filters and they act just like the chemical edge effects caused by Rodinal.

    Having been a Rolleiflex user for 20 or so years I am used to the contrast and sharpness of the Zeiss lenses. Now that I have a Horseman VH-R with 8 of the original lenes I can tell that they do not have the same contrast or sharpness. Is this bad? NO! These are awesome lenses, I just want to fine tune my film processing to get more illusion of sharpness.

    I am very realistic about this. There is no way I expect my 90mm Horseman lens with it's 150mm coverage to be as sharp as my 80mm Zeiss Planar. Because I am shooting 6x9, it does not have to be as sharp because for the same size print, the magnification is less.

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    Jobo tempering box

    Here is the Jobo tempering box in action. The tempering box holds all the dilute developer. Depending on the concentration and the number of rolls to process there would be from 4 to 10 bottles or changes of developer.

    The Rodinal is carefully measured into each bottle with the correct amount of tap water.

    The Jobo processor holds the rest of the chemistry in its 6 bottles as follows:

    Bottle 1: Developer (not used when processing Rodinal)
    Bottle 2: Acetic acid
    Bottle 3: Ammonia thiosulfate fixer
    Bottle 4: Water (prewash for the Permawash)
    Bottle 5: Permawash
    Bottle 6: one liter of water to flush the lift
    Attached Thumbnails Attached Thumbnails Tempering box and processor.JPG   Measuring rodinal 2.JPG  

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    Wejex

    Originally I was looking for an old beat up sensitometer so that I could modify it to accept a xenon flash and some ND filters.

    The Wejex that I wound up getting from e-bay was actually quite nice. Too nice to tear apart and modify. Inside the box the mechanism was perfect and had no signs of being tampered.
    I took it all apart and cleaned and checked everything. While apart I was able to measure each step of the step-wedge with my densitometer. This gave me exact numbers for my x-axis of the H-D curves. This also was nice because I used the same densitometer I will be using to check the film.

    My Wejex came with a filter drawer, and I put an 80A filter in there.

    On the bottom there are two sockets for the probes of an AC voltmeter to kind of calibrate the light intensity with the built in variable resistor. Before doing test strips I check the voltage to see if there is any drift. I have it set at about 5.5 AC volts. Obviously aging changes in the bulb are not accounted for. (I'm not trying to duplicate ISO standard here, I'm more interested in the slope of the H-D curves rather than the displacement of the curves along the X-axis.)
    Attached Thumbnails Attached Thumbnails Wejex and tobias600.JPG   Wejex wedge600.JPG   wejex filter drawer600.JPG  

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    Sensitometers

    Incidentally, when looking for a sensitometer I inquired about the Agfa sensitometer (http://www.agfa.com/docs/sp/aerial/a...4-06-15_en.pdf) and got this response:

    "The price of the Avisense 2000 is $26,801.90 for the basic sensitometer including one filter insert. With this filter insert the daylight flash of 1/1000 sec is generating a light quantum of 1 Lxs or 1mcs.
    Additional filters are $219.29 ea."

    Wow!

    Anyway I paid about $100 for my Wejex on ebay.

  10. #10
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    Re: Rotary Processing Rodinal

    I was able to process 6 rolls of 120 in dilute Rodinal (about 98:1) in the 1500 series tanks. All the film came out OK except one roll which had greater density on one edge. Unfortunatly I don't know where in the tank this roll had been placed (ie near the filling end, or near the middle, etc). I was able to make a good print from this roll but it required burning in the right hand edge of the print. Since the other rolls were OK I will continue onward. I have not really sat down with the loupe and the negatives to check for sarpness between the tmy in Rodinal vs the tmy in T-max developer.

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