Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,283   Posts: 1,534,938   Online: 900
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 31
  1. #11

    Join Date
    Apr 2006
    Location
    Kyle, Texas
    Shooter
    Large Format
    Posts
    15
    A visit to the Google Patent search on this provides three other related patents:

    http://www.google.com/patents?q=5683...Search+Patents

  2. #12
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,242
    Images
    148
    There have been specific Patents for spraying photographic emulsions, I have some references back in the UK. Unfortunately searching the UK system online is almost impossible.

    Ian

  3. #13
    dwross's Avatar
    Join Date
    Feb 2004
    Location
    Oregon Coast
    Shooter
    Multi Format
    Posts
    803
    I kinda figured your idea came from a source like this. What's important to remember is that a silver gelatin photographic emulsion isn't just silver suspended in gelatin. The second a solution of silver nitrate hits a solution of gelatin and bromide or chloride salt, the fundamental nature of the solution changes. Think the difference between vegetable oil and mayonnaise. The solution in the patent, with its plasticizers and 'surface active agents', including lecithin, held at a very high (for most emulsions) temperature, is different enough from a silver gelatin photographic emulsion as to make any comparison essentially meaningless.

  4. #14
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    I agree totally with what Denise has posted. I would like to add that some of this work cited uses fish gelatins which are totally different than pig or bovine gelatins. Among other things, fish gelatins do not chill set and must have other ingredients added to allow them to solidify, or the water must be removed.

    PE

  5. #15
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,242
    Images
    148
    Back in the 70's I photocopied a section from a book on emulsion coating, there was a short piece on spray coating, I think it was possibly E.J.Wall. I came across the pages again this Easter, I should be able to find them when I'm back in the UK later this month, along with the Patent references.

    Ian

  6. #16

    Join Date
    Aug 2005
    Location
    Earth
    Shooter
    Multi Format
    Posts
    1,560
    Quote Originally Posted by Photo Engineer View Post
    Then please tell us about it!

    PE
    ?

    They have been used for example by Lockheed Martin (sort of... companies merge and change names...) They had 30 x 30 ft “camera” room cameras where oversized materials were exposed. The lens was set in the wall between the "camera obscura" and the "stage" room where the original was located and illuminated.

    These rooms served the dual purpose of both camera and enlarger; once the negative was ready, the process was reversed and light forced through the negative was sent through the lens and onto large metal sheets or Masonite boards sensitized with their own liquid photographic emulsion. I am pretty sure these were sprayed on, (I could look at the pictures again) but I am sure the emulsion itself could also be applied by other methods; in fact, later on, for smaller scale work, it was.

    Ray
    Last edited by Ray Rogers; 10-03-2010 at 11:05 AM. Click to view previous post history.
    Be free of all deception, Be safe from bodily harm
    Love without exception, Be a saint in any form
    (Patti Smith)

  7. #17
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,242
    Images
    148
    Emulsions where sprayed for engineering uses, often a photographic template was enlarged on to metals before cutting, the technique was called photo-lofting. One reason why dried powder emulsions were used was they had good long term storage without refrigeration. Any additional base fog was irrelevant.

    Ian

  8. #18
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    Ray;

    Do you have a reference?

    Kodak had such a setup but it used standard coated materials cut to size for the job as follows:

    Full Darkroom | Camera | Studo and Darkroom

    The film was inserted on the left and exposed and processed in that room. The film was then reinserted in the camera which then projected the scene back into the studio onto paper which was then processed. I spent some time in this pair of rooms being given a complete tutorial on its use by the designers. It was located in Kodak Office and is now long gone.

    PE

  9. #19

    Join Date
    Aug 2005
    Location
    Earth
    Shooter
    Multi Format
    Posts
    1,560
    Quote Originally Posted by Mantinieri View Post
    I found that someone either used or, at least, experimented already with such technique. I would appreciate if some of the exports could elaborate on the topics and explain why essentially nobody is using it any more.
    May I Speculate?

    Every coating method has (or should have!) its strong point.
    Unfortunately, they also have their own weak points.

    Spraying was good because it was a simple, manual method that could be used to make good coatings on large surfaces using equimpment and skill sets that already existed, while other methods were not, could not or did not.

    The assumption that nobody is using it any more might be slightly anemic.
    Both I and PE know people who use it successffuly to make good coatings...
    Ian has used it, and well there must be others out there....

    Perhaps a better question would be:

    For what might spray coating be considered the method of choice?

  10. #20
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,242
    Images
    148
    Quote Originally Posted by Ray Rogers View Post

    Perhaps a better question would be:

    For what might spray coating be considered the method of choice?
    An object that can't be laid flat, or a 3D object.

    Ian

Page 2 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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