Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,693   Posts: 1,548,967   Online: 817
      
Page 3 of 7 FirstFirst 1234567 LastLast
Results 21 to 30 of 64
  1. #21
    Dean Williams's Avatar
    Join Date
    Jan 2004
    Location
    Northern Idaho
    Shooter
    Multi Format
    Posts
    212
    Images
    5
    The thing is, if it "could" be done, it still "can" be done. How much and how fast is the thing. When this little hobby started out, everyone was an amateur. As far as shutters go, any watch maker worth his salt can make one. Even with as meager a machinists' background as mine, a person could make one. Could probably pump out as many as 6-8 per year. To keep it simple enough to make easily, it would only have a top speed of about 1/150 sec, but that's probably more than you'd need if you were making your own emulsion.
    [COLOR=Sienna][FONT=Arial]Some days are diamonds. Some days a tree crashes through your roof.[/FONT][/COLOR]

  2. #22
    Donald Qualls's Avatar
    Join Date
    Jan 2005
    Location
    North Carolina, USA (transplanted from Seattle)
    Shooter
    Multi Format
    Posts
    1,845
    I'm with Ole on shutters -- simple mechanical devices like these, that don't run continuously, can reasonably be expected to last centuries if cleaned and adjusted periodically. I have three from the late 1920s that are within 1/2 stop at all speeds from 1 to 1/200, and I expect them to be still usable after I'm long gone, unless they're destroyed by environmental insults. FWIW, I also own a mechanical clock from the same era, one that wasn't expensive when new, which does run continuously -- and which I've recently managed to adjust to the point of gaining or losing less than a minute a month, the same accuracy that used to be advertised for quartz watches. Same for glass -- American Civil War era lenses can still make fine images, 140 years later, and there's no reason to believe non-exotic glasses will deteriorate in normal storage and use for millennia; they'll be destroyed by rough cleaning or physically broken first.

    I have an electronic copy of a 1920s book on making emulsions, which includes the (1920s style) chemical names of the sensitizing dyes and very detailed process information. I can't see this as being beyond the ability of the kind of people who used to perform the experiments that got written up in Scientific American's, "Amateur Scientist" features; it's certainly simpler in many ways to make a gelatin-halide emulsion and coat it on glass, acetate, or polyester than it is to, say, extract and amplify DNA from plant cells (as I recall being done in one such article) or build a basement fusion reactor (as has also been done -- no, the rate of fusion is well below break-even, but they're working on it). The modern ISO of the emulsions covered in the book I have would range up to 100, possibly even 400 with the right ripening process (though it would be as grainy as old Royal X or 4275 Recording Film -- might not matter, if it were coated on 8x10 plates).

    What this won't be is cheap. Now, someone like me (with very limited disposable income) can pursue photography fairly seriously, as long as he's patient and mechanically astute, without spending a bunch of money (I probably spent less than $1000 in 2004 including all equipment purchases, film, and processing/chemistry). Once large volume manufacture of film ends, unless we have something akin to Star Trek replicators we'll be forced to spend lots of time and money just to create the medium to record the image. Our hobby will become somewhat akin to fireworks making -- dealing with chemicals that, though reasonably common on an industrial basis, are expensive and hard to get in small quantities, might be hazardous to handle, and will involve enough work for a single use that most won't bother. The difference is, you can still buy fireworks, most places (even if they're illegal) if you're not inclined to make your own. By the time most photographers are making their own materials, you'll only be able to buy them from someone who makes them by hand or in very small volume.

    Look at what Bostick & Sullivan get for carbon printing tissue that's not even presensitized -- and think what that would cost if it incorporated five times as many manufacturing steps, in the dark, and included silver as an ingredient instead of soot. That's what film will cost once it's made in runs of 100 sheets of 8x10.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  3. #23

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Donald - is that 1920's book available online somewhere? And how about the basement nuke reactor, I'd be interested in reading about it too! Do I need a basement as large as the University of Chicago's Stagg Field for that?

  4. #24

    Join Date
    Sep 2002
    Location
    Omaha, Nebraska
    Shooter
    Multi Format
    Posts
    2,512
    Images
    4
    I have a freind who is a physics professor and is working on making a bench top fusion reactor. I don't know all the details but it uses dueterium for the fuel and is contained in a stainless steel pressure vessel that most CNC equiped machine shops can make. It is basically used to demonstrate how fusion takes place. If you do some google searches about fusion reactors you will eventually find several sites dedicated to making such experimental devices.

    Last year I helped him put together a cloud chamber that could be hooked up to a video camera or 35mm for time exposures. Pretty neat.
    "Fundamentally I think we need to rediscover a non-ironic world"
    Robert Adams

  5. #25
    Donald Qualls's Avatar
    Join Date
    Jan 2005
    Location
    North Carolina, USA (transplanted from Seattle)
    Shooter
    Multi Format
    Posts
    1,845
    The link where I got the book has been gone for some time -- as I recall, it was the U. Mich. library, and they had a project going to digitize a bunch of old, out of print books, that was likely scotched by changes in the copyright laws such that they can't be certain a work published in 1925 is in public domain (and on their level, if they're not certain enough for their legal staff to bet their jobs, it's pulled). It's a very large HTML file with accompanying JPG images (charts and drawings, not photographs for the most part); the title is "PHOTOGRAPHIC EMULSIONS: THEIR PREPARATION AND COATING ON GLASS, CELLULOID AND PAPER, EXPERIMENTALLY AND ON THE LARGE SCALE" by either E. E. Wall or E. S. Wall (the scan is bad, shows as E. 3. Wall -- could also be E. G. Wall, I suppose).

    The basement fusion reactors were of the "fusor" design (on which you can find a number of web pages with a Google search) -- electrostatic confinement, deuterium fuel (though their plasma formation and confinement can be demonstrated without the risk of neutron irradiation using plain hydrogen), and in theory the possibility to extract fusion energy as a direct current between the core and the vacuum chamber shell. The biggest one I've heard of, anywhere, was in the range of a 24" vacuum chamber diameter; they're theorized to have a break even at around one meter confinement core diameter (which would be about a 2 m chamber) -- assuming one can make the direct current extraction work, find a way to trap the fusion neutrons (to avoid killing all organisms within a few hundred meters), keep the 3He cleared from the core and inject fresh deuterium, etc. The equipment is on the same order of cost and difficulty to build as an astronomical mirror aluminizing machine, but potentially lethal to operate...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  6. #26

    Join Date
    Jan 2005
    Location
    Moscow, Russia
    Shooter
    Medium Format
    Posts
    768
    Images
    36
    I once coated myself some wet collodion plates for our scientific work - and they worked quite well, being 60x75 centimeters big! Both continuous tone and line plates were made in our lab without much effort, so it's not a problem I got notes about it somewhere in my workbooks, so I can post it here if someone is interested

    Cheers from Moscow,
    Zhenya

  7. #27

    Join Date
    Sep 2002
    Location
    Tijeras, NM
    Shooter
    Medium Format
    Posts
    1,246
    In the old times they just laid a huge sheet of acetate on the table and poured the emulsion on it. Making multiple layer films this way is impossible but a single layer is not too bad. Super xx was the last single layer film, which is what many of us LF people want anyway.

    I dont see any pollutant 'side streams' from this process either.
    EK probably made most of their raw materials and this would explain the pollutants. Somebody doing this in their garage would be buying all their starting materials.
    The dyes used to sensitize the emulsion are well known.

  8. #28
    Dave Wooten's Avatar
    Join Date
    Nov 2004
    Location
    Vegas/mysterious mohave co. az, Big Pine Key Fla.
    Shooter
    ULarge Format
    Posts
    2,715
    Images
    20
    Question to the mentioned topic if Kodak ceased all production and kept their formulas "secret"

    1. Are the formulas protected by patent?

    2. Isn't one of the requirements for patent protection that the patent be used? That is you can not be awarded a patent and just sit on it......

    3. It shouldn't be that difficult for formulas to be duplicated?

    4. Would it be cost effective and would other companies step up to the plate even if the most popular formulas were available....

  9. #29

    Join Date
    Sep 2002
    Location
    Tijeras, NM
    Shooter
    Medium Format
    Posts
    1,246
    Patents are only good for 17 years.

  10. #30

    Join Date
    Sep 2002
    Shooter
    Large Format
    Posts
    4,530
    The dyes used to sensitize the emulsion are well known
    Do you know where I can find this information? If you have checked it out, do you know if they are terribly expensive?

Page 3 of 7 FirstFirst 1234567 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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