Finding starting point developing time without data

Discussion in 'B&W: Film, Paper, Chemistry' started by BetterSense, Aug 11, 2009.

  1. BetterSense

    BetterSense Member

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    I recently switched to d23 and found it hard to find development data compared to d76. I actually went to the MDC and made a spreadsheet comparing average ratio of d23 times to d76 times so I would have some idea where to start on films like Acros that have no data available (I found that about 75% of the d76 1+1 time was average for a d23 time). Even Kodak datasheets don't give d23 times.

    I don't mean to call out Photo engineer specifically but I've never heard of such a test. How is it conducted?
     
  2. Laurent

    Laurent Subscriber

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    Hi,

    I hope what I'll say makes sense, otherwise I'll just hide for a while ;-)

    IIRC, the dip test is simply to dip a piece of film (leader from a 35mm cartridge for example) in the developer, and see how long it takes to get the max. black. This should at least give you a basic idea of the time needed.

    Hope this helps
    Laurent
     
  3. Ian Grant

    Ian Grant Subscriber

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    At one time D23 times were listed being the same as for D76, so that's your starting point.

    Ian
     
  4. aleckurgan

    aleckurgan Member

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    Hello.
    There's an old technique (could be the same dip test mentioned by PE):
    - take a small strip of film you want to test;
    - put it halfway in the developer and start the clock;
    - stop the clock when the part in the developer reaches the same colour as the part outside (it is lighter at first and then begins to darken);
    - multiply the time you measured in seconds by 17,5 and divide by 60 to get your development time in minutes.
    For example: measured time 25 sec * 17,5 = 437.5 sec / 60 = 7.3 min development time. This should give you a good starting point.
    It can be also quite useful for people who like to experiment with different dilutions.
     
  5. jnanian

    jnanian Advertiser Advertiser

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    bettersense

    you might also consider getting a darkgreen safelight
    and learning how to DBI ( develop by inspection )
    i often do this with sheet film, and have done it a few times
    with 125 and 120 ... it is not to hard to learn this technique,
    and may be very helpful.

    there is a great article here:

    http://www.michaelandpaula.com/mp/devinsp.html


    thanks for writing about " the test" aleckurgan !
    i had never seen that.
    lights on or off ?
    ( sorry i am not a master of the obvious sometimes! )

    john
     
  6. Photo Engineer

    Photo Engineer Subscriber

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    Laurent's post says it all.

    PE
     
  7. aleckurgan

    aleckurgan Member

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    Of course on! :smile: Otherwise you won't see the difference between wet and dry parts.
     
  8. pcyco

    pcyco Member

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    hallo

    my scetchbook says acros with d-23 1+1 for 15 minutes gives a good result (rollfilm)

    are you using d-23 oneshot or more than one time?
     
  9. Photo Engineer

    Photo Engineer Subscriber

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    Sorry, but this test does not make sense to me.

    The part outside the developer will not darken or change at all, and the part inside the developer will darken. The part outside the developer is not even developing, it is raw emulsion.

    Or did I misunderstand something?

    PE
     
  10. BetterSense

    BetterSense Member

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    I usually use it replenished, but I have another batch for use with dilutions or films that stain my replenished developer (foma/edu.ultra). Thanks for the data. Is that at box speed? I'm going on a trip soon and will probably shoot up some acros.
     
  11. pcyco

    pcyco Member

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    hallo

    yes, box speed, in a yasica d when i remember right.
     
  12. Igor Savchenko

    Igor Savchenko Member

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    what's your agitation technique, please?
     
  13. Igor Savchenko

    Igor Savchenko Member

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    I guess the method is valid for a box speed. And what is the agitation technique?
     
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  15. BetterSense

    BetterSense Member

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    3 quick inversions every minute
     
  16. Photo Engineer

    Photo Engineer Subscriber

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    Guys;

    Please note my previous post. My take on the est by ALECKURGAN is that the test does not make sense to me. Please read it and my comments carefully before you try it.

    PE
     
  17. Ronald Moravec

    Ronald Moravec Member

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    This is all insane except what photo engineer wrote. You got a film and a developer. Find a standard test subject, I use a doll with white blouse and black pleated skirt, grey scale and grey board. I illuminate with studio strobes so the target is the same reguardless of time or seasom. Expose so you get details in the blacks and run a test development. With some experience, you can look at the results and see if they will print. When you get close, make a real print, ascess it, tweek the time, retest. I have done this so long that 2 or three times will yield a good or perfect time.

    How do they come out compared to manufactures times? Kodak times are very close. Ilford times with Ilford film is just as good. Ilford film with non Ilford developers are long, on purpose? MDC are totally screwed up. I can pull better numbers from the air.

    I have had good luck with comparing times with one film and developer and extrapolating to another combo if only one variable is changed.

    But nothing is as good as is my standard target and , a trial time , and making a print. We can`t be lazy.
    Shooting some pics and then coming back to check how long to develope simply does not make it. There are no shortcuts unless you are an expert with a densitometer.

    If you want to use 1/2 box speed, cut the time 20% It always worked for me. 2x box speed, well you will lose shadow detail unless something is a miss in the system and box speed was wrong for you like a slow shutter. I do not do this ever. I get a faster film.
     
  18. clayne

    clayne Member

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    Some of you guys who refuse to "push" film or treat it like religious sin crack me up.

    You don't always need every single last piece of shadow detail, ya know?
     
  19. pcyco

    pcyco Member

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    hallo

    my agiation method is: the first minute full agiation, and then all 30 seconds 3 or 4 agiations
     
  20. psvensson

    psvensson Member

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    Shoot a test roll of an evenly lit, featureless wall. Expose alternatingly at -4 stops from the meter reading and at +3, for a seven-stop difference. Cut a piece from this roll, long enough that you get at least one plus-exposed and one minus-exposed frame. Develop, using your best guess for a time.

    When the snippet is dry, measure the relative densities of the two frames by putting it on a light table (or other evenly underlit surface) and putting a light meter with the sensor in contact with the film, and taking a reading. I made a small snoot for the sensor on my Sekonic L308B meter. Otherwise, you can use a camera's built-in meter, if you create a mask with a cutout for the film, then place it over the lens.

    The difference between meter readings from the two frames should be 4 stops*. If it's more, develop another snippet at a shorter development time and measure again. If it's less than 4 stops, increase your time.

    This is the equivalent of using a densitometer. It's more accurate and faster than lighting a full-scale subject and printing the resulting negative.

    Note that the -4 exposure should show a bit more than shadow of density compared to no exposure (it should actually be 1/3 stop over base density, but that can be tough to measure). If there's no density at all in the -4 frame, you may need to lower your EI and shoot another roll. However, if there's a lack of density and the contrast range is low, first increase your development time and process another snippet - it may be that there's insufficient -4 density because of gross underdevelopment.

    *4 stops times 0.3 log = density of 1.2, nominally appropriate for diffuser enlargers. I've started developing to a range of 1.1 instead, finding that my current papers don't need that much contrast. That corresponds to range of 3 2/3 stops.
     
  21. 2F/2F

    2F/2F Member

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    IMO, you should fill a roll with bracketed exposures of a MacBeth chart or other "official" grey scale, and do clip tests to determine the development time.

    If you don't have one, buy one. If you can't afford one, rent one or borrow one. It is perhaps the most useful photographic testing tool you'll ever own.

    Take notes of each exposure. Set your meter at box speed.

    If using an incident meter, expose like it sez. If using a reflected meter, take a reading off of a grey card and open up 1/2 stop from what the meter sez.

    Take your first exposure two stops more open than what the meter sez. Bracket up (in 1/2 or 1/3 stops, depending on what degree of precision your camera's aperture ring allows) until you are two stops more closed than the meter sez. Take some blank pix (lens cap on).

    Do the same thing over again until the roll is finished. (If you are using 120, just shoot multiple rolls.)

    When you go to develop, do clip tests, starting at whatever the recommended time is. If you have no idea, try something in the 8 - 10 minute range with standard dilutions (i.e. straight or 1:1). Try to cut the film where the blank shots are. If you don't get the cut right on, don't worry. As long as you are somewhat close, it will just be an extremely over- or under exposed frame that you cut. Try using a pre-cut length of something (e.g. string) to help you gauge the proper distance for the cut.

    Then test development times until the MacBeth chart prints the way you want it to print on your targeted paper and grade. Use your optimally exposed contact sheets (film edges should be black or right near it) as a guide to choose which negs look the best to print.

    Whichever negative you printed from that gave you the most accurate representation of the grey scale on the MacBeth, count how many shots away from the meter-recommended shot it was. In the future, adjust your EI accordingly. Whichever development time you used for that shot, that is your normal time.

    It's one way of doing it. It is pretty simple, IMO. You just need to get that chart.
     
  22. 2F/2F

    2F/2F Member

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    P.S. If you just don't want to or can't afford the chart, you can use a grey card. To do this, the shooting procedure is a bit different. You must actually tonally "place" the card at various spots on the grey scale via exposure. IMO, the chart is much easier, as you get the whole grey scale in one shot.
     
  23. eclarke

    eclarke Member

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    I'm more obsessed with highlight detail:smile:..Evan Clarke
     
  24. Ian Grant

    Ian Grant Subscriber

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    Actually you missed something Ron :D

    This is a very old and extremely well known test which has largely gone out of use since WWII.

    The Watkins test dates back to 1893, and essentially every developing agent has a factor in the case of D31 & Metol it's 17.

    It's probably no worse than developing almost to completion to find the minimum time to give a full D-max, as that will almost certainly give over developed contrasty negatives.

    Ian
     
  25. Photo Engineer

    Photo Engineer Subscriber

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    Ian;

    When you start with the strip, it is entirely the same density. Dip one end in developer, and it begins to darken (and lighten) at the same time. It darkens due to development and lightens in some cases due to loss of acutance and trimmer dyes which differ from film to film.

    You end up with a light end and a dark end. The only time that they can match is at the very instant the test starts. And, the rate of change will vary from film to film more due to the dyes which were not present to any extent before WWII.

    Therefore, there are a number of problems with this test, as written above.

    PE
     
  26. Sirius Glass

    Sirius Glass Subscriber

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    Perhaps Ian can rewrite the procedure so that it can be clearly understood. I have read and studied it a number of times and it is as clear as well used Pyro stain.

    Steve