Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,769   Posts: 1,484,218   Online: 938
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 31

Thread: Kodak Monobath

  1. #11

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,547
    Monobaths do find limited use in specialized applications, ie the Poloroid camera is based on a monobath. But for general purpose use they have no real advantage. A monobath depends on the control of two competing kinetic reactions; development and fixation. Unless the two processes are finely controlled the resultant images will be less than optimal. Monobaths became only practical with the use of Phenidone or its derivatives. The negative produced by a monbath differs from a conventional one in several ways. For those that are curious get Haist's book as he explains the differences fully. For example the image of a monobath negative is limited to the surface of the emulsion and does not penetrate very much into its interior. This acts to increase acutance.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  2. #12

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,272
    It is also quite grainy

  3. #13

    Join Date
    Feb 2012
    Location
    Penfield, NY
    Shooter
    35mm
    Posts
    897
    Quote Originally Posted by Gerald C Koch View Post
    Monobaths do find limited use in specialized applications, ie the Poloroid camera is based on a monobath.
    "the Poloroid camera is based on a monobath" should say "the Poloroid B&W peel-apart system is based on a monobath"

    I know monobaths were used in some early B&W reconnaissance satellites.

  4. #14
    Vaughn's Avatar
    Join Date
    Dec 2006
    Location
    Humboldt Co.
    Shooter
    8x10 Format
    Posts
    4,552
    Images
    40
    Quote Originally Posted by Michael R 1974 View Post
    It is also quite grainy
    I guess Polaroid Type 55 was the exception...the negs are beatutiful!
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  5. #15

    Join Date
    Jul 2008
    Location
    Maastricht
    Shooter
    Multi Format
    Posts
    411
    Images
    5
    But no one has actually experience with the Kodak Monobath? As my question was? I don't mind the talking that was going on. But I geuss I will have to buy 6 bottles of 500ml and give it a try. See how it behaves and such.

    My interest is purely curiosity. Do it once or twice and probably forget about it. But it would be nice to go out on a trip with Harman direct positive paper and be able to process it on the spot on step. Not that I have any specific plans yet
    Reality is whatever stays when you stop believing in it.
    darkroomninja.blogspot.com

  6. #16
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,966
    Images
    148
    Quote Originally Posted by Prof_Pixel View Post
    "the Poloroid camera is based on a monobath" should say "the Poloroid B&W peel-apart system is based on a monobath"

    I know monobaths were used in some early B&W reconnaissance satellites.

    Neville Maude's article "The Rise & Fall of the Monobath" in the BJP Annual (can't remember off hand if it was 1972 or 76) states that the US research was sponsored by the US Air force and they were working with 40" wide film. H.S. Keeling an was using Phenidone based PQ monobaths as soon as it was commercially available in the early 1950's.

    In the UK a commercial monobath "Develofix" was available and reviewed in 1913 by the BJP. Mees and Sheppard a pair of chemists in the UK just out of University worked on Monobaths they pointed out that development was deep in the emulsion but that the effects of the solvent (thiosulphate) were greatest at the surface.

    I've a around 30+ pages of notes on Monobaths as well as quite a few Patents and articles and it would be useful to collate it all, unfortunately I have little time at the moment as I've just moved house and much of my stuff is in storage.

    As Vaughn points out Monobaths are capable of excellent fine grain and sharpness, and my experience is with the balance right there's no loss in Dmax.

    Ian

  7. #17

    Join Date
    Feb 2012
    Location
    Penfield, NY
    Shooter
    35mm
    Posts
    897
    I remember using (and selling) a monobath in the late '50s or early '60s. Seems to me it was called Unibath. It worked OK, but the shelf life was short.

  8. #18
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,966
    Images
    148
    Quote Originally Posted by Prof_Pixel View Post
    I remember using (and selling) a monobath in the late '50s or early '60s. Seems to me it was called Unibath. It worked OK, but the shelf life was short.
    Unibath CC1 (normal films), CC2 (high speed films slight push) and CC3 (papers) Introduced 1959. by the Cormac Corporation of New York. Evidently the CC3 was useless with British papers and was unsuccessful. (It's in my notes)

    Ian

  9. #19
    AgX
    AgX is offline

    Join Date
    Apr 2007
    Location
    Germany
    Shooter
    Multi Format
    Posts
    7,481
    Quote Originally Posted by Prof_Pixel View Post
    "the Poloroid camera is based on a monobath" should say "the Poloroid B&W peel-apart system is based on a monobath"

    I know monobaths were used in some early B&W reconnaissance satellites.
    All diffusion transfer-reversal systems based on silver-salt use monobath processing. This includes the former Polaroid integral b&w system.

  10. #20

    Join Date
    Feb 2012
    Location
    Penfield, NY
    Shooter
    35mm
    Posts
    897
    Quote Originally Posted by AgX View Post
    All diffusion transfer-reversal systems based on silver-salt use monobath processing. This includes the former Polaroid integral b&w system.
    Interesting enough, it doesn't apply to the integral picture unit Kodak Instant/Fuji Instax films

    I don't remember ever seeing an integral picture unit B&W film from Polaroid.

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