Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,556   Posts: 1,545,026   Online: 874
      
Page 2 of 2 FirstFirst 12
Results 11 to 15 of 15
  1. #11

    Join Date
    Jan 2007
    Location
    third stone from the sun
    Shooter
    Large Format
    Posts
    723
    Quote Originally Posted by jp80874 View Post
    If I understand you correctly the RH Design StopClock Vario takes care of this problem with a probe that measures output of the first exposure and duplicates it for the next unless of course you set it for a fraction of an f stop longer or shorter exposure. This new exposure is relative to the old measurement rather than starting over.

    http://www.rhdesigns.co.uk/darkroom/...ock_vario.html

    John Powers
    The timer you mention above plus others like it (the metrolux or the zone vi) are designed to compensate for variations in the intensity of light output. AFAIK, they are not designed to read the color temp. of the source nor can they compensate for problems of edge to edge eveness.

  2. #12
    ic-racer's Avatar
    Join Date
    Feb 2007
    Location
    Midwest USA
    Shooter
    Multi Format
    Posts
    6,220
    Quote Originally Posted by Mahler_one View Post
    As an aside, late last evening I had the opportunity to look about the Durst site to see if there were any comments concerning the Aristo cold light source and Durst enlargers. Mr. Jensen stated that the Aristo source was not good ( my words, not his ) in that the paint that was on the tubes had a tendency to peel and change, and thus the colors from the lamp grew unreliable. Hence, the waranty offered with the Aristo cold light head was exceptionally limited. I don't think I should post a direct quote from his site without his permission. However, I wonder if any of you have noted "color degradation" in the Aristo cold light tubes.

    Edwin
    My Aristo W-45 tube from 1988 has no flaking and provides a full contrast range with filtration.

    I documented the output of the lamp over five minutes. The intensity fell one-half stop.
    http://www.apug.org/forums/forum43/5...mperature.html
    Last edited by ic-racer; 08-31-2008 at 09:16 AM. Click to view previous post history.

  3. #13

    Join Date
    Oct 2002
    Posts
    1,159
    Quote Originally Posted by ic-racer View Post
    My Aristo W-45 tube from 1988 has no flaking and provides a full contrast range with filtration.

    I documented the output of the lamp over five minutes. The intensity fell one-half stop.
    http://www.apug.org/forums/forum43/5...mperature.html
    Thanks for going to the trouble of doing the experiment. Very thoughtful of you, and much appreciated.

  4. #14
    ic-racer's Avatar
    Join Date
    Feb 2007
    Location
    Midwest USA
    Shooter
    Multi Format
    Posts
    6,220
    Quote Originally Posted by Mahler_one View Post
    Thanks for going to the trouble of doing the experiment. Very thoughtful of you, and much appreciated.
    Basically I needed to answer the question for myself if I need a compensating timer or light stabilization system. Now that I know how the lamp behaves I can work around it with my current setup.

  5. #15

    Join Date
    Nov 2008
    Shooter
    Medium Format
    Posts
    1
    Hello ! I am Valentin, an amateur photographer from Romania. I just bought a DURST 138 enlarger and I want to buy a D57 cold light head from ARISTO. They say this unit has 1 lamp. Does anyone use this kind of cold light head ? Is this a good one ? I saw that some specialsts consider that the dye from the lamp dry and evaporates,, producing un-eveness. Is that true ? Shoud I buy also an compensating timer ?

    Best regards,
    Valentin

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