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  1. #1

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    Reversal baths for black & white film

    Various references to reversal processing such as the ILFORD pdf and the chapter of 'The Darkroom Cookbook, 3rd edition' give a re-exposure to light as the reversal step. However, the pdf for the Kodak T-Max 100 reversal kit seems to indicate that no additional re-exposure is required.

    I presume there is a reason why DIY mix reversal baths have not been suggested.

    Tom.

  2. #2
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    diy reversal usually is based on a tin salt based solution, to chemically fog the undeveloped silver.

    It is not that environmentally nice, and it also has a tendency to allow things to 'grow' in the stock solution that makes it a hassle to use, as I recall.

    Below are a collection of notes I have gathered a few years ago from rec.photo.darkroom when it was active, and beore a lot of contributors moved to places like this. I myself have not tested all of the information presented below:

    Here's the steps from a Kodak publication for reversal processing
    (1973): (supplied with Kodak Reversal Processing Kit)
    1 First developer D-67 6-8 Mins. (68 F)
    2 Rinse Water 2-5
    3. Bleach Bleaching Bath R-9 1
    4 Clear Clearing Bath CB-1 2
    5. Redevelopment Fogging Developer FD-72 8
    6 Rinse Water or SB-1 Stop Bath 1
    7. Fix Kodak F-5 or F-6 5
    8. Wash Water 2
    And here's the formulas:
    D-67
    Water at 125 F 500ml
    Elon 2.0 gr
    Sodium Sulfite (Anhydr) 50.0 gr
    Hydroquinone 8.0 gr
    Sodium Carbonate (mono) 52.5 gr
    Potassium Bromide (anhydr) 5.0 gr
    Sodium Thiocyanate (liquid) 51% solution 3 ml
    Water to 1.0 l
    OR
    D-19 1.0 liter
    Sodium Thiocyanate (liquid) 51% solution 3 ml
    Replenisher D-67R
    Water (125 F) 750 ml
    Elon 2.0 gr
    Sodium Sulfite (anhydr) 90.0 gr
    Hydroquinone 8.0 gr
    Sodium Carbonate (mono) 52.5 gr
    Sodium Thiocyanate (liquid) 51% Sol. 7.5 ml
    Water to l.0 l
    FD-72
    Part A EASTMAN Sodium Dithionite (sodium 5.0 gr (hydrosulfite (Cat No. P533))
    Part B
    Water 500 ml
    Balanced Alkali 10.0 gr
    EASTMAN L-(+)-Cysteine 0.3 gr Hydrochloride (Cat No. 2367)
    Water to 1.0 liter??? Not sure here
    Disolve 5 grams of Part A in 1 liter of Part B not more
    than 2 hours before use. Discard after one use.
    Bleach Bath R-9
    Water 1.0 liter
    Potassium Dichromate 9.5 gr (anhydr)
    Sulfuric Acid (concentrated) 12.0 ml CAUTION: Add slowly, stirring constantly.
    Clearing Bath CB-1
    Water 1.0 liter
    Sodium Sulfite (anhydr.) 90.0 gr
    SB-1, F-5 and F-6 are well known formulas.
    The films listed are the discontinued Direct Positive, Panatomic-X,
    also discontinued, Plus-x and Tri-x Reversal films, discontinued as well.
    And 4-X reversal 7277, something unknown to me.
    I'll bet the EASTMAN chemicals, which were some sort of special bulk
    order at the time are no longer available from Kodak.

    A long, long time ago I used Pan-X in 35mm to make direct positives, then
    enlarged onto Kodalith processed for continuous tone and used these to make
    T-shirts using Inko Dye (kind of like making a cyanotype on cloth, except
    you had the option of different colors.) I don't think there 's any reason
    to believe that the modern (or is that post-modern?) equivalent won't work.
    TMX processed in either the Kodak or other reversal chemistry can produce an
    excellent negative. Several years ago I made quite a few 8x10 enlargements
    using both Kodak's chemistry (tried early kits with dichromate bleach and
    later ones with the permanganate bleach) Finally
    I quit using their re-exposing developer and re-exposed to light for the
    reversal. Had no further problems.

    The major problem I had with Kodak's kits was the cost. At about $30 (then)
    per kit which would process 15 (I think) sheets, plus the cost of the
    film, it was easy to spend a lot of money quickly. As a grad student the
    costs were prohibitive. Another concern is exposure, since you need to fill
    the drum for maximum economy, it's not always easy to make test strips and
    see what they look like. But if you're doing a lot of work you'll get the
    exposure figured out fairly quickly.
    Hal Faulkner

    Hi all,
    Reversal is easy to do, making a neg for printing out on self masking
    materials like Pt/pd or kalitypes is not. One old source says:
    "The negative which prints perfectly in platinum is one which has been
    exposed for the shadows and has been developed until the surface of the
    plate appears to have lost its image."
    Luckily I made some by accident but not by the simple way copying neg ->
    interpos -> neg -> print. I tried various films for reversal, these 1982
    notes show some of the problems and results:
    Verichrome pan 125 - Good gradation & tone, bad reticulation in mid
    tones, chewedl way, interesting graphic effects. Process: Rodinal (Agfa)
    1:15 10' with hypo 9ml, bleach std, redev rodinal 1:20
    Plus X prof 125 - Good gradation, slightly overposed suggest ½ stop,
    sharper, more detailed, slightly grainy- worse than FP4, 10x grain crisper,
    watch hardening, tends to scratch. Process: Rodinal 1:15 12' with hypo 6ml,
    redev rodinal 1:12.5 2films. Pre-bath hardener: formalin 2%.
    FP4 125 - Slightly contrasty, highlight thickness, need for bleach
    subsequently, tends to frill but hardening may fix it.
    PX - Thin neg and dense highlights i.e overdeveloped, gradation not bad.
    Process: Bromophen 1:2 5' with hypo 6ml, ½bleach
    FP4 - Dmax thin, good gradation. Process: Rodinal 1:15 with hypo 21ml,
    bleach ½std, redev Ultrafin 1:10 ( a Tetanal product), acid hardener, no
    pre-bath. GOOD
    PXP - Development contd while bleaching, some remains at re-exposure
    stage, took it out of bleach part way through for inspection, lightly
    fogged. This was then bleached after completion so overall density reduced.
    Appears OK otherwise. Process: Rodinal 1:15 with 6ml hypo, bleach ½ std,
    redev rodinal 1:25, hardens good, no pre-bath.
    VerPan - Thin and grainy, grain related to thiness. Process: Rodinal
    1:15 10' with hypo 5ml, bleach ½std 5', clear by inspectio 1', redev rodinal
    8'.
    VP250 - reticulated, could it be the fix? Process: Rodinal 1:15 with
    hypo 7ml 9½', bleach ½std, full secondary exposure 4', redev Microphen full
    strength - slow but OK, finished off Bromophen1:1, 2'. Acid fix, hardener:
    colour film conditioner (formalin bath).
    Agfapan 100 exp200 - Very dark and contrasty, soft gelatin at start but
    OK on drying (could try fix without hardener). After treatment with weak
    ferricyanide to give good transparency. Good gradation at 100ASA. Try again
    with extra hypo or re-use first developer. Process: Rodinal 1:15 with hypo
    4ml, bleach ½std, full secdry exp. redev Bromophen 4½', very acid fix, film
    conditioner.
    Agafapan 400/400 - Bit thick, highlights not cleared. Used .... ? but
    bleach selective. Good surface, soft gradation but OK. Process: Rodinal 1:15
    with hypo 5ml, 10'. Bleach: Pot dichromate 45ml/10%soln, sulph acid (conc)
    6ml, water to 500ml. Clearing sod metabisulphite by inspection.
    Chemistry:
    Hypo: Sodium thiosulphate 25% soln (not fixer, but just the plain
    tradtional hypo crystals in solution).
    Bleach (standard):
    Pot permanganate 1g
    Sulphuric acid conc 5ml
    Water to 500ml
    (For ½std increase water or reduce chemical quantities to half.)
    Or, as I mixed it, for ease of use:
    16ml of 25% pot permanganate soln
    5ml of conc sulphuric acid (these days, try 50ml 25% sod bisulpate
    soln instead)
    Water to 500ml
    Hydrochloric acid can't be substituted for sulphuric in this bleaching
    process as the developed silver has to be removed. This is not the same as
    the bleach and re-develop for contrast control where the cloride or bromide
    is needed to so it can be re-developed. The silver here goes down the sink
    as silver sulphate leaving the positive image behind as unexposed film. Pot
    dichromate can be substituted for the permanganate and an alternative using
    this is:
    Stock solns:
    Pot dichromate 5%
    Sulphuric acid 5%
    To use pour 5ml of each into a 1litre of water. (Don't worry about 5%
    strength sulphuric, it doesn't taste nice, but doesn't cause any dramas).
    Bleach until silver disappears - about 5 mins.
    Another SAFE one (Weber):
    Pot dichromate 6g
    Sod bisulphate 20g
    Water to 1l
    Clearing bath:
    I didn't record any for the permanganate bleach so it probably wasn't
    needed.
    The dichromate does need it: 5% sod sulphite, 5 minutes (Kodak CB-1 has 9%
    soln). Some films are sensitive to clearing.
    Hardener: Formalin 2%
    Fogging: some peculiar chemical can be used but they may cause havoc
    elsewhere around the darkroom as well as being difficult to obtain and
    expensive. Bright light is needed for complete fogging and this is best done
    under water: 1min 30cm from a 100w light. May need several minutes if
    further away. Too much can be given.
    Some of the direct positives may have been capable of producing an excellent
    negative but not on lith processed as contone. If I had a proper contone
    film with a long scale and a suitable developer it probably would have been
    practical with a softer transparency developed out fully. The Agfa N31 would
    be a good choice. Kodak commercial 4127 and probably the new Aristatone
    from Freestyle may be suitable.
    Lith film is to be avoided if the direct process is to work. It is made for
    a purpose to form black or white, which is why the pinholes appear. The
    grains of silver in it have been designed to clump together by
    infectionously joining with adjacent ones during development and some
    interesting graphic affects can be had with different developers. Lith film
    has to be distinguished from contrasty continuous tone film which does not
    develop that way and where the tonal character can be changed. Ortho films
    typically are fairly contrasty.
    Kevin O'Brien
    Reversal processing is simpler and less fussy than all the formulations
    suggest. Most are very similar; the variations are probably result more from
    commercial copyright reasons than any other. One doesn't need to be a rocket
    scientist to do it, it's cheap and most of us have suitable chemistry
    already. A large part of the process can be carried out in dull room light.
    The aim for most here is to make what would be bad slides but what, when
    enlarged, would make thick, dense, long scale negs (just like we would have
    liked to have done in the camera). From experimentation, confirmed by the
    manufacturers, fast films - ASA 400 - can be reversed but are too soft for
    slides. Films like Pan F (50ASA) give brilliant slides but we have to
    reduce them so might as well take the bonus of a faster film to start.
    Another bonus- the reversal process gives finer grain from a given film
    because of the solvent added to the first developer. You may need to
    experiment with the film speed: minimum exposure leaves maximum density on
    the resulting transparency so you may gain a stop or more.
    Basic steps:
    (0. Optional formalin hardening bath.)
    1. Develop right out in developer containing a very weak silver halide
    solvent.
    2. Dip rinse
    3. Bleach out developed silver with acidic bath which also stops
    development.
    4. Clear bleach stains.
    4. Render remaining silver halides developable.
    5. Re-develop
    6. Quick rinse
    7. Quick fix/harden
    8. Wash
    1. First developer - The only control step.
    A choice of developers is possible The aim here is full development: Ilford
    PQ Universal 1+5, Bromophen, Rodinal (paraphenyldiamine), MQ, ID36, D158,
    D72, Eukobrom, Paterson Universal. Strength 3-4x regular film use.
    Add plain hypo 6-50ml of 25%soln i.e 2-12g/l of working developer. Faster
    films need the higher amounts. Ilford recommending 12g/l for FP4 plus or
    DELTA 100.
    The time in the developer is important as a vigorous development is needed
    and it is a race against the hypo which is trying to eat away the undevelope
    d silver. The longer the development the softer the result. Changing the
    quantity of hypo that would make a good slide also alters the gradation.
    2. Permanganate bleach
    Use your regular sulphuric or make:
    Pot Permanganate 2g (½l level tsp)
    Sod bisulphate 20g (rounded tbsp)
    Water to 1l
    It is possible to over bleach - but difficult. This bleach has only one job
    to do - eat away the developed silver so it can be washed out. Once the film
    has been in the bleach for 30s white light can be turned on and the rest of
    the process carried out.
    3. Clearing use 5% sodium sulphite or 3% sod metabisulphite (the smelly
    alternative with the sharp odour).
    4. This stage can act as rinse for the previous one. Keep the film wet
    remove it from any spiral and expose both sides for at least 1 min to a
    fluorescent light or 150w bulb at a distance of approx 30cm or 1ft. Don't
    splash the bulb! Avoid sunlight - you don't want to do printing out at this
    stage. Plenty of light to fully fog it - but not too actinic does the trick.
    Chemical foggers work but no one recommends them. They are also very
    hazardous to have around a working darkroom; a little bit of contamination
    could cause a lot of regretted spoilage.
    5. Re-develop in your regular paper or film developer (not lith or other
    alternative process developer). Dektol 1:2 works well.
    7. Rapid acid/fix hardener for regular recommended time. The time here is
    mostly for the hardening. Don't over do it as bleaching may occur.
    8. Final wash. Careful with drying, the film has had a hard day and you
    could give your new trannies a beautiful crinkle on their emulsion. Don't
    use the hair dryer. A little wetting agent or dish wash and hang to dry.
    Keep the temperature as even as possible throughout all steps to avoid
    reticulation and frilling, ideally within ±1ºF. If temperature control is a
    problem try hardening the film with a preliminary bath of 2% formalin. The
    rinses can be minimal, it seems to make little difference but it keeps the
    water useage down and reduces the risk of physical damage to the film.
    Stainless steel film holders and reels aren't recommended by some but it
    seems again to be inconsequential.
    Some experimentation is necessary to match your film/developer/hypo
    gradation requirements but that should be fairly easy.
    In a message dated 2/20/99, PM 05:22:54, alt-photo-process-l@skyway.usask.ca
    writes:
    <<Lith film is to be avoided if the direct process is to work. It is made for
    a purpose to form black or white, which is why the pinholes appear.>>
    Lith film can be successfully processed for low contrast, but to use it in
    direct reversal process is more difficult / challenging. The reason is if we
    process the film to low contrast, the high density area is not fully
    developed, so after the reversal, the Dmin would be high, which will give long
    printing time.
    The way to try to work around it is to expose the film to near the shoulder
    (but still have good separation) and then develop it to full in order to get
    reasonable Dmin, but of course when you do that, the contrast will be very
    high. I believe that is the reason why some are working on tests in the
    attempt to tame the contrast during the re-development.
    Dave S
    my real name, imagine that.

  3. #3

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    Mike,

    Thanks for your post. Do you suppose Kodak use a tin chloride solution as the reversal bath?

    Tom.

  4. #4
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    A note to Mike, some of the information is garbled or incorrect on-screen. You might want to edit it a bit.

    Tom; Kodak uses Stannous Chloride in the E6 reversal bath along with some stabilzing ingredients. They used t-Butyl Amine Borane in the E4 reversal bath. Both fog film quickly and TBAB is very toxic. Both are rather poor for keeping.

    PE



 

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