Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,691   Posts: 1,548,945   Online: 797
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 24
  1. #11
    Lukas_87's Avatar
    Join Date
    Jan 2008
    Location
    Prague, Czech Republic (Europe)
    Shooter
    35mm
    Posts
    114
    Images
    2
    sorry for double post, I thought it was not posted correctly...

    actually - a lot of the modern emulsions (Delta 100, 400, 3200, Neopan 400, 1600) have compressed characteristic and the developer used only affects intensity od compression or actual emulsion speed (measured on ISO standards).
    older emulsions tends to be compressed too, but at higher densites (3-4) so it is extremely hard to make compressed image with them and to print it, of course.

  2. #12

    Join Date
    Jan 2005
    Location
    Pennines
    Shooter
    4x5 Format
    Posts
    146
    If you operate the zone system the N-, N, N+ development along with the altered exposure values is quite a neat way of tweaking the curves.

  3. #13
    dwdmguy's Avatar
    Join Date
    Feb 2009
    Location
    Freehold, NJ
    Shooter
    Medium Format
    Posts
    819
    I may finally have an advantage over you guys....
    I'm a relative novice in the darkroom, only the last year, and I clearly see a different curve using different specific developers.

    FWIW

  4. #14
    Usagi's Avatar
    Join Date
    Apr 2007
    Location
    Turku, Finland. Northern Europe.
    Shooter
    Multi Format
    Posts
    360
    Images
    18
    Quote Originally Posted by keithwms View Post
    Well, CI determines the compression of the tone scale, so if you control that in tandem with control of the degree of compensation, wouldn't that amount to curve control?

    And like I said, some developers and concentrations will affect highlights at a different rate from shadows (as proven by warm water bath stopping), so... isn't that curve control?

    .....

    Maybe I am missing something?
    I mean the shape of the curve. Yes, CI defines compression but CI is just one form of average gradient, thus two different films with complete different curve shape can have same CI.

    Now, having more time to study link I found something that actually shows what I am looking for: The shape of curve can be altered by developer. At least some degree.

    Here's the APX-100 developed in FX-39:


    And here's in Rodinal:


    And Tmax:


    The overall shape of the curve is S with these developers, but with rodinal, the shoulder is much straighten than with FX-39 and TMAX. That is kind of differences I am looking for.

    However, the really interesting is differences of middle tones - 'the straight' section.
    Can it altered to be more unswept, or curved? According to new edition of the Adams's Basic Technique Of Photography Book 2 and various web sites - Yes. Mainly with HC-110 which gives unswept curve for films that usually has S shaped curve.

    So far, it seems that Puts website cannot taken seriously. These all shows that curve shape is not entirely defined by emulsion of the film but developer also has own impact to it.

    But how far we can go and with which film and developers? Can straight charasteristic curve (like curve of TMAX 100) altered to have both, more curved toe and shoulder?


    This is interisting issue, I have calibrated lot of films for ZS, drawn charasteristic curves, studied them etc... But always with one developer + film combo. Never had time or interest to do same test for given film with another developer. Except one case: when I changed D-76 to XTOL, I had to recalibrate developing of some films, but with XTOL the shape of the curve didn't changed.

  5. #15
    Lukas_87's Avatar
    Join Date
    Jan 2008
    Location
    Prague, Czech Republic (Europe)
    Shooter
    35mm
    Posts
    114
    Images
    2
    it is important to not overdevelop too much because you will get high density negatives with shoulder as like the apx100 + rodinal (you can be sure the shoulder IS there but far far away from easily printable range of the negative)
    talking about this - friend of mine never had a problems with printing the lightest areas, never needed preflashing and other tweaks.... why?
    everything on his negatives is straightly printable.... he uses delta 400 + dd-x at most. sometimes tri-x 400 in microphen od neopan 1600. nothing else at all.

  6. #16

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    Quote Originally Posted by Ian Grant View Post
    There's a vast array of low, medium and high contrast
    developers around. Ian
    And any one of them, according to the manor in which
    it is used, will allow for curve alteration. Dan

  7. #17
    ic-racer's Avatar
    Join Date
    Feb 2007
    Location
    Midwest USA
    Shooter
    Multi Format
    Posts
    6,236
    Quote Originally Posted by Nicholas Lindan View Post
    an example, Rodinal produces very low shadow contrast.
    Here is an example of what Nicholas is describing. Same film, two different developers, similar gamma:

  8. #18

    Join Date
    Aug 2005
    Location
    Los Alamos, NM
    Shooter
    Multi Format
    Posts
    2,055
    In many cases, the differences are quite significant. Also note the differences in film speed for the various developers.

  9. #19
    Usagi's Avatar
    Join Date
    Apr 2007
    Location
    Turku, Finland. Northern Europe.
    Shooter
    Multi Format
    Posts
    360
    Images
    18
    Rodinal alters the toe that much! That was new to me. Thank you!
    (actually same information is on the on the chart's of the Foto Import site if I take my eye to the hand and look closer)

    Now I have really something to study and test. Should even do some testing with my mostly used films with rodinal, xtol and pyrocat-hd. Then I will be wiser - I hope.
    Last edited by Usagi; 05-25-2009 at 02:33 PM. Click to view previous post history.

  10. #20
    dr5chrome's Avatar
    Join Date
    Dec 2006
    Shooter
    Medium Format
    Posts
    445
    Images
    12
    How much can you alter the characteristic "curve" with developer?....

    ENORMOUS!

    Mr. Puts is quite wrong, if this is what he meant.
    Its possible what he meant was the "character" of the film is unchanged.

    Regards

    dw




    Quote Originally Posted by Usagi View Post
    The interesting question came to my mind after I ran into this writing at the internet: http://www.imx.nl/photo/Film/Film/Film/page39.html

    According to writer, Erwin Puts, the developer does not have (any) practical effect to the film's characteristic curve.

    This site states exactly opposite:

    "Although I have not made detailed tests, it appears that HC-110 tends to produce an "upswept" characteristic curve with relatively high contrast in highlights (dark areas of the negative, light areas of the picture). With T-Max 100 film in particular, HC-110 produces an upswept curve, with more contrast in the highlights than in the shadows, while Xtol produces a more S-shaped curve (reminiscent of Tri-X Pan), with the most contrast in the midtones."
    I have always thought that developer have and different developers alters the shape of the characteristic curve.

    What is the thruth? Is there some more documented facts about this?

    Have to say that I have not never run sensitometric tests to same film with different developers... Perhaps I should do so.
    Last edited by dr5chrome; 05-25-2009 at 03:20 PM. Click to view previous post history.

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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