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  1. #21

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    Good Afternoon, Sperera,

    Generally, I use the T-Max Developer only for T-Max films. I don't recall the Kodak recommended times for 1:4, but my "normal" 1:7 times are 10 minutes for T-100 and 9 minutes for T-400, both at 68 degrees. When I need a little less or a little more contrast, I'll make "seat of the pants" adjustments (I don't have a densitometer). As is often stressed in these discussions, some experimentation is ordinarily a good idea to zero in on what's "normal" for your conditions.

    Konical

  2. #22
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    sperera:

    This has been covered in various ways in the posts above, but just in case it needs further clarification...

    You need to differentiate between the original concentrate (or powder), the stock solution (if any) and the working solution.

    The instructions for commercially prepared developers take one of three forms:

    1) for some developers, the instructions recommend that you take the developer in the form that it comes from the store (either powder or liquid) and make a stock solution from it. Then, when you want to actually use the developer, you take that stock solution and dilute it to make a working solution. D-76 is one example of this type of developer (although you can use the stock undiluted). If you follow the instructions on the bottle of HC-110, it too is said to work this way, although many here prefer instead to take small amounts of the concentrate (~6-10 ml) and dilute it directly to working dilution just before use;

    2) for some developers (almost invariably liquid developers), the instructions recommend that you take the developer in the form that it comes from the store and, when you want to actually use the developer, you take it and dilute it to make a working solution. T-Max developer works this way;

    3) for some developers, the instructions require that you prepare two baths, and each different bath is used (and re-used) at full strength. Diafine works this way.

    FWIW, I use HC110 and I do frequently make up a stock solution, but not with the entire bottle of concentrate. I only do this because I have more confidence in my ability to measure 120ml (as compared to 6ml) accurately.

    Matt

  3. #23

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    Quote Originally Posted by sperera View Post
    I normally cant go below 21 degrees so dev. times for that appreciated....
    You can probably bring the temperature to below 21C if necessary. To do so, use a water bath -- use a container with water in it at about the target temperature (a bit lower if you're trying to get to something under room temperature or higher if you need to get to something above room temperature). You then place your chemicals, and perhaps your loaded film tank, in the water. This brings the temperature of the developer to the desired temperature. For reducing temperature, you'd use a water bath that consists of a mixture of chilled water (from a refrigerator) and tap water.

    That said, 21C is not far from the usual 20C temperature -- and some times are given at slightly higher temperatures, too (about 24C, IIRC). There are tables and charts to help you adjust time for any given temperature; however, the details vary with each film/developer combination, so a "generic" table or chart can mislead as easily as it can help.

    also, whats this about the marbles!!!???
    Some people add marbles to developer containers to displace air as the developer is used. Developers go bad, in part, because they react with oxygen in the air, so minimizing the amount of air in a developer bottle will extend its life. Some concentrates, such as Rodinal and HC-110, are said to last a very long time without such measures, but others have much shorter life spans. Not everybody uses this trick, though; some use other tricks (such as using multiple small bottles rather than one big one, injecting an inert gas into the bottle, or using a vacuum pump to remove oxygen from the bottle), and some people just don't bother.

  4. #24

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    Hi,
    Mix your developers from scratch. I've found this the cheapest and easiest way to make small quantities.
    It's easy and it's fun !

  5. #25
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    Quote Originally Posted by Stew View Post
    Hi,
    Mix your developers from scratch. I've found this the cheapest and easiest way to make small quantities.
    It's easy and it's fun !
    It's cheap and easy if you have all the equipment needed already, but have you priced scales and the such lately, yikes. I can buy enough HC110 to do me for the rest of my life, for the price of even a cheaper lab scale ($200 or so), that will be accurate enough for the tiny amounts needed, especially in this country. There is also the issue of not everybody wants to waste half their photography time playing chemist.
    Paul Schmidt
    See my Blog at http://clickandspin.blogspot.com

    The greatest advance in photography in the last 100 years is not digital, it's odourless stop bath....

  6. #26

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    Quote Originally Posted by wogster View Post
    It's cheap and easy if you have all the equipment needed already, but have you priced scales and the such lately, yikes. I can buy enough HC110 to do me for the rest of my life, for the price of even a cheaper lab scale ($200 or so), that will be accurate enough for the tiny amounts needed, especially in this country. There is also the issue of not everybody wants to waste half their photography time playing chemist.
    I use the teaspoon method. A set of cheap teaspoons can be found for $1.00 at the dollar store. I know some purists scoff at the idea of using teasppons, but they have never let me down.

    I the back of The Darkroom Cookbook there is a conversion chart from grams to teaspoons.

    It takes only a bit longer to measure out the chems for D-23 than it does to measure out the proper amount of HC-110, but as always, whatever works for you.

  7. #27

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    Earth to wogster:

    For less than $20 you can get a digital scale and a 50 gram calibration weight. Amazon is your friend.

    http://www.amazon.com/Scales-Measuri...F8&node=289787

  8. #28
    wogster's Avatar
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    Quote Originally Posted by Venchka View Post
    Earth to wogster:

    For less than $20 you can get a digital scale and a 50 gram calibration weight. Amazon is your friend.

    http://www.amazon.com/Scales-Measuri...F8&node=289787
    Problem is, by the time I buy the scale, pay for shipping, brokerage fees, customs, taxes and convert that into real money (real money being the stuff that comes in my pay packet each week, and not what some company in the US is dealing with), I am looking at $150. Then if it ever breaks or needs recalibrating I need to pack it up, send it back to the US, do a bunch of customs paperwork, and hope the US repair facility has a person in their shipping department with a half a brain, that will do the
    proper customs declaration that gets it back to me, without my having to waste hours and hours on the phone fighting with customs. Been there, done that, will not make the same mistake again.
    Paul Schmidt
    See my Blog at http://clickandspin.blogspot.com

    The greatest advance in photography in the last 100 years is not digital, it's odourless stop bath....

  9. #29
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    If in Canada you have those who use firearms and who make bullets and load powder into cartridges, you will be able to find balances that are quite sensitive and accurate at much lower prices than for lab balances. There are no flaming digits to go bad and the only adjustment is in the form of a thumbscrew that adjusts for small changes in tare. They can be had for measuring gams or grains.

    I think I was the one who first promoted spoon measurements when I wrote the article "Kitchen Tested Soups" for Petersens Photographic in 1973. I not only presented a number of recipes, but I showed tests of uniformity and other facts. If you email me at pgainer@rtol.net, I will send you back a copy.
    Gadget Gainer

  10. #30
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    Gams? Don't I wish!
    Gadget Gainer

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