Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,561   Posts: 1,545,284   Online: 768
      
Page 1 of 4 1234 LastLast
Results 1 to 10 of 31
  1. #1
    osprey48's Avatar
    Join Date
    Apr 2007
    Location
    Keswick
    Shooter
    Multi Format
    Posts
    124
    Images
    106

    Accurate thermometer for C41

    What kind of thermometers do you use to process colour films? I've heard that the usual spirit ones I use for B&W are not accurate enough. Or are they?
    Does anyone use cheap kitchen food temperature probes? Or are they worse? Or doesn't it make any difference?
    Any info much appreciated.

  2. #2
    jscott's Avatar
    Join Date
    Aug 2010
    Location
    PNW
    Shooter
    Multi Format
    Posts
    84
    My choice for all darkroom applications is an instant read infrared beam model with digital readout. It's a gun-like gadget. Just aim it into your chemicals. Very accurate, fast, and easy.

  3. #3

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,842
    What type of thermometer you use is not important. What is important is that it be calibrated with another thermometer that you can trust. For this purpose I use two mercury filled lab grade thermometers with a range of -10 to 100 C.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  4. #4

    Join Date
    Aug 2010
    Location
    San Francisco
    Shooter
    Medium Format
    Posts
    483
    Quote Originally Posted by jscott View Post
    My choice for all darkroom applications is an instant read infrared beam model with digital readout. It's a gun-like gadget. Just aim it into your chemicals. Very accurate, fast, and easy.
    According to one maker's website: a backlit LCD shows temperature readings, and the thermometer has a range of -58° F-1,022° F--twice the breadth of typical infrared thermometers--and an accuracy within ±3.6° F.

    In other words, completely useless for home development...

  5. #5

    Join Date
    Apr 2008
    Location
    Oxfordshire, UK.
    Shooter
    35mm
    Posts
    2,214
    I use a Jobo 3321 which I was lucky to find on ebay cheap. Its scale is down to 0.2C and I think it's possible to read down to 0.1C
    Steve.

  6. #6

    Join Date
    Mar 2005
    Location
    Tasmania, Australia
    Shooter
    Multi Format
    Posts
    157
    I have a Kaiser precision thermometer. It has an expanded scale which makes it fairly easy to read to around 0.1C. Whether or not it's accurate is another question but providing it's consistent and my process is tuned for it, it's not a problem.

  7. #7

    Join Date
    Dec 2008
    Location
    Georgia, USA
    Shooter
    35mm
    Posts
    211
    I use cheap kitchen thermometers. I check them before use against a medical thermometer and apply any correction. Never had any problems……

  8. #8

    Join Date
    Apr 2008
    Location
    Oxfordshire, UK.
    Shooter
    35mm
    Posts
    2,214
    A question for those of you using household thermometers for C41: how do you hold the developer to +/- 0.15C? Household thermometers I've seen are usually +/- 1C. Have those of you with less accurate thermometers found these tolerances are unnecessarily tight?
    Steve.

  9. #9

    Join Date
    Jul 2011
    Shooter
    8x10 Format
    Posts
    2,601
    Kodak process thermometer. They've always been expensive but sometimes turn up used at reasonable prices. Don't confuse this with cheaper Kodak thermometers. Equivalent units can be obtained from scientific supply houses. Expect to pay at least a couple hundred bucks new.

  10. #10

    Join Date
    Jul 2011
    Shooter
    8x10 Format
    Posts
    2,601
    Maintaining correct temp can be done in a large water jacket in reasonable temp for "drift-by" technique. But a lab grade recirculating thermoregulator is the best way. For years I used a CPI
    Accutemp, which would easily keep water temps within a tenth F. When it finally burnt out I found
    something that cost almost a grand and is less convenient, so only use it only for really fussy work like color separation negatives. Thermostatic mixing valves aren't particularly good for critical use.

Page 1 of 4 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin