Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,951   Posts: 1,585,988   Online: 847
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 38
  1. #11
    PDH
    PDH is offline

    Join Date
    Nov 2005
    Shooter
    Multi Format
    Posts
    528
    While in college in the 60s part of our course work involved mixing chemistry and we tired several monbath developers, the idea was to have a very fast acting monbath that with a short wash and forced air dry could be ready for the "special editions" for newpapers in short order. I dont recall which monbaths we worked on, but all had high contrast and very grainey. I also used the old black and white ide film that Poloraid sold in the 80's which I think was a monbath. I liked the Polorid process.

  2. #12
    Worker 11811's Avatar
    Join Date
    Jan 2010
    Location
    Pennsylvania, USA
    Shooter
    Multi Format
    Posts
    1,628
    Quote Originally Posted by holmburgers View Post
    It's all supposing until given the old college try. I'm glad Andy C. is going to take a stab at it.
    I'm not saying it won't work or, at least, didn't work for a particular application at a particular time. I am simply saying that the author seems to be reporting what others have told him without ever having done it himself.

    It would be like me saying, "There's a guy who can develop Kodachrome in his home lab."
    We all know it has been done. We know how it was done. There are a few who can even do it themselves but I've never done it myself.

    The article is logically the same as me telling you how to develop Kodachrome in your home lab without ever having done it myself.

    If I told you how it was done (and recounted the process correctly) would I be wrong in reporting that? No.
    If I gave commentary and made suppositions on how one might do it in his own darkroom, would I be wrong? No, with caveats. That caveat would be that I didn't relate opinion as if it was fact.

    The difference is that, at the time that article was written, one could give opinions and the reader would probably understand that. After all, he was an expert in the field. Other readers would likely understand that. However, in this day and age, we don't write with the same style and it's easy to misinterpret that style to mean that he is telling us facts.

    Not saying the guy is wrong. Not saying the article is bad.
    He is probably right. The article is probably very good for the time it was written.
    I'm simply saying that we need to read critically and account for things like that.
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

  3. #13
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,423
    Images
    2
    Yes Randy, I'm sure you're right about this; I didn't mean to sound like I was countering what you said.

    What I was hoping to say, ultimately, is that someone's gotta test it; we need to revisit it in present day and make our conclusions based off that, because like you say Haist probably didn't do it himself and is just kind of passing it on "for what it's worth".

  4. #14
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,439
    Images
    148
    The monobath formula itself isn't exceptional it's close enough to some of Haist's own and Crawley's FX-6a, it was published in 1954 and is MQ based, Phenidone was only just becoming commercially available, and Haist, Crawley & others used Phenidone in the late 50's/early 60's, PQ monobaths are less afffected by bromides than MQ.

    It's going to develop faster than FX-6a and Haist's own quite similar monobaths, the rate of fixing is depenant on the percentage of Sodium Thiosulphate which is usually somewhere between 7-12%.

    The question that needs to be asked is why is this Monobath being used to reversal process film, what was the application, we know now that Haist writes that there is a weaker negative imge alongside the strong positive image.

    From a practical point of view it'd be useless for producing reversal B&W slides where you need clean highlights etc, but it may have been useful for an industrial/scientific applied use of photography to process a recording material.

    I used similar monobaths with a film type orthochromatic emulsion and also normal photographic papers and the development is quite fast, you need the longer times recommended for FX-6a to ensure fixing is complete.

    So the question to Mark is does Haist say what application Howell was using this monobath as a reversal developer with ?

    Ian

  5. #15
    Nicholas Lindan's Avatar
    Join Date
    Sep 2006
    Location
    Cleveland, Ohio USA
    Shooter
    Multi Format
    Posts
    2,381
    Images
    4
    I just tried it and this has to be the crappiest developer on record [do anything to get out of writing a final report].

    Exposed Arista 100 EDU at 400, developed it as per instructions for 4 minutes.

    The result is an underexposed, underdeveloped negative with blown highlights. Or, I suppose you could look at it as an overexposed, overdeveloped negative with no shadow detail - shadows starting at Zone IX or so.

    Not even the faintest trace of any reversal of anything.

    There may exist a film/developer-tweak/time&temperature combination that works, but the results I had are so far out of the ballpark that it is hard for me to imagine this ever going anywhere.

    YMMV and all that.

    In Haist's defense he did attribute it to a FOAF [to put it in modern English].
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  6. #16
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,439
    Images
    148
    Sometims Monobaths were used for very strange applications, it would appear that Hutson K. Howell was a highly respected photo chemist.

    Without knowing what the true application of this Reversal monobath was we could go round and round in circles.

    Ian

  7. #17
    Oxleyroad's Avatar
    Join Date
    Jun 2007
    Location
    Hawthorn Oz, then MI USA from March 14, 2015!
    Shooter
    Multi Format
    Posts
    816
    Blog Entries
    1
    Images
    7
    Nicholas has beaten me to it by the looks of it. I waited until the sun came up this morning to shoot a bracketed roll which will be souped after I take the kids to swimming classes.

    Not expecting anything spectacular, but glad I have waited to read Ian's suggestions.

    Will try to post examples by the end of the day.
    Cheers - Andy C
    ---------------------

    16mm Cine, 35mm, 120, 5x4 & 7x5.

  8. #18
    Bill Burk's Avatar
    Join Date
    Feb 2010
    Shooter
    4x5 Format
    Posts
    3,593
    Images
    46
    Thanks Nicholas for doing some real tests!

    But the underlying question, "Can reversal processes improve film speed?," might not have been given a whole lot of thought back in the day when it was kind of hard to print from positives.

    You have to nail the exposure, because instead of all that latitude now you are working with slides. But think of all the threads that teach us how to do that.

    I used to shoot Panatomic-X at 80 for reversal and its rated speed is 32 for regular process.

  9. #19
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,423
    Images
    2
    There are situations when you might need a positive to print from; where any kind of excess fog or density (which would render a poor slide) could easily be printed through.

    Just a thought..
    If you are the big tree, we are the small axe

  10. #20
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,561
    Images
    65
    Paul Gilman showed that ISO 400 emulsions could be boosted to ISO 25,000 by appropriate reversal processing using heat. Grant found the same thing with negative heat processes.

    PE

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