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  1. #21
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    Keith;

    IDK, but my worst experience was when we had phosgene get loose in the lab. OTOH, one day I came into the lab and the door 'banged' just as I arrived. It felt as if the door had pushed back at me. I had trouble opening it and found glass and metal all over the floor keeping the door from moving properly.

    Upon investigation, I found that the hydrogenation bottle had exploded just as I was pushing the door open. It left a dent about 1" deep in the solid metal doors just about chest height. The metal cage and the thick glass bottle were spread in an arc right at the door. Hydrogen escape appeared to be a non-problem.

    Win a few, lose a few.

    PE

  2. #22

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    You mentioned the chemical bigbangs in labs, an echo I found on a patentstudy. It is my private meaning, that some of the intellectual work had to do with following: Company X is angry about company Z and modify their chemistry, that in X-chemistry Z-films get the colour tone of Z-company. Now is the R&D stuff of company Z not stupid and „improve“ their Z-chemistry, that all X-films get the color-tone of X-company. --I cannot proof this, believe it or believe it not. From this patentstudy:

    To increase micro contrast over macro contrast is a splendid idea from GROET und LINDSAY, 14. july 78 US-Patent, in 1999 I mentioned them as one of the few modern ideas in my speech „100 Jahre Kontrastausgleichsverfahren“ 100 years procedures for contrast reducing, you can find on my site, only in german, together with a lot of rare datas
    http://www.gigabitfilm.de/html/deuts...?Layout=normal

    The 25K-ISO Film, light/photons distribution at that intensity are very grainy, clumpsy. Could the sensitivity be more stable against cosmos-radiation for commercial trade with a ultrahigh LIRF, starting at 1/10 sec with 1 stop loss, I am not sure. The other questions has to do with that – hypern (I had posted some experience in german aphog.de) and to switch on speed – once described for a Mars-satellite-cartography-project in a german science magazine 30 years ago.

    By monodisperse films, the positive is the perfect quality near the limits of optical laws. The negative is the reduced tolerance, when you develop with full speed, because you enhance the gaussian distribution curve of production quality, using the film with a chemistry, the emulsion was not constructed for. You need more control and you enhance possible problems. In the combination selected films and chemistry problems are solved. When nothing from outside will disturb it, it's quite equal as highend-digital.

    With HDR-chemistry some users will test a lot of all commercial monodispers films, mostly of them in medium (to get an imagination for rollfilm) or large format. It can be, that the versatility in usable films will grew up, it can be, that some films will give no sufficient results, but to look for new qualities is good for photography.

  3. #23
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    And so it goes.
    "Only dead fish follow the stream"

    [APUG Portfolio] [APUG Blog] [Website]

  4. #24
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    I first met Nick Groet in about 1962 at a conference at Cape Canaveral, along with Paul Vittum. I am familiar with his theories as applied to color films. However, the definitive work on these lines was the lengthy paper by Mike Kriss which I have mentioned here on APUG before. It contains the full meaning of micro vs macro contrast and edge effects. This is applied to this day by Kodak.

    As Keith says, "And so it goes".

    PE

  5. #25

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    A remark to 25K-ISO films. In ultra speed the developing reactions are more efficient or quicker as usual, mistakes will have enough time to constitute themselves. When you see the mathematical precision of the Mackie-lines by monodispers films, you can compare them - in my eyes - with equidensites (once exist a film by Agfa from RANZ - Agfacontour). When you have to do with errors in mathematical forms, then think in mathematical form to minimize them – the interference. With that the field comes You wrote: „ ... antistatic agents and 2 electron sensitization using osmate salts. There are reduction sensitizers, and direct reversal agents similar to the direct reversal you have described here. Kodak has 20 years worth of research on the shelves at this time which has not been realized and this includes ...“

    I have not a direct reversal process, but in my understanding I can fog the weak exposed parts. When the mechanism is now very stable, why not to enhance the system with more „fogging-power“.

    I can prove following: Over 30 years ago, 6,4K-ISO was (or is?) possible on Tri-X, the semester before me in Cologne, photo engineering, find out around 1970 a method for normal gradation with Rochester-Tri-X, not english Tri-X, with pre-fleshing and after-exposure 4?hours, developed in Tetenal Emofin, each bath 30 min at 30 C. Little more grainier than normal with acceptable fog. Once as a student I „safed“ 2 stops underexposed important portraits on TriX with Emofin, each bath 30 minutes, but no pre- or after exposure. I was since 1985 never interested in normal films, but now it could be interesting for to compare past with new, to controll Tri-X how much speed he has. Once I made a simple test for that with my Typ IV chemistry, but the normal resolution of mix-emulsion films was going down, the gaussian sensitifity-distribution was too big enhanced in this speed-enhancement (that's the reason I prefer monodispers). I need only to add some sulfit and depending on grain-size some amounts of Kbr. The positive effect of extrem exposure latitude stays, grain is bigger (perhaps is this something for ULF-users, they need speed).

  6. #26
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    The 24,000 ISO film is normal 400 speed film with 2 addenda. It yields a positive image with the grain and sharpness of the 400 speed parent emulsion. This speed jump takes place with any emulsion, but the final speed is based on the original emulsion.

    Direct positives can be made with converted emulsions and the use of a nucleating agent to give quite high speed, but grainy, images. However, due to internal fog, any silver halide solvent will cause fog, and any overexposure will cause re-reversal. Many commercial products used these. They ultimately vanished due to various problems.

    Normal films developed in the presence of a catalytic agent and color forming materials will experience a huge speed gain with normal grain and sharpness but will have an increase in contrast to some extent, depending on silver level. Usable latitude will decrease and move towards the toe.

    There are many many such processes and tricks in formulation to change films in speed. If they are too hard to process or too hard to manufacture, or the market is too small, they vanish or sometimes, never even come to fruition.

    PE

  7. #27

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    Quote Originally Posted by rmolson View Post
    Fallout fogging paper
    In the mid 60’s I was working in a photofinishing plant in Canton Ohio.
    Probably 1962 or sooner. The last US above ground test was in 1962 with the Limited Test Ban Treaty of 1963 ending that.

  8. #28

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    You can construct only that, you have understand. I remember very well the lesson, Mr J. W. Mitchell hold in Cologne 1986 about developing AgHal in a gelatine matrix and the disturbing in the moment of beginning. The other is the correct coating of an emulsion. Old greecs would say – Scylla and Charybdis.

    From the 6 stops speed, you described, 2 stops (or 2 1/2?) I had made with my efforts, that means, the contrast effect, you described, would be probably not so high (or not) in a fog incorporating developer.

    Your reflections about the different trials to get the full speed will animate me, to look further. I have now noticed, that in my concept of a fog incorporating developer could be a possible potential for „mounting/generate“ the „catalyst/level“ for real speed. I would carry this responsibility for that, in the limits of an independent one-man-show as I act until now.

  9. #29

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    The first simple test, shipping between Scylla and Charybdis, looks interesting, 2/3 stop more on this GTP (chemistry HDR Version I +testad1, 1+10, 28 C, 4 Min), latitude and anything else stays correct, no Mackies, only with one classic substance from this class, but huge.

    In my archiv I remember an article long ago in a newspaper for engineers (VDI-Nachrichten?) about this 25K-ISO film, and a news from the Paris salon for photo and cinema in around 1980?, where a (US-?) Company KEM presented additives for E6, C41 and bw, every additiv enhancing speed around 2-3 stops (from my memory, with no guarantee). I have the feeling, to re-invent parts of this new. Why it was forgotten??

  10. #30
    AgX
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    PE, Gigabitfilm,

    Both of you unfolded roadmaps to 25k ASA. However both of you were so negligent not hand us the thread of Ariadne to find our way in that labyrinthic roadsystem of potions and nuclei.

    By the way, my roadmap, or rather sketch, to 25k is the Solubilization by Incipient Development. (Which is a high-efficiency variant on the classical Diffusion Transfer Reversal, however with some addenda to encapsule the halides to control solubility. Well, some potion…)


    Off topic:
    Gigabitfilm, you wrote “once existed a film by Agfa from RANZ – Agfacontour”.
    To my understanding this film was created by Edith Weyde, though I only found the Ranz et.al. patent. Anyway, a concept of intellectual beauty…

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