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  1. #21
    ROL
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    Quote Originally Posted by Christopher Colley View Post
    do you have any reason to believe that using the ilford temperature conversion chart produces inconsistent results?
    None. My comment is about generally accepted method of good practice, not Ilford extrapolations. If you want to standardize all of your developing procedures at 24C – and in some specific circumstances that may be necessary – be my guest. Just be aware that the heightened activity of developers, and resulting decreased development times at extreme temperatures may lead to variable results (i.e., inconsistent).

    Incidentally PMK Pyro developer procedures, which I've used exclusively for sheet film many years now, were standardized at 21C (70F). Hutchings told me that developing times for PMK should ideally be at least 10 minutes for full development, expansion or contraction. This normally necessitates working at close to 20C.

  2. #22
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    I'm happy with my Leonard valve, it holds the temperature where I want once I set it. But it does not do well at low flow. I run it through an entire darkroom session, and a good deal of water goes down the drain. I imagine the instantly-right-temperature-at-any-flow Intellifaucet is a good long-term value. Both in terms of time savings because you can turn it on just when you start. And water conservation because you can run it at low flow.

  3. #23
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    I use a warm-water bath to bring temperatures up. I pour the developer I need into a container, then put that container into a larger one with hot water. After a few minutes the developer temperature rises.

    To bring temperatures down, I use the same technique but with ice cubes, or I put the developer into the freezer for a few minutes. Less than 5 minutes in the freezer and my HC-110 went from 24c to 19c.

    Both techniques work well, and keep the temps high/low enough for the few minutes needed for the developing cycle.
    Those who know, shoot film

  4. #24

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    Small chemical quantities can best be 'tempered' to any photographic temperature with a water bath, provided you have enough space. To heat the water bath, look through chemical companies' catalogs to find an immersion heater. There is a unit marketed by Cole-Parmer that is accurate to about a degree F. The price was about $175 a few years ago, but the time and exasperation saved makes it worth it. I tried aquarium heaters, but the high capacity units did not provide accurate temperature control. My darkroom then becomes too hot in the summer and I've discovered that there are tropical-fish enthusiasts that display COLD-water species and need aquarium COOLERS. Again, read the specs carefully. AquaEuroUSA makes one for about $210 including a required circulation pump. The cooler always saves me a lot of exasperation. It has an LCD display, a real compressor (not a thermoelectric device) with water inlet and outlet, is a little smaller than a microwave oven, and accurately controls temperature to about one degree F. None of the civilian devices match (what I see as) the mythical +/- quarter degree color processing tolerance specified by some film manufacturers. There are also laboratory-grade immersion heaters/coolers in the thousand-dollar-plus range.
    [FONT="Arial"][/FONT]John Weinland

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