DK-50 Dilutions

DK-50 Dilutions

  1. voceumana

    voceumana Member

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    voceumana submitted a new resource:

    DK-50 Dilutions - DK-50 Dilutions

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    Last edited by a moderator: Feb 6, 2016
  2. Christopher Walrath

    Christopher Walrath Member

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    My old dtat guide has a time/temp chart that indicates 6.5-7 minutes at 68F. Does not specify any particular film but it's a starting point.
     
  3. jnanian

    jnanian Advertiser Advertiser

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    hi voceumana

    not sure if you searched here for dk50 threads
    but http://www.apug.org/forums/forum37/10972-dk-50-its-use.html
    might be helpful ...

    i have never heard of diluting it as you suggest. the best use of dk50 is straight, with sheet film.
    i used it for a long time as i was a lab-person for a portrait photographer trained in the 20s/30s ...
    i processed armloads of 5x7 sheets of tri x and tri x ortho, straight never dilute developer in deep tanks.
    the trick with a lot of deep tank developers is they need to be mellowed to work best.
    that means not to dilute them, but to process a bunch of film in them so they get oxidized
    and then use it. i replenished ours for a certain number of films through it, and then when i mixed fresh
    i left about 1/3 a tank of spent developer to mellow the new, so it would work right ...
    besides 5x7 sheets, i processed my own 4x5 (hangers) and 35mm ( on a bent coathanger ) in the same tanks
    and got very good results. grainless, nice contrast ...

    i wish i could be of better help for dilute dk50 ...
    digitaltruth doesn't even have times for this developer, dilute ...

    if you have a green safelight, you could always develop by inspection
    and get a better idea on what your times should be.
    there is a very good article here .

    good luck!
     
  4. jnanian

    jnanian Advertiser Advertiser

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    that is for dilute ? or straight ?
    i used to process sheets of tri x around that time/temp
    and i wasn't using dilute developer ...
     
  5. Ian Grant

    Ian Grant Subscriber

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    Geoffrey Crawley discussed using dilute DK50 in a series of eight articles on Developers in Dec/Jan 1960/61 in the British Journal of Photography.

    The data was included in subsequent BJP Almanacs /Annuals. You need to make up an additional solution of approx 8.3% Sodium Metaborate (Kodalk). This is said to give "a useful balance of natural acutance, gradation and speed qualities with controlled contrast rise" Effectively this is 1+4 with additional alkali.

    Dilute DK-50

    Part A
    Stock DK-50 (full strength)

    Part B
    Sodium Metaborate (Kodalk) 83.3gms (1oz)
    Boiled Water to 1 litre (12oz)

    To use:

    2 Parts A - DK50
    1 Part B
    7 parts water

    Development times: FP4 8-9 mins @ 20°C, Pan-X 10-12 mins, Tri-X 13 mins.

    Hope that helps

    Ian
     
  6. Christopher Walrath

    Christopher Walrath Member

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    The dataguide I have said straight solution. I personally don't use. Just relaying info.
     
  7. voceumana

    voceumana Member

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    Anchell/Troop's Film Developing Cookbook mentions DK-50 1:3 as well as BJ Dilute DK-50, and indicates it gives close to a straight line curve without "blowing out the highlights" and suggests the higher dilution for modern films (possibly even 1:6 for TMax if I remember right). But alas, no suggestions on starting times. There outta be a law...when a book recommends a developer it should have to say how to use it, at least as a starting point! DK-50 is recommended for subjects of limited contrast range such as studio work.

    This is the reason for my interest in the developer at this dilution.

    Ian: Thank you for the BJ recommended times--it gives me some starting points.

    Charlie Strack
     
  8. Ian Grant

    Ian Grant Subscriber

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    Charlie, the FDC dilution is essentially the same 1+4, Troop has used a weaker solution of Metaborate, also he's taken Crawley's figure of 1oz Metaborate in 12oz water (83.3gm/litre) and and substituted 50gms Metaborate/litre. Perhaps you took the 1+3 figure from the 1+1+3 Troop gives as the working solution.

    Ian
     
  9. lamda

    lamda Member

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    A Kodak data sheet (F-4017) from 2007 for Tri-X 320 and 400 shows some times for DK-50 1:1.
     
  10. Ian Grant

    Ian Grant Subscriber

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    The BJP - Crawley - Dilute DK50 uses additional Metaborate to maintain it's activity at 1+4 and keep development times within reasonable parameters. Crawley published this version of the formula Jan 27th 1961 in the BJP, the Metaborate solution is given as 10z in 12oz water, (83.3g/litre), same as the 1976 BJP Annual version I gave above.

    Ian
     
  11. voceumana

    voceumana Member

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    Ian,

    Understood. I think I got the 1:3 ratio (for standard DK-50) from a different thread on DK-50. I'll try the BJ dilution with the additional metaborate.

    Thank you,
    Charlie Strack
     
  12. RidingWaves

    RidingWaves Member

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    Yes, please tell how it works. I have a bunch of old bags of DK-50 that never seem to make it to the Deep Tank stage.
     
  13. Christopher Walrath

    Christopher Walrath Member

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    This is a reply I gave to a DK50 thread but I thought I would centralize it here in this article.

    This is the recipe for the Kodak DK50 Film Developer as well as the DK50-R Replenisher according to an old Amphoto B&W Processing Databook.




    DK50

    Popular tank developer for commercial and portrait photography.

    Water (52C or 125F)
    500.0 cc
    Kodak Elon Dev Agent (Metol)
    2.5 grams
    Sodium Slfite, dessicated
    30.0 grams
    Hydroquinone
    2.5 grams
    Kodalk (Sodium Metaborate)
    10.0 grams
    Potassium Bromide
    0.5 grams
    Add cold water to make 1 litre

    Dissolve chemicals in the order given.
    Do not dilute for tank development. Develop for 5-10 minutes at 20C (68F). (Note: time scale indicates 5'00" at 75F/ 6'15" at 70F/ 7'00" at 68F/ 8'00" at 65F/ 10'00" at 60F) Decrease time by 1/5th for tray development.


    DK50-R Replenisher

    Water (52C or 125F)
    750.0 cc
    Kodak Elon Dev Agent (Metol)
    5.0 grams
    Sodium Sulfite
    30.0 grams
    Hydroquinone
    10.0 grams
    Kodalk (Sodium Metaborate)
    40.0 grams
    Add cold water to make 1.0 litre.

    Dissolve chemicals in the order given.
    The replenisher should be diluted to the same ratio as the developer it replenishes. Add to developer as needed to maintain the level of the developer. If the density of the negative is not maintained, discard some of the developer from the tank at intervals and replace with replenisher.