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  1. #21

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    Quote Originally Posted by Photo Engineer View Post
    As for the KMAX and TMAX in the MSDS, note that the Kodak formula contains a phenidone type developing agent whereas the KMAX does not. Also, the Kodak formula does not contain any potassium salts. In addition, the Kodak developer contains DEA, but the other one does not list the alkali at all.

    These are thoughts to consider when thinking about similarity.

    PE
    That's what I thought and was asking about. Thank you.

    I pretty much have come to the conclusion that, in regards to my film and developer choice, it's TMX, TMY-2, and TMAX - accept no substitutes!

    I'd like to know why, in this era of modern film bases that don't need hardeners, why Kodak still puts a hardener in their fixers.

  2. #22

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    Quote Originally Posted by JustDave View Post
    I had this thought, why don't I just look at the bio hazard sheet and compare chemicals? (I see where you get a manufacturer for a house brand Arista Liquid Film Developer = Clayton).
    Anyway, as an example, I compared KMAX with TMAX:
    TMAX:
    50 - 60 Water (7732-18-5)
    35 - 45 Diethanolamine-sulphur dioxide complex (63149-47-3)
    1 - 5 Sodium metabisulphite (7681-57-4)
    1 - 5 Hydroquinone (123-31-9)
    0.1 - 1 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone (13047-13-7)

    KMAX:
    POTASSIUM SULFITE 10117-38-1 N.E. N.E. 10-15
    HYDROQUINONE 123-31-9 2mg/m³ 2mg/m³ 1-5
    DIETHYLENE GLYCOL 111-46-6 10mg/m³ (WEEL) 50 ppm TWA 1-5

    Now, it's been decades since my college chemistry classes, but from what I remember (not much), aside from the Hydroquinone component, these developers aren't identical. BUT! I guess TMAX developer is just a Hydroquinone developer and when shopping for a developer, I should just look for a Hydroquinone developer? The Hydroquinone is what really counts?
    The safety data sheets only need to list dangerous ingredients, and for dangerous ingredients (classified as irritant, harmful or toxic) there are minimum concentrations below which they don't have to be listed, IIRC 1% for harmful substances. This, along with the imprecise percentages, is designed to allow manufacturers to keep their trade secrets.

    Therefore, I would assume that the KMAX developer is of a PQ type as well, although phenidone or dimezone are not listed.

  3. #23
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    You buy Peace of Mind when you buy the name brand. The house brand can be a bit of a gamble. For me, the goal is the image, the price is the cost.

    I am so fed up with the look alike products imported and prove to be crap in disguise. Walfart is the master of this sham, sadly, not the only ones doing it.

    With some exception, you get what you pay for.

    JMHO
    Items for sale or trade at www.Camera35.com

  4. #24
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    Quote Originally Posted by JustDave View Post
    That's what I thought and was asking about. Thank you.

    I pretty much have come to the conclusion that, in regards to my film and developer choice, it's TMX, TMY-2, and TMAX - accept no substitutes!

    I'd like to know why, in this era of modern film bases that don't need hardeners, why Kodak still puts a hardener in their fixers.
    In Kodak fixer with hardener, the hardener is an option to be used at your discretion. Kodak knows that there are softer products out there that may need it.

    So, it is a convenience to you.

    PE

  5. #25

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    Just to oversimplify, and to confine attention to the Freestyle house brands: Is it safe to conclude that the films are neither more nor less than relabelled "brand" films, but the chemistry may be separately formulated "work-alike" stuff? I guess we can almost know from the discussion above that KMAX is not just relabelled TMAX developer, for instance.

    Or are you, PE, suggesting *also* that (as an example) Arista Premium 400 might not be exactly the same as TX400 after all?

    -NT
    Nathan Tenny
    San Diego, CA, USA

    The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
    -The Little Technical Library, _Developing, Printing, And Enlarging_

  6. #26
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    Nathan;

    It may not be. Who knows? It depends on the contract between the manufacturer and the recipient what the properties of a given product will be. If they elect certain features and leave others out, then that is what they get. There is a menu of options available in any contract between companies that establishes specifications.

    PE

  7. #27

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    Quote Originally Posted by JustDave View Post
    I guess TMAX developer is just a Hydroquinone developer and when shopping for a developer, I should just look for a Hydroquinone developer? The Hydroquinone is what really counts?
    Yes and no, but mostly no. First, there are several developing agents that are important/common. I tend to think of four as being associated, although only three are really in common use in commercial developers:

    • metol (aka elon; abbreviated M)
    • hydroquinone (abbreviated Q)
    • phenidone (or variants, such as Dimezone S; abbreviated P)
    • ascorbic acid (or variants, such as sodium ascorbate; abbreviated C)


    Most common developers today use two of these four agents. The MQ combination is extremely common, with PQ accounting for most of the rest. PC developers are rarer but they do exist (for instance, Kodak XTOL film developer, Silvergrain Tektol print developer). I don't know of any commercial MC developers, although there are mix-it-yourself MC developers. I don't know of any MP or QC developers, period; AFAIK, those combinations aren't superadditive (see below). A few developers use just one of these agents (I believe metol is the most common in this regard). A very few developers use three or more agents.

    Developing agents are combined for various reasons. One is superadditivity -- the two developers work more quickly together than they do separately, even adjusting for the quantities involved. Another is that each developing agent has its unique character, so by combining them, you can get better results than you can using them individually.

    Metol and phenidone have roughly similar characteristics, and can often be substituted in a formula (but you use about 1/10 as much phenidone as the formula calls for metol, or vice-versa). Likewise for hydroquinone and sodium ascorbate (I don't recall the substitution ratio, though; and ascorbic acid is more acidic and so requires additional formula changes to bring the pH into balance). Note the word "roughly" earlier in this paragraph; I do not mean to imply that P and M or Q and C work identically! Changing a developer in this way will change its character a bit, but it will probably work.

    Note that there are more than these four developing agents. Things like para-aminophenol (used in Rodinal) and catechol (used in many "pyro" developers) are also sometimes used, occasionally in combination with one or more of the others I've listed.

    Now to the main point: I don't know the long names you've listed by heart, but I believe Kodak's TMAX developer is a PQ developer. As such, it's the combination of those two agents that contributes to the developer's character, not the hydroquinone alone. Other ingredients also have an effect; for instance, sodium sulfite is often cited as an ingredient that reduces the apparent size of grain. (This is a topic about which much more could be -- and has been -- written.)

    Thus, the bottom line to my post is that finding an equivalent to Kodak's TMAX developer (or any other developer) is a lot more complex than just looking for one with hydroquinone in it. The hydroquinone interacts with any other developing agents, and with other components, in ways that are really rather complex. One further point: It's my understanding that phenidone is used in such small quantities that it's often omitted from ingredient lists. This can complicate analyses like this.

  8. #28

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    Quote Originally Posted by ntenny View Post
    Just to oversimplify, and to confine attention to the Freestyle house brands: Is it safe to conclude that the films are neither more nor less than relabelled "brand" films, but the chemistry may be separately formulated "work-alike" stuff? I guess we can almost know from the discussion above that KMAX is not just relabelled TMAX developer, for instance.

    Or are you, PE, suggesting *also* that (as an example) Arista Premium 400 might not be exactly the same as TX400 after all?
    As others have said, it's conceivable that house-brand films aren't identical to current name-brand offerings. Ilford is known to make B&W products to other companies' specifications, for instance. Anything more than very minor tweaks can usually be spotted by experienced photographers, both by examining the results and by scrutinizing suggested developing times. Neither test is really 100% conclusive, but if nobody can tell the difference between, say, Tri-X and Freestyle's Arista Premium 400, does it really matter if there's some small difference in the emulsion, the base, or whatever?

    For chemistry it's a bit more open, since the requirements to design and manufacture unique photochemistry are less difficult than the requirements to design and manufacture unique films and papers. I believe Freestyle's photochemistry supplier is known, but I've not paid a lot of attention to this, so I can't name a name. I don't believe it's Kodak or the company to whom Kodak sold their chemical manufacturing arm, though. Of course, developers have only a few ingredients, so another firm could supply an identical or near-identical product (legal issues aside; I don't know what patents, if any, apply to TMAX developer). Some developers, such as D-76, have published formulas that anybody can replicate -- although Kodak's D-76 is widely believed to have proprietary deviations from the published D-76 formulation.

    The point being that the issues involved in identifying work-alike or identical products in films and papers are very different from those for photochemistry. Freestyle's suppliers for the two classes also happen to be different.

  9. #29

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    Quote Originally Posted by srs5694 View Post

    ....

    Thus, the bottom line to my post is that finding an equivalent to Kodak's TMAX developer (or any other developer) is a lot more complex than just looking for one with hydroquinone in it. The hydroquinone interacts with any other developing agents, and with other components, in ways that are really rather complex. One further point: It's my understanding that phenidone is used in such small quantities that it's often omitted from ingredient lists. This can complicate analyses like this.
    Thanks for the detailed reply.
    I kind of got that impression also from PE.

    I guess I caught up in the hype from the FreeStyle catalog I received last year. Save money with cheaper brands of your favorite chemicals!
    And they showed: KMAX, Arista 76, etc...

  10. #30

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    You can save money with cheaper workalike products. You'll have to either take Freestyle's word that their Product A works like another company's Product X, though, or ask about them specifically here or somewhere else. Also, even if A isn't all that much like X, A may be a perfectly good product. There are dozens or hundreds of commercially-manufactured photographic developers available today. Each and every one of them sells enough to be manufactured, which means that somebody likes each and every one of them.

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