Please define/clarify at 'room temperature'

Discussion in 'Color: Film, Paper, and Chemistry' started by VaryaV, Oct 11, 2011.

  1. VaryaV

    VaryaV Member

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    There seems to be some confusion on my part and I will explain below.

    This is in regards to me using Efke50/Adox50 in Rodinal. I was given tips by several people that this film needs temperatures that are consistent and 'at room temperature' and souped in distilled water..... ok. (here lies the problem):

    I have always thought and do develop all of my films at 68 degrees F. This means that I add hot water or ice cubes to adjust the temp. I live in FL where it gets very hot. In summer when it's 100+ degrees I keep my d/r (which is outside) at 68. When it's cooler at 80 the studio runs 72-76. and in winter it can be anywhere from 55 to 65 degrees.

    Last night I souped my first batch at 72 as that was the current 'room temperature.'

    Now... do you really mean 68 is room temperature?.... Always?... because I assume the warmer or colder temperatures then would have to be considered into either extending or shorten dev. times and I don't want to go there. and I don't think I can soup film in 55 degree water at the same time across the board as I would 72. I don't want to be constantly adjusting for times.

    Now, if I do my normal route of adding ice or hot water to equal 68 with these films will that be good enough? if my dev/stop/fixer are all at that 68?

    Thank you .... just wanting clarity because it is obvious chemical reactions change with temperatures.

    Any feedback would be welcome.
     
  2. SuzanneR

    SuzanneR Moderator Staff Member Moderator

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    I consider room temp to be between 67 and 73 degrees, but I think it's more important to be consistent than accurate. If it's easier to keep your temps closer to 72 degrees F, then use that as your room temp, but always use it.
     
  3. Rick A

    Rick A Subscriber

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    I always develope at "room temp", and adjust my time accordingly. If my chems happen to be 68f then I use the time for that, if 70f then I check the time/temp chart and use the time given. For years I only used 68f as my temp, but I find room temp as more convenient.
     
  4. VaryaV

    VaryaV Member

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    When you do that, do you also reduce your development time by a 1/2 stop or full? or do you keep them the same as you would for 68 to make up the temperature difference?

    Sorry, this never was an issue until I starting testing different films.

    It's much easier to do at room temps 'if' I can keep the d/r steady. being as the building it outside it's much, much harder to control both the water and air. The water supply was put in after it was built so we were unable to run the lines underground.

    Sorry, Rick I just saw your post.
     
  5. X. Phot.

    X. Phot. Guest

    Last edited by a moderator: Oct 11, 2011
  6. brucemuir

    brucemuir Member

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    I haven't tested myself but read right here that Rodinal gives even courser grain at higher temps.
     
  7. Ian Grant

    Ian Grant Subscriber

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    When in the UK I process at 20°C regardless of the room temperature, mainly because the water temperature never rises above that, and that's more important.

    In Turkey I always process at the tap water temperature in the summer which is a very constant 26-27°C, however this is to high for EFKE films - 22°c would be the maximum I'd use for them.

    As Suzanne says it's the consistency that's more important and that means keeping the whole process cycle so that there's never more than +/- 1°C between stages including washing.

    Ian
     
  8. ROL

    ROL Member

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    Room Temperature = 68ºF = 20ºC.

    Development times decrease with increasing temperature, and vice versa, within experimental ranges given by film manufacturers, as in the previous post. Most films standardize at 20ºC, around 10 minutes total developing time.

    Consistency is key. However, I'm never overly concerned with a degree variation with developer for panchromatic films, particularly over the relatively short course of time indicated, even if ambient temperatures are at somewhat greater variance. Though this condition to, may be mitigated without AC by choosing a time and environment to work in each day that is close to "room temperature".
     
  9. Ian Grant

    Ian Grant Subscriber

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    That's not true at all, the developer temperature itself has no effect on the grain as long as the times's adjusted.

    However Rodinal contains Potassium Hydroxide which softens the emulsion and any variations in temperatures between stages - dev/stop/fixer/wash can cause micro reticulation (surface reticulation) which makses resulting prints/scans appear much coarser grained. This only happens with a few emulsions.

    Ian
     
  10. brucemuir

    brucemuir Member

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    Yea, I was curious as to what caused this if only for my own understanding.
    I asked in the thread where it was stated but maybe my post got lost in the clutter.

    Like I said I haven't ran into the issue as I almost always run 68/20c and slightly warmer in summer.
     
  11. VaryaV

    VaryaV Member

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    Thank you all for this very valuable information. It has really clarified some current issues I am dealing with.

    Sometimes, when you try new films and developers that are in complete opposition to your normal methodology it throws you for a loop. :D
     
  12. Jeff Kubach

    Jeff Kubach Member

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    You can move where I live and have more normal temps!:laugh:

    Jeff
     
  13. VaryaV

    VaryaV Member

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    Tell me about it. I have to run the a/c and de-humidifier constantly in the summer and heat in the winter... would I have to move to San Diego to get year around consistency?
     
  14. MattKing

    MattKing Subscriber

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  15. GumPhoto

    GumPhoto Member

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    We had discussed earlier room temperature as being important for Stand Development, so if your not doing Stand, then forget this. But if you are, then a few observations I've read while researching: Stand development depends upon having film stand in very dilute motionless developer for a long time. In theory, the developer will exhaust itself in the highlights and continue to work in on the shadows and midtones. If the developer is allowed to shift and move around, then the highlight areas will continue to get fresh developer, and will become blocked. If the developer is not the same temperature as the air outside the tank (room temperature), then it will necessarily adjust itself to BECOME room temperature, and this adjustment will cause currents and eddies in the tank and move the developer around. I can't cite the sources at this moment, but I've read that the temperature really isn't all that critical, but the stillness of the developer certainly is. I keep a few jugs of water in my darkroom all the time so that I always have "room temp" water available. In two months, when the Illinois winter begins to kick in, my darkroom will be 10-15 degrees (F) cooler than it is, and then I'll see just how "uncritical" the temperature really is.
     
  16. VaryaV

    VaryaV Member

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    So are your results for stand development the same regardless whether room temperature is 68 or 55? I know if you let it stand for 1 hour it may not be as critical as a 13, or 10 minute.... or will it still shift the curves?

    keep me posted.
     
  17. jeffreyg

    jeffreyg Subscriber

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    I start with developer at 68F and room temp at 72-74 and use developing time as per mfg. unless I want more contrast. Keeping consistent as was mentioned is probably the best suggestion. If you are getting the results you want, why rock the boat?

    If someone is so inclined they could mix the volume of developer you use, cool or warm it to 68F use the time recommended and measure the temp at even intervals. Take the average and use the time for that temp. Then take two rolls at the same exposure setting. Develop one for the average and one at the time for 68F. Compare the negatives and see if it is really worth changing your routine.

    http://www.jeffreyglasser.com/
     
  18. georg16nik

    georg16nik Member

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    For the classical Adox emulsions 20° C / 68F is the golden spot.
    Rodinal is very demanding, when it comes to those type of emulsion.
    Distilled water and also, filter Your fixer if not 1st timer.
     
  19. Copperrein

    Copperrein Member

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    I generally have a 20C room temp that works decent for all my chemistries
     
  20. TareqPhoto

    TareqPhoto Member

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    In my country, they stated 25C as the room temp, but in the summer the temp in room can reach 35C and in winter it can go down to 18-20C, so i adjust the temp of the chems to be at 20-22C all the time.
     
  21. terrywoodenpic

    terrywoodenpic Member

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    traditionally 68/20 was the normal processing temperature as it was easy to maintain.

    However the killer was sharp changes in temperature between baths and washes that could lead to reticulation and even frilling. ( emulsions are tougher today)

    the temperature you can easily maintain your wash water is usually the way to go, as you can use it as a water bath to maintain all other temperatures.

    The problem then is only if you can not maintain it with in about 8 degrees of 68. when other strategies are needed. like warming or cooling. (to avoid excessively long or short times)

    The available time temperature curves and tables are very accurate and can be relied upon.
     
  22. Leigh B

    Leigh B Member

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    Room temperature is an industry standard (68ºF/20ºC) introduced perhaps 100 years ago, based on the average temperature in darkrooms at the time.

    It's the basis for "standard" development times, which are generally temperature sensitive.

    It has nothing to do with the actual temperature in your (or anyone's) darkroom at the time of processing. It's just a standard.

    - Leigh