Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,276   Posts: 1,534,783   Online: 823
      
Page 3 of 3 FirstFirst 123
Results 21 to 26 of 26
  1. #21

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by Roger Hicks View Post
    Dear Eric,

    Fair enough. But Kallitypes (like all printing-out processes) are self-masking and were traditionally printed by inspection. As long as you have plenty of contrast, you should be OK.

    Roger
    True kallitype, based on ferric oxalate, has very little self-masking.

    Vandyke Brown (VDB), which some people lump in as a kallitype process, is self-masking. VDB is based on ferric ammonium citrate, which gives rather different image qualities compared to kallitype.

    Practice today is to treat kallitype and VDB as separate processes.

    Sandy King

  2. #22

    Join Date
    May 2006
    Location
    Northern Aquitaine
    Shooter
    35mm RF
    Posts
    4,913
    Quote Originally Posted by sanking View Post
    True kallitype, based on ferric oxalate, has very little self-masking.

    Vandyke Brown (VDB), which some people lump in as a kallitype process, is self-masking. VDB is based on ferric ammonium citrate, which gives rather different image qualities compared to kallitype.

    Practice today is to treat kallitype and VDB as separate processes.

    Sandy King
    Dear Sandy,

    Sure, I accept their difference, but how can you have any printing-out process that is not inherently self-masking? You have far more experience than I so I would be interested to know how and why they differ in this respect.

    Cheers,

    Roger
    Free Photography Information on My Website
    http://www.rogerandfrances.com

  3. #23

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by Roger Hicks View Post
    Dear Sandy,

    Sure, I accept their difference, but how can you have any printing-out process that is not inherently self-masking? You have far more experience than I so I would be interested to know how and why they differ in this respect.

    Cheers,

    Roger
    True kallitype is not a printing out process. Where did you read that it was? It is primarily a DOP process and if any source states otherwise it is in error.

    Albumen, Argyrotype, salted paper and VDB are primarily POP processes.

    Some methods of palladium printing are POP, others are DOP.

    With most of these processes working conditions of high RH accentuate the POP characteristics,

    Sandy

  4. #24

    Join Date
    May 2006
    Location
    Northern Aquitaine
    Shooter
    35mm RF
    Posts
    4,913
    Quote Originally Posted by sanking View Post
    True kallitype is not a printing out process. Where did you read that it was? It is primarily a DOP process and if any source states otherwise it is in error.
    Dear Sandy,

    That's the answer. Source forgotten, but obviously wrong. Thanks.

    Cheers,

    Roger
    Free Photography Information on My Website
    http://www.rogerandfrances.com

  5. #25

    Join Date
    Dec 2005
    Location
    Hollis, NH
    Shooter
    35mm
    Posts
    732
    Images
    3
    Quote Originally Posted by Akki14 View Post
    Is there some chart I'm unaware of that tells you times based on density? If there was such a chart then I could see a densitometer being useful but for alt process stuff, experience and testing for yourself is the best teacher. If there was such a chart it'd have to incorporate how far from the bank of UV tubes and how powerful the wattage and how many tubes (possibly) etc. A split back frame for printing-out-processes would be infinitely more useful than an expensive gadget and experience will eventually come to you in the long run from actually doing the process rather than reading off pretty little numbers.

    From my experience with using a facial tanner unit with a bank of UV bulbs, exposures take a very long time for my cyanotypes - give me a bright sunny day over the UV box any day. It can mean the difference between 45minutes in front of the box and a maximum of 20minutes outside on a full sunshine day.
    Hi Heather,
    I wasn't thinking of using the densitometer to determine exposure for your print. I was thinking of using the densitometer to measure the density of highlights on the negative so you can determine the development timed that yields a contrast range appropriate for your print process.

  6. #26

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by Roger Hicks View Post
    Dear Sandy,

    That's the answer. Source forgotten, but obviously wrong. Thanks.

    Cheers,

    Roger
    Roger,

    To be fair, none of these processes are completely DOP or POP, in the sense that a modern bromide paper is DOP. Even with DOP kallitype and pt./pd. you have a whisper image that may impart some degree of self-masking, and with most POP processes there is some degree of intensification of the image in post-exposure wet processing.

    That is why I used the term "primarily DOP" to describe true kallitype.

    Sandy

Page 3 of 3 FirstFirst 123


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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