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  1. #11
    holmburgers's Avatar
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    Ahh! Greg, of course, you're absolutely right. I'm not sure what I was thinking regarding the LPI (actually I do know what I was thinking, but I'm embarassed to admit it!)

    The Ronchi Ruling is perfect for sure... check please.

    What about one of those "ink-squirting desktop enlargers", are they capapble of that? I'll do some checking
    If you are the big tree, we are the small axe

  2. #12

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    Quote Originally Posted by holmburgers View Post
    The Ronchi Ruling is perfect for sure... check please.

    What about one of those "ink-squirting desktop enlargers", are they capapble of that? I'll do some checking
    I don't think so...I've played around with it a bit about a year ago, and for line-screens like this, the best I was able to get was about 540 dpi (270 lp/in). I've heard of a few new tricks since then that I'd like to try, but I don't have that printer anymore.

    --Greg

  3. #13
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    How much do you think the image-setter service would run? That might be the best option.

    Another thing I've wondered about is the mathematical relationship between the gratings (2000, 2400, 2750) and how those relate to the primary color wavelengths. It might be painfully obvious, but I can't see it.

    I think there's a lot of creative potential for this kind of "print". Imagine having a large image made in this way, and mounted as a window high in a room with vaulted ceilings, for instance. By moving about the room, the image would shift through a menagerie of colors and only at one specific location would the proper colors pop into being. I think that could be really fantastic.
    If you are the big tree, we are the small axe

  4. #14
    holmburgers's Avatar
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    Wow, I just came across this -> http://prola.aps.org/abstract/PRI/v22/i6/p339_1 - Improvements in the proces, and from 6 years later, by the man, F.E. Ives's son, Herbert. (he was intergral in the development of color television)

    This appears to be the original article in Science -> http://www.sciencemag.org/content/9/234/859.extract
    Last edited by holmburgers; 06-10-2011 at 12:51 PM. Click to view previous post history.
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  5. #15

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    Quote Originally Posted by holmburgers View Post
    Another thing I've wondered about is the mathematical relationship between the gratings (2000, 2400, 2750) and how those relate to the primary color wavelengths. It might be painfully obvious, but I can't see it.
    Well, if you crunch the numbers, you get the following:

    2000 lp/in = 78.74 lp/mm = 6.35 um (micron) line or space
    2400 lp/in = 94.48 lp/mm = 5.29 um line or space
    2750 lp/in = 108.3 lp/mm = 4.61 um line or space

    Looking at those numbers, they are about 10x the wavelength of what might be considered red, green and blue light, respectively (though the blue seems a little long to me). I would guess it has something to do with the power of the viewing lens and the angular offset that is desired/needed. I would further guess that other combinations of viewing angles and lenses might benefit from different line screens.

    I'm very definitely not an optics person, so maybe someone else can explain further, 'cause I'm at my limits, here.

    BTW--First link in post #14 requires membership.

    --Greg

  6. #16
    holmburgers's Avatar
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    Ah, thanks for doing those numbers Greg. That makes sense, but I couldn't figure out how to get there. The blue does seem a tad long, but must be ok -> http://en.wikipedia.org/wiki/File:Li...e_spectrum.svg

    Sorry, yeah I don't have a subscription to that either, but I found it on Google books via that citation -> http://books.google.com/books?id=Trc...page&q&f=false (type in page 339)

    I actually haven't read it yet, so I'm not sure what the improvement is. Unfortunately, the google books scan has cut off the bottom of each page, so I don't know how coherent it's going to be.
    If you are the big tree, we are the small axe

  7. #17

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    Quote Originally Posted by holmburgers View Post
    How much do you think the image-setter service would run? That might be the best option.
    I just realized I left you hanging on this...

    Assuming you want to make 4x5" images...

    2750 lp/in (@ 4x5") --> ?? @ 600 lp/in (imagesetter film)
    2750/600 = 4.583x reduction

    4*4.583 = 18.333"
    5*4.583 = 22.9"

    Looking at the on-line price list of a service bureau in my area, they charge:

    19 x 25 $48.75
    20 x 26 $54.50
    22 x 28 $63.25

    Hope that helps.

    --Greg

  8. #18
    holmburgers's Avatar
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    Hey Greg,

    That fact that you don't treat a question like that as rhetorical is a testimony to your character.

    OK, I think I fully understand what you're proposing now. You'd get just one of these films, and use it as a master to make smaller line rulings on a high-contrast film.

    A short aside; so I found a biography of Herbert Ives and the above mentioned "Improvements in Diffraction Color Photography" [sic] was one of his graduate papers while at Cornell, IIRC. Same with a similar paper on Lippmann photography by him. I love imagining the period when stuff like this was cutting edge; being studied at institutes of higher learning. I guess that Professor Wood himself was the authority on color at the time, according to the biography I read.
    If you are the big tree, we are the small axe

  9. #19

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    Quote Originally Posted by holmburgers View Post
    OK, I think I fully understand what you're proposing now. You'd get just one of these films, and use it as a master to make smaller line rulings on a high-contrast film.
    Right...exactly...a single master, generated at the native resolution of the imagesetter (600 lp/in works well for 2400 and 3600 dpi imagesetters). 3 different reproduction scales to get your rulings for imaging. BTW--Some can also image directly onto RC paper...it should support that resolution. And you have a reflective master to work with, instead of having to rig up a big backlight.

    If you end up going down this road, make sure the service bureau really understands what you're looking for in terms of output. It's probably way outside their realm of experience, unless they've done other weird stuff for alt-process people before.

    --Greg
    Last edited by gmikol; 06-14-2011 at 03:45 PM. Click to view previous post history.

  10. #20
    holmburgers's Avatar
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    I like the idea of getting it on RC paper. I was already trying to figure out how the heck I'd back-light that...

    Bob Carnie might be someone to consult on this issue.

    Even though I can't possibly say that I'll be doing this tomorrow, or next week, or even this year!, it's on my list of things to do for sure. I do think that you've proposed the best route to do it.
    If you are the big tree, we are the small axe

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