Making zone plates with a printer

Discussion in 'Pinhole Photography' started by PhotoPete, Mar 10, 2006.

  1. PhotoPete

    PhotoPete Member

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    Does anyone have experience printing zone plates, pinholes or megapinholes with a printer?

    Did you use a laser or inkjet? What was the DPI of the printer? What kind of material did you print on?

    Thanks for the help.
     
  2. blaze-on

    blaze-on Member

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  3. PhotoPete

    PhotoPete Member

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  4. Ole

    Ole Moderator Staff Member Moderator

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    Print one with whatever printer you have, at whatever resolution your printer gives. Print it on something transparent, if you have that. If not you can print it on paper, then trace it on film using a pen.

    It's a simple interference pattern, designed for one single wave length at one single focal length: It takes a lot before the picture gets visibly softer than it already is!
     
  5. Jim Jones

    Jim Jones Subscriber

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    I downloaded a zone plate from www.whizkidtech.redprince.net/zoneplate for a 20 inch focal length and printed a transparancy of it on an old 600 dpi HP Laserjet, and the results was so awful that I'm not going to mount and photograph with it. A high resolution zone plate from that site could be printed as a large image on paper. That could be scaled down by copying onto litho film or another high contrast film such as Tech Pan developed for maximum contrast.

    A 5000mm zone plate for solar or lunar photography downloaded and printed on the same printer looked almost good enough to try. Exposures for the full moon might barely be practical. If I put this much effort into lunar zone plate photography, I'll download a high resolution zone plate and scale it down onto high contrast film.
     
  6. Ole

    Ole Moderator Staff Member Moderator

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    Get the Pinhole Designer from www.pinhole.cz - calculates pinholes and zone plates, output to pdf.
     
  7. Jim Jones

    Jim Jones Subscriber

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    That's a very nice calculator. However, for optimum on-axis resolution I suggest a user constant of 1.6 instead of the two provided constants. Those two constants might be better for the wider coverage we often want from pinholes.
     
  8. PhotoPete

    PhotoPete Member

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    My concern has been getting the blacks to print dark enough to be truly opaque- I haven't been able to do that with either my HP or Canon inkjets. I will try a laser printer.
     
  9. htmlguru4242

    htmlguru4242 Member

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    I'd say that getting these somehow onto high-contrast film (lith film, copy film, what have you) would probably work better. That'll tend to give better blacks, clear lights and allow for easier & higher resolution zone-plates.
     
  10. PhotoPete

    PhotoPete Member

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    I think you're right about the HC film. My early tests have all come out uniformly gray- I think the inkjet blacks are just not sufficiently opaque. I was hoping to avoid having to buy lith film and developer for this effort, but I may have to go that route.
     
  11. Jim Jones

    Jim Jones Subscriber

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    Lith film is cheap enough, and full development in print developer might suffice, especially when copying a very high contrast original.