Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,906   Posts: 1,555,858   Online: 861
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 27

Thread: Ziatype - Help!

  1. #11
    cjarvis's Avatar
    Join Date
    Sep 2002
    Location
    Maryland
    Shooter
    Large Format
    Posts
    183
    Images
    26
    For Kid Finish you don't need the Tween 20.

  2. #12

    Join Date
    Jul 2003
    Location
    Texas
    Shooter
    Multi Format
    Posts
    3,576
    Images
    27

    Update - Observations After Another Days Attempt

    Did a couple of more prints yesterday (Sat) and thought I would share what I found. First, I will agree a dedicated light source is better than the sun, since the chemicals I have are over a year old and I haven't had the chance to build one I figured I would a least use what I have ... so for now it's the sun as the light source.

    1st print - Issues do not think it was dry enough before I put in the contact printer and exposed it. Was partly cloudy, so light source was not constant.

    The reason I don't think the coating was dry enough - when it was exposed with enough light, it never completed development - DMAX on the outer edges of the coated space was very good, but the remainder of the print was not..best it did was a strong gray color. Question if this was due to uv light or once the print has developed to a point is it not possible to obtain good DMAX? Since the sun was dancing between the clouds.

    2nd print - good DMAX, print looked much better - other than I left it out too long. Overall print was dark, but coating area outside of negative was amazing how black it was.

    Did change negative - see the Perry Church in my personal gallery, this one I know has a good range and it printed much better...even the first one looked better.

    So now the question, How do you kow the exposure is correct by looking at the negative/paper combo in the contact printer?
    Mike C

    Rambles

  3. #13

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by photomc
    Question if this was due to uv light or once the print has developed to a point is it not possible to obtain good DMAX? Since the sun was dancing between the clouds.


    So now the question, How do you kow the exposure is correct by looking at the negative/paper combo in the contact printer?
    Mike,

    Exposing with UV light is no different than exposing with regular light. With an ideally exposed and developed negative the outer border should reach maximum density in about the same time as the deepest shadows in the print. That is not apparently happening in your case, suggesting that the negative is over exposed. If the negative is overexposed but has the right contrast range you can simply expose more and the print should look fine. However, and I suspect this is the case with your negative, if the negative is not only over exposed but under developed the print will lack contract because the shadows and highlights print in about the same time, resulting in a muddy, flat look. You need to either changer to a negative with greater contrast or increase the contrast of your process by adding some dichromate.

    Sandy

  4. #14

    Join Date
    Jul 2003
    Location
    Texas
    Shooter
    Multi Format
    Posts
    3,576
    Images
    27
    Sandy, either I'm not understanding or ask the question incorrectly - what I was wondering is, how can you tell if the print has enough exposure WHILE you are exposing it. In other words, with the neg/paper/print frame in the sun, how do I know when it is enough exposure? Did some more this morning with another negative that I think has more contrast, and still guessed the exposure but think I am much closer. Posted it in the Experimental Gallery.

    Thanks for your help..It does help, sometimes these things come easier for some than others.
    Mike C

    Rambles

  5. #15

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by photomc
    Sandy, either I'm not understanding or ask the question incorrectly - what I was wondering is, how can you tell if the print has enough exposure WHILE you are exposing it.

    Mike,

    In my experience the visual reference you get with POP processes during exposure is not adequate to accurately predict when the print has enough exposure. There are always changes that take place durng processing and dry down that affect the final look so you really never know if exposure was accurate until the print dries and you can look at in normal viewing light.

    Sandy

  6. #16

    Join Date
    Jul 2003
    Location
    Texas
    Shooter
    Multi Format
    Posts
    3,576
    Images
    27
    Thanks Sandy, keep reading about looking at the print during development and was wondering what everyone was using as a reference point. The prints I did today, exposure was base on the how dark the print looked - ie when the shadows (thinner parts of negative) were no longer yellow color - it was ready.

    Have noticed the changes you referred to such as dry down, not to mention wash and citric acid bath...now those are changes.
    Mike C

    Rambles

  7. #17
    colrehogan's Avatar
    Join Date
    May 2004
    Location
    St. Louis, MO
    Shooter
    Large Format Pan
    Posts
    2,016
    Blog Entries
    3
    Images
    16
    Mike,
    I take my printing frame inside the house and open one side of it to evaluate how the process is going. I don't know how else to gauge how the printing is proceeding, as I don't have enough experience of the process myself (I've only done maybe 10 prints) and I also use the sun. I am considering getting/building a UV lightbox soon. I want to do printing more often than on sunny weekends.
    Diane

    Halak 41

  8. #18

    Join Date
    Apr 2004
    Location
    Bezerkeley, CA
    Posts
    92
    Images
    1
    Checking a print during exposure is only a guide for those first few test prints for me in any process as they all print out to some extent and learning to read the “whisper” takes experience within the process. When I started Zia I would print 2 maybe three at different exposure times and let them dry down and now that I know how much it typically dries down I usually do only one , then for subsequent prints I don't check the exposures for a couple reasons...I fear that opening the frame during exposure of a humidity controlled process will allow the humidity in the paper to change which I believe will lead to inconsistent results and as Sandy stated there are too many variables to attempt to truly nail the exp based on looking at the print prior to dev and dry down.

    You need to be consistent working with humidity controlled processes because everything you do will affect the printing out of the paper as well as the densities you’re able to achieve in the final print. I learned this the long and hard way.

    BTW, I chose to use Potassium Chlorate for contrast control over the Dichromate.

    Happy Days
    Mark
    You can't be lost if you don't care where you are.

  9. #19

    Join Date
    Sep 2002
    Shooter
    Large Format
    Posts
    4,530
    Les wrote an article on dry down, it works for pt/pd too.....

    I have my own method, but his is just as good.

  10. #20

    Join Date
    Feb 2004
    Location
    Iowa
    Shooter
    Multi Format
    Posts
    829
    Images
    7
    Quote Originally Posted by donbga
    Zias depend on a a paper humidity of at least 50%. Use a sheet of Mylar underneath the paper to act as a damn to prevent loss of humidity during exposure.
    I'm gathering all the supplies to try my hand at Zias. Where can I get mylar sheets?

    Thanks,
    Matt

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