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Re: How to create a high resolution image of a hammer

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  • Erik Krause
    ... Just for the records: There are several combinations of standard lenses and standard achromatic close-up lenses that make up a (near) telecentric combo:
    Message 1 of 15 , Jan 26, 2013
      Am 25.01.2013 11:43, schrieb johntunley:
      > Thanks for the link to the telecentric lens articles which are worth
      > a more detailed look, unfortunately timescales prevent that just
      > now.

      Just for the records: There are several combinations of standard lenses
      and standard achromatic close-up lenses that make up a (near)
      telecentric combo: f.e the Canon EF 100mm 1:2.8 IS USM macro lens
      together with a 5dpt close-up lens as well as the EF 100-400 1:4.5-5.6
      IS USM (at 400mm) with a 2dpt close-up lens. Both must be used at near
      focus.

      I've discovered both accidentally when playing around with close-up
      lenses I happen to own. For the EF 100mm I used a step down ring
      (67->58mm) which doesn't cause vignetting and allows to use my
      collection of 58mm filters. It doesn't work with the older Canon 100mm
      macro lenses though...

      The 2dpt close-up lens is recycled from a 500mm f/8 Beroflex telephoto
      lens (where the back lens group was blinded by bad lens fungus). I use
      it with a step down ring (77->72mm). I mention this because the distance
      between close-up lens and base lens is critical.

      In fact any combination of close-up lens and base lens should work if
      some kind of extension tube is used which places the focal point of the
      close-up lens in the entrance pupil of the base lens, which effectively
      projects the entrance pupil and hence the no-parallax-point at infinity
      behind the camera.

      --
      Erik Krause
      http://www.erik-krause.de
    • Gerhard Killesreiter
      ... Hash: SHA1 ... Is there a tutorial how I can determine which add-on lens I need to buy for a given macro lens? I have a Sigma 105mm macro. Cheers, Gerhard
      Message 2 of 15 , Jan 26, 2013
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        > In fact any combination of close-up lens and base lens should work
        > if some kind of extension tube is used which places the focal point
        > of the close-up lens in the entrance pupil of the base lens, which
        > effectively projects the entrance pupil and hence the
        > no-parallax-point at infinity behind the camera.


        Is there a tutorial how I can determine which add-on lens I need to
        buy for a given macro lens?

        I have a Sigma 105mm macro.

        Cheers,
        Gerhard


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      • Erik Krause
        ... I don t know of any. However, it s not limited to macro lenses, any lens will do as a base lens. First determine where the no-parallax-point (NPP) of the
        Message 3 of 15 , Jan 26, 2013
          Am 26.01.2013 15:59, schrieb Gerhard Killesreiter:
          >> >In fact any combination of close-up lens and base lens should work
          >> >if some kind of extension tube is used which places the focal point
          >> >of the close-up lens in the entrance pupil of the base lens, which
          >> >effectively projects the entrance pupil and hence the
          >> >no-parallax-point at infinity behind the camera.
          >
          > Is there a tutorial how I can determine which add-on lens I need to
          > buy for a given macro lens?

          I don't know of any. However, it's not limited to macro lenses, any lens
          will do as a base lens. First determine where the no-parallax-point
          (NPP) of the base lens is just as for panorama shooting. Next calculate
          the focal length of the close-up lens, it's 1/dpt in meters. So if it
          has 2 dpt (diopters) the focal length is 50cm. Place the close-up lens
          by it's focal length in front of the NPP of the base lens. In our
          example you should place it 50cm in front of the NPP.
          You can even use an inverted other lens if you don't have a close-up
          lens, like Rik did in his setup:
          http://www.photomacrography.net/forum/viewtopic.php?t=1032
          In this case the correct position must be found by try and error

          Another combo can be found here:
          http://www.photomacrography.net/forum/viewtopic.php?t=18323

          For more one telecentric macro shooting search Rik's page for
          "telecentr": http://janrik.net/RiksLinks.html

          --
          Erik Krause
          http://www.erik-krause.de
        • Lionel
          Companies like JD Edwards, Melles Griot and other have some tutorials that explain exactly what telecentricity is. Based on my research on this topic, your
          Message 4 of 15 , Jan 26, 2013
            Companies like JD Edwards, Melles Griot and other have some tutorials that explain exactly what "telecentricity" is. Based on my research on this topic, your best resource will be the links to photomacrography.net that were posted earlier. As far as I can tell, this is relatively novel ground for photographers in general; Rik Littlefield's articles are the best I've found.

            Regards
            --- In PanoToolsNG@yahoogroups.com, Gerhard Killesreiter wrote:
            >
            > -----BEGIN PGP SIGNED MESSAGE-----
            > Hash: SHA1
            >
            >
            > > In fact any combination of close-up lens and base lens should work
            > > if some kind of extension tube is used which places the focal point
            > > of the close-up lens in the entrance pupil of the base lens, which
            > > effectively projects the entrance pupil and hence the
            > > no-parallax-point at infinity behind the camera.
            >
            >
            > Is there a tutorial how I can determine which add-on lens I need to
            > buy for a given macro lens?
            >
            > I have a Sigma 105mm macro.
            >
            > Cheers,
            > Gerhard
            >
            >
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            > dckAoLwQJo3t5TnCjui8Tu38/rvYlPaH
            > =LlRe
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          • Rick Drew
            I ve also used my desktop scanner. My old model would do legal size scans up to 4800 dpi. I d scan old coins at some phenomenal resolution. From:
            Message 5 of 15 , Jan 26, 2013

              I’ve also used my desktop scanner. My old model would do legal size scans up to 4800 dpi. I’d scan old coins at some phenomenal resolution.

               

              From: PanoToolsNG@yahoogroups.com [mailto:PanoToolsNG@yahoogroups.com] On Behalf Of Lionel
              Sent: 2013-01-26 3:52 PM
              To: PanoToolsNG@yahoogroups.com
              Subject: [PanoToolsNG] Re: How to create a high resolution image of a hammer

               

               


              Companies like JD Edwards, Melles Griot and other have some tutorials that explain exactly what "telecentricity" is. Based on my research on this topic, your best resource will be the links to photomacrography.net that were posted earlier. As far as I can tell, this is relatively novel ground for photographers in general; Rik Littlefield's articles are the best I've found.

              Regards

              --- In PanoToolsNG@yahoogroups.com, Gerhard Killesreiter wrote:
              >
              > -----BEGIN PGP SIGNED MESSAGE-----
              > Hash: SHA1
              >
              >
              > > In fact any combination of close-up lens and base lens should work
              > > if some kind of extension tube is used which places the focal point
              > > of the close-up lens in the entrance pupil of the base lens, which
              > > effectively projects the entrance pupil and hence the
              > > no-parallax-point at infinity behind the camera.
              >
              >
              > Is there a tutorial how I can determine which add-on lens I need to
              > buy for a given macro lens?
              >
              > I have a Sigma 105mm macro.
              >
              > Cheers,
              > Gerhard
              >
              >
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              > Version: GnuPG v1.4.11 (GNU/Linux)
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              > iEYEARECAAYFAlED71AACgkQfg6TFvELooRDnwCglMgd/q3DvALvmapmUsYqVwI8
              > dckAoLwQJo3t5TnCjui8Tu38/rvYlPaH
              > =LlRe
              > -----END PGP SIGNATURE-----
              >

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