Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,769   Posts: 1,484,215   Online: 929
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1

    Join Date
    Sep 2002
    Location
    127.0.0.1
    Shooter
    Multi Format
    Posts
    604

    DTOD in Kodak D94A for motion picture film

    Does anyone know what chemical DTOD is? Kodak says it is C6H14O2S2, but I'd like to know what the common name is so I can order some.

    Kodak replaced the old B&W motion picture film D94 developer and R9 potassium dichromate bleach formulas with D94A and R10. The main impetus for this change was to eliminate the heavy metal chromium used in the old bleach. The new R10 bleach is a permanganate bleach.

    I always have mixed the D94 developer and R9 bleach from bulk chemicals. I'd like to do the same with the new D94A and R10 bleach, but the new first developer has this DTOD.

    Here is the old D94 formula:

    Kodak D-94

    Water, 50 degrees C (125 F) 750 ml
    Kodak ELON (Metol) 0.6 g
    Sodium Sulfite (anhydrous) 50.0 g
    Hyrdoquinone 20.0 g
    Potassium Bromide (anhydrous) 8.0 g
    (or 7.0 g Sodium Bromide)
    Sodium Thiocyanate (liquid) 9.1 ml
    Sodium Hydroxide 20.0 g
    Water to make 1.0 L

    And the new D94A devloper

    Kodak D-94A

    Water, 50 degrees C (125F) 750ml
    Kodak ELON (Metol) 0.6g
    Sodium Sulfite (anhydrous) 60.0 g
    Hyrdoquinone 20.0 g
    Sodium Bromide 7.0g
    DTOD 0.42g
    Sodium Hydroxide 20.0 g
    Water to make 1.0 L

    The formulas are pretty similar. There's no Sodium Thiocyanate in the new D-94A, but there is this new DTOD. Sodium Bromide replaces Potassium Bromide, and the amount of Sodium Sulfite is increased.

    The amount of DTOD is less than half a gram per liter of developer. Can anyone suggest what might happen if I just left it out?

  2. #2
    Helen B's Avatar
    Join Date
    Jul 2004
    Location
    Hell's Kitchen, New York, USA
    Shooter
    Multi Format
    Posts
    1,557
    Images
    27
    DTOD? Dithiaoctane diol? It is a silver halide solvent, so it sounds like a replacement for the thiocyanate, but maybe (I'm not certain, and don't have my reference 'library' here) with better granularity controlling properties because emulsion softening can be a problem when you switch from dichromate to permanganate bleach. I'd be inclined to ask EK - the Motion Picture dept people are always as helpful as they can be - or even Goldschmidt (I think that their name has been mis-spelled by EK in H24-15).

    Here it is from ScienceLab at $50 for 25 g.

    It is also used in ripening during emulsion manufacture - as is thiocyanate.

    I'm not sure if any of that is practically useful - unless you can find a lab able to sell small quantities and you don't mind handling it.

    Best,
    Helen

  3. #3

    Join Date
    Sep 2002
    Location
    127.0.0.1
    Shooter
    Multi Format
    Posts
    604
    Thanks, Helen. I appreciate the info, and especially the link to ScienceLab. It's definitely helpful.

    25 grams is enough for 59 liters of developer, but at a cost of $50 (plus hazardous shipping fee...) it certainly makes D94A a considerably more expensive developer than D94. Perhaps I can find a cheaper source, or maybe I'll just stick with D94 after all. I don't think I put enough heavy metals into the environment with the tiny amounds of R9 bleach I use to worry much about it. Or to keep me from rationalizing my use of it.

    A couple of the guys from filmshooting.com were wondering about DTOD, too, so I'll point them to this thread.

    Thanks again,
    Skip.

  4. #4

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,048
    How much of a hazardous material is "enough"? What happens when eveyone discharges a "tiny" amount? Your actions might not affect you, but they might affect someone else.

  5. #5

    Join Date
    Sep 2002
    Location
    127.0.0.1
    Shooter
    Multi Format
    Posts
    604
    Jim, hexavalent forms of chromium in the environment come primarily from industrial sources. Chromium is used the production of various types of steel, e.g., chrome steel and stainless steel. Stainless steel contains 11 to 18 percent chromium. Potassium Dichromate and Sulfuric Acid (same as Kodak R9 bleach, albeit perhaps different concentrations?) is used to clean laboratory glassware (non-chromium alternatives are beginning to replace the dichromate versions). An alloy of nickle and chromium is used to produce the heating elements in electric coffeepots and toasters and broilers and ovens and cup warmers and virtually anything else with an electric heating element. It's used in hardened metal cutting tools and in surgical tools. It's used in some leather tanning processes. It's used in the production of pressure treated wood and in concrete cement. It is used along with cobolt in blue and green colored pigments such as eye-liners and other makeup products. It is an airborne byproduct of burning coal. Chromium is used as a film intensifier (less toxic than selenium, by the way), and in tiny quantities as a contrast agent in platinum and palladium paper developers, and also in light sensitive emulsions for alternative photographic processes such as ceramic and enamel processes.

    If you research it a bit, you'll find websites that identify common products containing chromium, and list uses such as alloys of metallurgy, adhesives, anticorrosives in antifreeze, oils, and paints, automobiles, bleach, blue prints, bricks, catgut sutures, cement, ceramics, chrome plating, chrome steel, copy paper, dental implants, detergents, drywall, electroplating, electric batteries, engraving and lithography, eye shadow, fireworks, floor wax, foundaries (added to sand for bricks), glue, green dyes, ink, mascara, matches, milk testing, mortar, orthopedic products, pacemaker wires, paint (green, orange, yellow), photography (color developing, as well as b&w reversal processes, alternative processes), pigments, plaster, pool table felt, shoe polish, stainless steel, leather tanning, tattoos (green), textile dyes (military green), TV manufacturing, Vitamin supplements, welding, and wood preservatives. I'm sure there are more.

    Since you are on this forum Jim, I'm assuming that you are a photographer, and not a mudhut-groveling luddite who believes that humans should abandon modern technology and the comfort and prosperity it brings about in order to return to an agrarian or hunter-gatherer society. Do you work in a darkroom, or just farm the dirty work out to someone else? Do you recapture the silver from your fixer before discarding it? Do you collect your selenium toner and bring it to a hazardous waste facility? If you do, then of course, you have my respect for that.

    When I built my darkroom, I visited my city wastewater engineer and asked him about disposing of hazardous chemicals, heavy metals, silver recovery, and so forth. After getting over his incredulity that I took the time to contact him to discuss the matter, he told me that the city wasn't concerned about the metal-bearing effluent produced by home hobbyist darkroom enthusiasts, not even the silver, which is by far the greatest contaminant. He told me I could just dump it down the drain, that the amount that I could produce in a home darkroom wouldn't be detectable in the water treatment plant.

    But if you are a luddite, I suggest you give up photography, and modern living. You never know just how much damage your lifestyle may be doing to others.

  6. #6

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,048
    Sorry, but this long-winded excuse that "everyone else does it, so it must be ok for me" doesn't cut it; and I am careful of what I dispose of and how I do it.

  7. #7
    fhovie's Avatar
    Join Date
    Mar 2003
    Location
    Port Hueneme, California - USA
    Shooter
    Large Format
    Posts
    1,246
    Images
    92
    Hey Skip - can I quote you on that - That is the best tie raid I have read ... ever! Wow. I am still chuckling here. Thanks. and ... I agree with you. Man was created to dominate the earth. It was created for us - we are not an evil parasite here. And, of course, we do want to take care of it intelligently and to a great degree, we are.

  8. #8

    Join Date
    Sep 2002
    Location
    127.0.0.1
    Shooter
    Multi Format
    Posts
    604
    Thanks, fhovie, and feel free to quote me. While I don't subscribe to a belief in creation, I certainly agree that we are as much a part of the world as every other part of nature, and it is in our best interest to care for the earth, our home, and use it intelligently. I do see signs that we are doing better at it. At the same time, there is simply no such thing as zero impact living.

  9. #9

    Join Date
    Sep 2002
    Location
    127.0.0.1
    Shooter
    Multi Format
    Posts
    604
    Jim, as photographers, we all have to come to grips with the reality that film and photographic paper production and processing involves the use of a number of organic and inorganic chemicals and compounds, some of which are toxic and environmentally unfriendly, either directly or indirectly. Just think of all the cows whose hooves go into making gelatin for film and paper emulsions, and the impact that raising those cows has on the environment.

    Even if you bottle the more ojbectionable effluents you produce and bring them to a hazardous chemical disposal facility, some traces of it will get out into the environment. Not all of it will be rendered 100% harmless.

    So you've reduced the tiny amount of heavy metal pollution to an even tinier amount. Good. I do the same with silver, at least. But still, your actions as a photographer might affect someone else. It's just a matter of degree, right? In that case, you might seriously want to give some thought to moving into a mud hut in a clearing in the woods, eschew all modern conveniences and technology and medicine, and yes, your computer, and use of electricity, excessive consumption of forest products, and be careful about the types and quantities of foods you eat (since human waste itself can be harmful in sufficient quantity). Also, be kind enough to limit your reproduction to just the number of children sufficient to replace yourself and your mates, so as to not put more pressure on the earth. And before you finally take leave of the world, kindly insist that your family dispose of you in a green burial site, so at least the earth can get a little bit back of what you took from it.

  10. #10

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,048
    Skip, I'm curious. You've asked me if I dispose of certain chemicals in a proper way by taking them to a hazardous waste area, but yet you're going to dump a chemical with chromium down the drain???

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin