Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,514   Posts: 1,543,644   Online: 1132
      
Page 47 of 50 FirstFirst ... 3741424344454647484950 LastLast
Results 461 to 470 of 493
  1. #461

    Join Date
    Nov 2004
    Location
    The highest state
    Shooter
    Multi Format
    Posts
    1,916
    Quote Originally Posted by Ken Nadvornick View Post
    I've wondered exactly the same thing. And a common sense guess isn't difficult...



    [Edit: Ooow... I just had an evil thought pop into my head... You don't think... Naw... Hmm...]

    Nah, the buyer is in the U.S.....

  2. #462
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,012
    Images
    65
    On the topic of dye bleach.......

    Henry Wilhelm knows nothing about DB vs Chromogenic materials. The DB process is much more dangerous to use than any chromogenic prcess. DB materials were never possible to prepare with real camera speeds. It would take a family of shiftable dyes to make this possible. And finally, the grain in DB is at its maximum in medium to low density areas making the images you do get rather unpleasant. Kodak had a DB print process ready to go and its introduction date was 8 Dec 1941. It was called Azochrome.

    PE

  3. #463

    Join Date
    Nov 2004
    Location
    The highest state
    Shooter
    Multi Format
    Posts
    1,916
    Quote Originally Posted by Photo Engineer View Post
    Well, I have tried to get the Kodak data sheet with process and formula details. It seems that Kodak took it down. Using wayback.com, I am informed that there is a block on that information. It is apparently unavailable. Therefore, unless someone has the PDF for us, the patent is the only source of information.

    And if no one is interested in trying to process Kodachrome, my offer of help still stands. I'm here. I'm not trying to herd cats.. I'm saying if you are hungry, there is food in the bowl.
    I'm willing to be a liaison for this, do you know anyone at EK that has either an operator's manual or maintenance manual for a K-Lab? I assume programing is windows based....

    You can PM me the info if need be...

    Some additional resources:

    http://www.apug.org/forums/forum43/6...rocessors.html

    http://www.kodak.com/global/en/consu...bs/index.shtml

    I also just wrote Richard Mackson who invented the K-Lab and was senior business and technology associate for Kodak from 1996-2009 to see if he has a line on manuals and any other info on his baby....I'm trying folks, that's best any of us can do.
    Last edited by PKM-25; 08-29-2013 at 05:37 PM. Click to view previous post history.

  4. #464
    Ken Nadvornick's Avatar
    Join Date
    Mar 2005
    Location
    Monroe, WA, USA
    Shooter
    Multi Format
    Posts
    3,285
    Images
    48
    Quote Originally Posted by Photo Engineer View Post
    I'm not trying to herd cats.. I'm saying if you are hungry, there is food in the bowl.
    (Compliments! Great phrase reversal!)

    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  5. #465
    Ken Nadvornick's Avatar
    Join Date
    Mar 2005
    Location
    Monroe, WA, USA
    Shooter
    Multi Format
    Posts
    3,285
    Images
    48
    Quote Originally Posted by PKM-25 View Post
    I assume programing is windows based....
    Now there's a non-organic chemistry angle that, if the timing were right and there was a need, I might be able to help out with...

    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  6. #466
    Prest_400's Avatar
    Join Date
    Jan 2009
    Location
    Spain
    Shooter
    Med. Format RF
    Posts
    543
    Quote Originally Posted by Photo Engineer View Post
    On the topic of dye bleach.......

    Henry Wilhelm knows nothing about DB vs Chromogenic materials. The DB process is much more dangerous to use than any chromogenic prcess. DB materials were never possible to prepare with real camera speeds. It would take a family of shiftable dyes to make this possible. And finally, the grain in DB is at its maximum in medium to low density areas making the images you do get rather unpleasant. Kodak had a DB print process ready to go and its introduction date was 8 Dec 1941. It was called Azochrome.

    PE
    THanks for clarifying PE.
    So DB was more inconvenient and dangerous (the bleach). And I can imagine that the commonality of Chromogenic between film and print materials were more economic on R&D and production due to commonality.
    Also, as of quality of image and longevity; Current Chromogenic material must be quite advanced. I wonder if much R&D is put into it, even if RA4 paper the most used and produced of the family of photographic processes. Many claims of inkjet (pigment inks) being better, but that is out of this forum and photographic process scopes...

    Back to topic. As of retrieving the PDF data, isn't there any contact at Kodak, ex-Kodak, labs, that have the information?
    The OZ EK retiree of the coating machine was trying to do some color, words about kodachrome were spread and nothing since.
    Probably there is a few people interested in it but out of internet's reach (thinking of the latter). I do recall PE saying that many of his colleagues weren't interested anymore but perhaps there are a few around who could be with a little push.

  7. #467
    AgX
    AgX is offline

    Join Date
    Apr 2007
    Location
    Germany
    Shooter
    Multi Format
    Posts
    8,597
    Quote Originally Posted by Photo Engineer View Post
    Kodak had a DB print process ready to go and its introduction date was 8 Dec 1941. It was called Azochrome.
    Agfa did the same decades later and failed commercially too.

  8. #468
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,012
    Images
    65
    I have to scream this from the rooftops I guess.

    POS-POS print systems have an inherent flaw. You are basically multiplying the slope of one curve by the slope of the other curve, (original slide x print material) to get the final dupe image. If your original has a perfect capture and a slope of 0.3, and if the print material also has the same slope, the result is a slope of 0.09, which is a reduction in contrast. This is why you must use masks to adjust contrast and masks to adjust color.

    No pos-pos system without these masks has ever been a big success. Thus, high end labs or printers use masks and get superb prints but at a high cost in time and materials. So, most simple pos-pos printers have failed. Or, they had commercial difficulties.

    I know Henry personally and we talked for about 3 hours on his last visit to Rochester. He is avid about what he does, but just like me, neither of us is always right.

    PE

  9. #469

    Join Date
    Nov 2005
    Location
    San Clemente, California
    Shooter
    Multi Format
    Posts
    1,088
    Quote Originally Posted by Photo Engineer View Post
    ...Henry Wilhelm knows nothing about DB vs Chromogenic materials. The DB process is much more dangerous to use than any chromogenic prcess. DB materials were never possible to prepare with real camera speeds...Kodak had a DB print process ready to go and its introduction date was 8 Dec 1941. It was called Azochrome...
    Henry does know about how the permanence of dye bleach compares to chromogenic's, but not necessarily about use safety or designing a process. He also knows about Azochrome. See pages 25 through 29 of his book:


    He never proposed, to my knowledge, a camera-speed dye bleach material. Mostly he opined (to use a recently popular word) that Cibacolor should have been introduced to print from chromogenic negatives.

    Quote Originally Posted by AgX View Post
    Agfa did the same decades later and failed commercially too.
    Yes, that's in the same book pages too.


    Quote Originally Posted by Photo Engineer View Post
    ...POS-POS print systems have an inherent flaw. You are basically multiplying the slope of one curve by the slope of the other curve, (original slide x print material) to get the final dupe image. If your original has a perfect capture and a slope of 0.3, and if the print material also has the same slope, the result is a slope of 0.09, which is a reduction in contrast. This is why you must use masks to adjust contrast and masks to adjust color.

    No pos-pos system without these masks has ever been a big success. Thus, high end labs or printers use masks and get superb prints but at a high cost in time and materials. So, most simple pos-pos printers have failed. Or, they had commercial difficulties.

    I know Henry personally and we talked for about 3 hours on his last visit to Rochester. He is avid about what he does, but just like me, neither of us is always right...
    I'm not so sure he was wrong that a dye bleach negative paper like Cibacolor would have been much better than the Ektacolor/Fujicolor versions we've had to live with. Especially versions sold in the decades between when Ciba-Geigy decided against marketing it and 1993 when the book was released.

    My long-term use of and love for Kodachrome was entirely centered around projecting it, both stills and motion pictures. Direct prints from reversal films, whether Kodachrome or other transparencies, were never capable of duplicating that viewing experience. I didn't try forcing them to.

  10. #470
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,012
    Images
    65
    There are many schools of thought on the method for testing color products. You will note that the GEH sample was kept in the dark in their facility at optimum temperature and humidity, so this proves nothing. Real world samples are what count. I have color negs prints from the '50s and they survived just fine.

    Color reproduction from a pos-pos system is different than the same work from neg-pos. The latter will win hands down.

    PE



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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