Page 1 of 4 123 ... LastLast
Results 1 to 10 of 33

Thread: If you’re a tray developer, this might raise your temperature

  1. #1
    Land-Scapegrace Heroique's Avatar
    Join Date
    Nov 2008
    Location
    Seattle, Wash.
    Posts
    2,929

    If you’re a tray developer, this might raise your temperature

    The chart below might surprise you if you’re tray developer.

    From a related thread, Steve Gledhill’s chart shows a significant increase in temperature of the developer solution (800 ml) during tray development – more specifically, a 2.5° C jump after 7 minutes, and a 4º C jump after 15 minutes. These changes are typically due, I suspect, to a combination of using the hands; the air temperature (if warm enough); and the heat-producing chemical reaction itself.

    Put more simply – it shows the developer solution’s average temperature is significantly higher at the end of the development step, than it was at the beginning.

    So that leads me to a few questions…

    1) Do you account for such changes when you “choose” a development temperature? Or, do you simply repeat the process that gives satisfactory results, and worry less than others about possible temperature changes?

    2) If you use a technique to keep temperatures constant (such as rubber gloves, slosher trays, water baths, etc.), have you actually tested the effectiveness?

    3) And, if your darkroom’s air temperature is different from session to session (say, winter vs. summer), might this influence the “slope” of the developer’s temperature line (for example, steepen it), causing inconsistent results & splitting headaches?

    -----
    What’s your personal experience? Can you share tips or insights about this?

  2. #2
    Scott Walker's Avatar
    Join Date
    Jan 2010
    Location
    Okotoks (rural), Alberta, Canada
    Posts
    956

    Re: If you’re a tray developer, this might raise your temperature

    I use a water bath, my sink has a fairly large basin and is ribbed so that there is 1 inch of water in the sink before it can even touch the trays and the bottom of the trays are also ribbed giving a bit more surface area. I normaly have about 2 inches of water in the sink and have tested the developer temp after developing once the film is in the fix and found no variation

    Pic of my sink

  3. #3

    Join Date
    Jul 2007
    Location
    Austin TX
    Posts
    2,049

    Re: If you’re a tray developer, this might raise your temperature

    Any tray development I do is at the darkroom air temperature and with forceps to handle the film, unless the tray is water jacketed. But by choosing special developer techniques for B&W it is possible to reduce or even eliminate the effect of temperature variations. Color processing is another matter altogether where it is essential to keep the temperature within +/- 1 degree or better.

    In the south, at high ambient temperature, the temperature rise can be even more dramatic than on the graph shown. For color work when the bath water comes in at 85 degrees F, or higher, I use a peltier 600 watt cooler run by a 15 amp DC supply to cool the bath water for a rotating drum.

    Nate Potter, Austin TX.

  4. #4

    Join Date
    Mar 2002
    Location
    now in Tucson, AZ
    Posts
    3,617

    Re: If you’re a tray developer, this might raise your temperature

    Anecdotal experience here. I process 4x5 b/w using 2 liters of developer in an 8x10 tray, agitating 6-12 sheets by shuffling them. Not long ago, while setting up a processing run, I decided to see how much the presence of my (gloved) hands in the tray affected the temperature. So as soon as the film went into the fixer, I went white-light and put the thermometer back in the tray. After 10 minutes of developing, the developer in the tray had gone from 68F to 68.5F. The room temperature was probably around 66F. So... for me, the variation is not enough to worry about. Of course, when I tested for my process time, the same conditions were in effect; so the minor dev-temp variation was accounted for right there.

  5. #5
    Abuser of God's Sunlight
    Join Date
    Aug 2004
    Location
    brooklyn, nyc
    Posts
    5,796

    Re: If you’re a tray developer, this might raise your temperature

    For film I anal-retentively control temperatures with water baths. All the way through from presoak to wash.

    With paper I let the chemicals do what they will, but I watch the temperature and adjust the time in each developer accordingly. Different developer agents respond differently (metol is more temperature sensitive than hydroquinone, for example), so I graphed the responses of the developers I use and consult them for final times. The difference is often unnoticeable in the freshly developed print, but makes a big difference in how the print tones in the toners I use.

    The only caveat is that I can't develop when things get really cold ... metol becomes more or less inactive below 65°. And that's warm for my place in the winter.

  6. #6

    Join Date
    Mar 2004
    Posts
    650

    Re: If you’re a tray developer, this might raise your temperature

    In my case, the opposite occurs, although I haven't taken the data for a graph. The humidity is normally low enough that that any solution in an open tray will drop several degrees in fifteen minutes. (I agitate by tilting the tray, so my hands aren't in the solution that much.)

    At 35% relative humidity and 25 C in the room, the equilibrium water temperature would be something like 15 C, although the air circulation rate isn't high enough to get it that far down.

  7. #7
    Abuser of God's Sunlight
    Join Date
    Aug 2004
    Location
    brooklyn, nyc
    Posts
    5,796

    Re: If you’re a tray developer, this might raise your temperature

    Quote Originally Posted by Harold_4074 View Post
    In my case, the opposite occurs, although I haven't taken the data for a graph. The humidity is normally low enough that that any solution in an open tray will drop several degrees in fifteen minutes.
    That's been my experience, too. Solutions get cooler than the air in the room. I've never figured out what caused it. I've lived in pretty humid places so it doesn't seem like that would be the only factor.

  8. #8
    Land-Scapegrace Heroique's Avatar
    Join Date
    Nov 2008
    Location
    Seattle, Wash.
    Posts
    2,929

    Re: If you’re a tray developer, this might raise your temperature

    Quote Originally Posted by Harold_4074 View Post
    ...The humidity is normally low enough that that any solution in an open tray will drop several degrees in fifteen minutes...
    Quote Originally Posted by paulr View Post
    That's been my experience, too...
    Harold’s remark about low humidity is quite interesting. Could low-enough humidity be causing a quick enough evaporation of the solution to reduce its temperature? Maybe the low humidity sloughs off the hottest molecules from the solution’s surface – like blowing on your porridge...

  9. #9
    Drew Wiley
    Join Date
    Sep 2008
    Location
    SF Bay area, CA
    Posts
    18,337

    Re: If you’re a tray developer, this might raise your temperature

    I use thin dimple-bottomed stainless steel trays for film development. Around this is a
    substantial water jacket. For critical work this is hooked to a thermoregulator which
    keeps the bath within 1/10 degree F! For more ordinary work or simple black and white
    print development, I just use the Zone VI compensating development timer. My sink room has R23 insulation around it, so stays very stable in terms of room temperature.
    This only changes significantly when the air exchanger is turned on. On especially cold
    days I will use a small Intertherm style heater to bring up the ambient air temp in advance of my work session. Usually I try not to keep my fingers in the developer for
    longer than necessary. I don't know exactly how to factor this in, but the water bath
    seems to do its thing, and densitometer measurements with step tablet tests etc show
    that my temp controls are extremely effective when a high level of precision is called for. For just ordinary Zone system work and general photography I simply use the
    drift by system with the water Jacket and Zone VI timer, and this is plenty good. The
    key is to have sensible ambient room temperature and a lot of water volume in the
    jacket or surrounding larger tray.

  10. #10
    windpointphoto's Avatar
    Join Date
    Aug 2004
    Location
    Racine, WI
    Posts
    262

    Re: If you’re a tray developer, this might raise your temperature

    Or use Fred Pickers Zone VI film developer timer which adjusts for temp change. This has been out since the 1980s and works well. Problem solved and you don't have to worry or think about this issue anymore. Usually available on ebay.

Similar Threads

  1. pyro developer, but which?
    By sergiob in forum Darkroom: Film, Processing & Printing
    Replies: 211
    Last Post: 27-Oct-2014, 22:30
  2. Better result with tray or tank developing?
    By jvuokko in forum Darkroom: Film, Processing & Printing
    Replies: 30
    Last Post: 29-Apr-2010, 02:58
  3. Old Formulas : Film
    By Paul Fitzgerald in forum Darkroom: Film, Processing & Printing
    Replies: 6
    Last Post: 19-Mar-2005, 21:31
  4. developer temperature
    By Chris Gittins in forum Darkroom: Film, Processing & Printing
    Replies: 12
    Last Post: 1-Feb-2004, 04:11
  5. Color Temperature and Continuous Spectra
    By John H. Henderson in forum Style & Technique
    Replies: 8
    Last Post: 13-Oct-2000, 11:08

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •