Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,879   Posts: 1,520,393   Online: 1016
      
Page 1 of 3 123 LastLast
Results 1 to 10 of 26
  1. #1

    Join Date
    Jun 2005
    Location
    Plymouth. UK.
    Shooter
    Multi Format
    Posts
    1,399
    Images
    3

    Homebrewed Colour Processes.

    I found this link on the web. http://www.opie.net/orphy/photo/dr/wkft-e6.html

    I wouldn`t have thought it would be worth bothering with over commercial film processing. My apologies if someone has already posted this or similar before.

  2. #2
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,911
    Images
    65
    Keith;

    The first developer is wrong and the color developer is wrong. This will risk color shifts and crossover not to mention possible high Dmin values. I have seen this page here several times and have reminded people that the first developer uses HQ mono sulfonate, and the color developer contains Etylene Diamine.

    PE

  3. #3

    Join Date
    Jun 2005
    Location
    Plymouth. UK.
    Shooter
    Multi Format
    Posts
    1,399
    Images
    3
    Quote Originally Posted by Photo Engineer View Post
    Keith;

    The first developer is wrong and the color developer is wrong. This will risk color shifts and crossover not to mention possible high Dmin values. I have seen this page here several times and have reminded people that the first developer uses HQ mono sulfonate, and the color developer contains Etylene Diamine.

    PE
    Thanks for pointing that out. To save time trawling through the various threads and post, what is the proper formula for the 1st and colour developer?

  4. #4
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,186
    Images
    148
    Ron, it may be wrong but they work. There have been various alternative formulae published over the years, I used one from the BJP for a while, and I know a large commercial lab in Birmingham made up all their own colour chemistry from similar formulae, ironically they were just a 30 second walk from Hogg's the chemical supplier mentioned. They bought from another supplier, Hoggs moved later to almost opposite).

    When Hogg's stopped selling Photo-chemicals I bought the entire sock Rayco have gone as well.

    Munns Brothers was the lab in question, they were a large lab taking C22/E4 then later C41/E6 from various retail outlets across the Midlands (UK), they had very able chemists and saved a fortune compounding their own chemistry, I don't know which formulae they used but I do know someone who would. The company closed the lab in the early 90's but only after diversifying becoming one of the largest operators of high street Minilabs in the UK, they are still canny, and last I heard were using Fuji Frontier machine with Tetenal chemistry, which is widely regarded as the best independent manufacturer.

    Ian

  5. #5
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,911
    Images
    65
    Ian;

    That formula may work with one film or brand of film but not another. I have seen one set of chemistry vary even within the same product across emulsion numbers. But, all of the products were ok in the standard release test.

    Among other things, HQMS is milder and can reach the bottom layer to start development in a more uniform fashion overall and therefore it minimizes crossover and color shifts between slow and fast films. It was selected for this to work properly at 100 F.

    I merely advise caution. Corrected formulas that were authentic were published about 15 years ago in a special edition of Darkroom Techniques. I have mislaid my copy or I would give that data. I turned in my actual formulary when I retired.

    So, I would hesitate before I saw a direct comparison with this and authentic formulas.

    PE

  6. #6
    darkosaric's Avatar
    Join Date
    Apr 2008
    Location
    Hamburg, Germany
    Shooter
    Multi Format
    Posts
    1,506
    Did anyone drop an email to original author of text (Derek Watkins)? Is he active here on apug?

  7. #7

    Join Date
    Jun 2005
    Location
    Plymouth. UK.
    Shooter
    Multi Format
    Posts
    1,399
    Images
    3
    Quote Originally Posted by darkosaric View Post
    Did anyone drop an email to original author of text (Derek Watkins)? Is he active here on apug?
    Is he? I was not aware of that. Perhaps you could send him a PM.

  8. #8
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,186
    Images
    148
    I have to say Ron, I don't know where the Watkins formulae comes from, but I've known people who've used it with no problems regardless of film stock.

    The formulae I've used have all been attributed to Ernst Gehret, who appears to have been an extremely able photo-chemist specialising on colour processing, he published a wide variety of alternative formulae from the 50's right through to E6, C41, RA-4, I don't know much about him but his formulae have always worked perfectly.

    Ian

  9. #9

    Join Date
    Jun 2005
    Location
    Plymouth. UK.
    Shooter
    Multi Format
    Posts
    1,399
    Images
    3
    PE, I googled for Hydroquinone-monosulfonate, but I am still none the wiser of how it works compared to hydroquinone. I also came across chlorohydroquinone. I guess that they are all kind of related components, but have a very different working effect for developing. Perhaps you could explain the special properties of these components compared to regular hydroquinone.

  10. #10
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,911
    Images
    65
    Ian;

    The article I refer to was probably by Pat Dignan who repudiated earlier formulations when he changed to the more nearly correct version. In the same magazine was a comparison of 5 different C-41 scratch mixes with the authentic Kodak formulation that showed similar problems.

    In the group I worked in, we often ran 4 runs / day of film or paper in up to 12 developers per run. These were variations such as seen in the reference article. This resulted in literally thousands of test results comparing speed, curve shape, color reproduction, grain and sharpness. After years of that I must stand by what I said. Unless you show it to me with a fast and slow film from Kodak and Fuji side by side with the authentic E6 and we look at all factors, I believe that you will see random anomalies that may cost you some photos.

    For all we know, the article itself is biased only showing one film and within that only the good slides. IDK. No accusations except the unknown, which to me as a photo engineer makes me wish to make you all aware of the situation.

    Other than that, do what you wish.

    PE

Page 1 of 3 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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