Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,536   Posts: 1,544,234   Online: 723
      
Page 6 of 16 FirstFirst 123456789101112 ... LastLast
Results 51 to 60 of 160
  1. #51
    David A. Goldfarb's Avatar
    Join Date
    Sep 2002
    Location
    Honolulu, Hawai'i
    Shooter
    Large Format
    Posts
    17,284
    Images
    20
    Here's a quick neg scan of the second test exposure--PL100 at EI 100 in FX6a with 90g/l hypo (i.e., the formula as given), 6 min. at 75 deg (which is higher than normal, so that is part of the cause of the excess contrast). The long exposure is probably also partially responsible for the contrast, but on the other hand the light was on the flat side. Tomorrow we should have better weather, so I'll try a test outdoors in normal daylight. There's a little streakiness from the scanner.
    Attached Thumbnails Attached Thumbnails PL100-2.jpg  
    Last edited by David A. Goldfarb; 02-27-2008 at 09:52 AM. Click to view previous post history.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  2. #52
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,022
    Images
    65
    Quote Originally Posted by David Grenet View Post
    This is a bit OT I know, but is this why high sulfite developers don't work for the RA4 reversal process? As they use a chloride emulsion?
    Yes, this is correct, but there is also another reason.

    Sulfite reduces color coupling so if you carry any sulfite excess into the color developer, you can get low dmax. You have to use a very good wash to remove the excess sulfite.

    PE

  3. #53
    David A. Goldfarb's Avatar
    Join Date
    Sep 2002
    Location
    Honolulu, Hawai'i
    Shooter
    Large Format
    Posts
    17,284
    Images
    20
    So does anyone know anything about the keeping qualities, capacity, and replenishability of monobaths? It would be handy, if I could use this as a deep tank developer. Haist talks about sludging as a factor that would work against this.
    Last edited by David A. Goldfarb; 02-26-2008 at 06:50 PM. Click to view previous post history.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  4. #54
    David A. Goldfarb's Avatar
    Join Date
    Sep 2002
    Location
    Honolulu, Hawai'i
    Shooter
    Large Format
    Posts
    17,284
    Images
    20
    Getting closer. Here's one with another 10 g/l of hypo (total 100 g/l). What I've learned is that in the FX6a formula, the quantity of hypo controls the development time, which in retrospect is obvious, but doing it makes it all much more intuitive. The neg is still contrasty, but the shadow detail is good, and the acutance is incredible. I think another 10 g/l of hypo, and I'll be there.

    Don't mind the out of focus foreground. I was shooting my Tech V handheld using the rangefinder instead of the groundglass and didn't notice that I had forgotten to zero the front tilt from the last shot. The streak along the top is a scanner artifact.
    Attached Thumbnails Attached Thumbnails PL100-3.jpg  
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  5. #55
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,270
    Images
    148
    FX6a is definitely a very good staring point, back in the early 60's when Crawley published FX6 (Jan 1961) he mentioned that the Hydroquinone could be increased to increase contrast, it can also be decreased slightly. Crawley gives the capacity etc.

    Ian

  6. #56
    David A. Goldfarb's Avatar
    Join Date
    Sep 2002
    Location
    Honolulu, Hawai'i
    Shooter
    Large Format
    Posts
    17,284
    Images
    20
    Thanks. I figured it would be convenient to be able to keep a batch mixed and adjust the hypo before development, but if that doesn't produce the desired result, I'll mix up a new batch with less hydroquinone.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  7. #57
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,270
    Images
    148
    David, just came across this in my notes, I was looking for something completely different:

    King's All-in-One


    Metol 1.0g
    Sodium Sulphite 40.0g
    Hydroquinone 5.0g
    Sodium Carbonate 30.0g
    Potassium Bromide 2.0g
    Potassium Iodide 2.0g
    Sodium Thiosulphate 13.0g
    Water to 1 litre

    Monobath.pH should be 8.5; ratio of KI to hypo is critical;
    From a 1946 1946 (U.S.P. 2,397,006)

    Never tried it, times should be similar to FX-6a

    Ian

  8. #58
    David A. Goldfarb's Avatar
    Join Date
    Sep 2002
    Location
    Honolulu, Hawai'i
    Shooter
    Large Format
    Posts
    17,284
    Images
    20
    Thanks. I'll have to order some KI and try it some point (probably not for a few months, because we're moving again soon, and I'm trying not to accumulate too much stuff in the darkroom). It looks less expensive than FX-6a, if the capacity is comparable.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  9. #59
    David A. Goldfarb's Avatar
    Join Date
    Sep 2002
    Location
    Honolulu, Hawai'i
    Shooter
    Large Format
    Posts
    17,284
    Images
    20
    Today's discovery--too much hypo in FX-6a not only reduces contrast but also increases base fog. I think I'm settling on 105g/l for Efke/Adox 100.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  10. #60
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,270
    Images
    148
    David, this was the problem I had when designing a monobath for B&W prints, I'll try and find my notes, they may be around somewhere when I clear out my house next month. From memory I think we added a small amount of Potassium Bromide to cure the problem. The fog is dichroic fog.

    Ian



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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