Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,445   Posts: 1,569,889   Online: 1202
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 21
  1. #11
    dwross's Avatar
    Join Date
    Feb 2004
    Location
    Oregon Coast
    Shooter
    Multi Format
    Posts
    847
    Hi Mustafa,
    Nice to hear from you again. You always spark great discussions and you've gotten some really sound advice here already.

    This one has me a bit confused, though. There are two reasons to pursue historical information: 1) as a 'purist' whose primary interest is basically in technical archeology - facts for the sake of fact alone, and 2) as a creator of art who yearns for the look of an extinct product. You can be both, of course, but the direction you start your investigations is very much determined by which is more important to you. You say that your friend has tried pan x with a monobath, so that hints that he may be looking from an artist's viewpoint.

    Kirk is spot-on about the costs involved if you hire an outside lab. Ouch! Really. Keith is smart to point out the pitfalls of comparing current emulsions with old, even if they carry the same name. If art is the primary goal (and, of course, pure science can always follow later), perhaps you and/or your friend should learn plain, old-fashioned emulsion making. It might seem like a backdoor approach, but it is after all how it all started. Reverse 'reserve engineering' if you will.

    Best,
    d

  2. #12
    dwross's Avatar
    Join Date
    Feb 2004
    Location
    Oregon Coast
    Shooter
    Multi Format
    Posts
    847
    I see I should have taken a peek at what was posted while I typed. There is indeed a third reason - the entrepreneur. If your friend is serious, I evenly more strongly advise first learning a bit about the basics of emulsions. It will serve him well in the long run.

  3. #13
    Mustafa Umut Sarac's Avatar
    Join Date
    Oct 2006
    Location
    İstanbul - Türkiye
    Shooter
    35mm RF
    Posts
    3,950
    Images
    108
    I think We are sniffing the air like an old grey wolf to find a product who lost his way

  4. #14

    Join Date
    Jan 2010
    Location
    Massachusetts
    Shooter
    4x5 Format
    Posts
    108
    I have the 55 reagent or something very close to that reasonably well analyzed. The Haist book is also an excellent monobath treatise which does touch upon the reagent without being specific. There is no specific 55 related patent that I know of after a fairly intense review. At least one suitable off-the-shelf emulsion has been identified that could be used with the reagent - but - we do not have a handle on the DTR kinetics yet, which are determined by, among other things, the receiver sheet.

    That's the part where I could use some help.

    Much more on http://new55project.blogspot.com

  5. #15
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,362
    Images
    65
    The two main ingredients that I remember are KOH and Carboxy Methyl Cellulose.

    PE

  6. #16

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Quote Originally Posted by Photo Engineer View Post
    The two main ingredients that I remember are KOH and Carboxy Methyl Cellulose.
    Neither of which would show it in a gas chromatographic analysis.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  7. #17
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,362
    Images
    65
    Correct Kirk. It would take a wet chemical analysis for organics and inorganics to really do the job right!

    PE

  8. #18

    Join Date
    Jan 2010
    Location
    Massachusetts
    Shooter
    4x5 Format
    Posts
    108
    Yes KOH is fine and you can use LiOH - either one with a pH of 11 when all is mixed. Cellulose thickener is to regulate spread rate and thickness. Other materials such as silica have and can be used.


    If you are familiar with Haist you will recognize this:


    from the 55 pod MSDS

    POTASSIUM HYDROXIDE 1-5 001310-58-3
    LITHIUM HYDROXIDE MONOHYDRATE 1-5 001310-65-2
    T-BUTYLHYDROQUINONE 1-5 001948-33-0
    SODIUM SULFITE ANHYDROUS 1-5 007757-83-7
    SODIUM THIOSULFATE PENTAHYDRATE 5-10 010102-17-7

    I am up to my ears in what are essentially monobaths. But the above used alone, don't expect a good cleared negative. The receiver sheet construction, nucleating properties and absorption of dissolved silver appear to be important, and while there are many patents and descriptions of the receiver sheet, none are specific (or say they are) to 55.

    Please someone out there must have some knowledge of the production and preparation of the older receiver paper, the stuff that needs coating. If you do, I would gladly compensate expenses as this part of our project is proving costly, time consuming, and tying up resources as we cast about.

    The rest is straightforward. If the economics are right, and we follow through (after knowing receivers) I am quite sure we will have a high quality 4X5 and maybe 8X10 field processable negative system with some kind of positive as a remnant, at least. It can be made as complicated as we like, but this isn't actually very hard as long as we remember we are not trying to make 55.

    Thanks

  9. #19
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,362
    Images
    65
    Bob;

    It needs a thickener to make it spread properly. IDK how much, but a little bit of CMC goes a long way.

    PE

  10. #20

    Join Date
    Jun 2003
    Shooter
    Multi Format
    Posts
    16,821
    Images
    24
    Quote Originally Posted by keithwms View Post
    P.S. also note that the current (aerial) panatomic-x is likely not the same thing as what we have in type 55. All I have said (and others too, if I remember correctly), is that there appears to be a close resemblance. But the aerial stuff probably differs in terms of spectral sensitivity.... and that may have implications for how it is best developed. I'd expect aerial to be considerably more red sensitive.
    aero film
    had red sensitivity
    to cut through haze ..
    pan x wasn't quite like that ...
    but aero x from mr foto1 is pretty cheap


    john

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