Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,699   Posts: 1,549,146   Online: 1122
      
Page 2 of 2 FirstFirst 12
Results 11 to 20 of 20
  1. #11

    Join Date
    Nov 2011
    Shooter
    35mm
    Posts
    15
    Thanks again for all the help. I'd post links to my results, but I am unable to until I make 5 posts.

  2. #12

    Join Date
    Mar 2011
    Location
    Vancouver, Canada
    Shooter
    Multi Format
    Posts
    141
    C-41 developing is easy peasy, not any harder than b&w really. I just use a beer jug of boiling water to bring my chemicals (the developer is the only one that really matters anyways) up to temperature and then it's no different than b&w developing from there.

  3. #13

    Join Date
    Nov 2011
    Shooter
    35mm
    Posts
    15
    Filler post.

  4. #14

  5. #15

    Join Date
    Feb 2008
    Location
    Winnipeg, Canada
    Shooter
    Multi Format
    Posts
    1,301
    Well the third pic looks ok, but you got some weird cross-over going in the first two, a red rubber tire and that red crud around the window. Whats up with that.
    Bob

  6. #16

    Join Date
    Mar 2011
    Shooter
    Medium Format
    Posts
    48
    The first thing that popped into my head when I saw these is "Where the hell are my damned chemicals!!" and a mental fist-shake in the direction of Macodirect. I desperately want to do my first roll of C41 but, well, 3 weeks and no chemicals...

    Your success is not helping my lack of patience.

    How did you end up approaching the temperature stability problem?

    Also as a general question, the thermometers I can find are all +-1C accuracy to match national food preparation standards. I'm sure they are better than that in reality, but I don't know how much. I was looking at a human thermometer (32-42C +-0.1C), but they have slow response times and small measurement surfaces. Can anyone suggest a good thermometer and where to buy?
    Last edited by postalman; 11-16-2011 at 11:30 PM. Click to view previous post history.

  7. #17
    Mike Wilde's Avatar
    Join Date
    Aug 2006
    Location
    Misissauaga Canada
    Shooter
    Multi Format
    Posts
    2,939
    Images
    29
    I have one 'reference thermometer' that rarely comes out of it's case. It is accurate, and yes, also slow. It is also over 2 feet long and goes from -10 to 150F in 1/5 of a degree F increments.
    Amazing stuff crawls into your life when you make a habit of scouring liquidation auctions aover a decade when manufacturing, and hence usually also R&D sections are shutting up locally and moving overseas.

    All other 'user' thermometers of the mercury(yes, still a few), alcohol, bimetalic dial type, and electronic, all get measured against the reference at 20C and 38 C every year or whenever they get a new battery, or have been dropped.

    The deviation from the reference standard is sharpied onto a sticker that gets pasted onto the non-reference thremometer in question.

    Then I know for instance, when the thermometer in the c-41/e-6 bath says 38.4 I am really at 38, since the sticker says subtract 0.4C.
    my real name, imagine that.

  8. #18

    Join Date
    Nov 2011
    Shooter
    35mm
    Posts
    15
    I used the electronic thermometer my family uses when we are sick

    1. I poured hot sink water (about 110F) into a big tupperware.

    2. I let the checmicals sit in the hot bath until they reached about 105F

    3. I cooled the bath to 105F

    4. Once the bath and chemicals started to drop in temp, I began the first step of development (soaking the film).

    5. I checked the temp in the tub every couple minutes and poured hot water in when it dropped below 102.

  9. #19

    Join Date
    Aug 2011
    Shooter
    Medium Format
    Posts
    38
    I use a Tetenal C-41 kit. I have trouble with it and as far as I understand there are 2 variables that may still vary... actual temperature and my water.

    Keeping the temperature constant is no trouble in the kitchen sink, 10 litres of 45 C water is allowed to cool with the chemicals in bottles. When at 38C [recommended 38-38.5C] I start the 3:15-phase. It takes more than 10 minutes for the temp to cool down to 37C.

    But I am unsure if the temp is 38 or, say 40C, etc. The precision is there but accuracy? Must get a better thermometer.

    My water might also have a bit too much calcium in it giving a lower pH than it should. Next time I'll get distilled water just too be on the safe side.

    Still it is fun and more rewarding than B/W and Rodinal or HC-110.
    Last edited by emjo; 11-18-2011 at 03:02 PM. Click to view previous post history.

  10. #20

    Join Date
    Mar 2011
    Shooter
    Medium Format
    Posts
    48
    Quote Originally Posted by emjo View Post
    But I am unsure if the temp is 38 or, say 40C, etc. The precision is there but accuracy? Must get a better thermometer.
    This is what I'm wondering about. It seems food grade thermometers are +-1.0C or thereabouts accuracy with +-0.1C resolution, whilst medical ones are +-0.1C accuracy and resolution. Unfortunately calibration with ice+water and boiling water @ 1atm only works for the less accurate thermometers that have the larger range (and you're also making some BIG assumptions about the linearity of the response of the cheap $0.01 thermistor they use).

    But I'd be willing to trust a $10 medical grade one unless someone tells me not to and just accept the slow response time, because as you say, if you get enough water (I plan to use an insulated tub it has a much slower response time than the thermometer will.

    totowroe - Please tell me you mean the same model of thermometer as you give to your family... That may be why they're not feeling well

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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