Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,955   Posts: 1,586,013   Online: 668
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 37
  1. #11
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,440
    Images
    148
    Dan's mention of Edmund Industries is also interesting, they have a UK facility just across the North Sea from you Ole in the old Viking capital York :-)

    http://www.edmundoptics.com

  2. #12

    Join Date
    Feb 2004
    Location
    Lobsta
    Shooter
    Multi Format
    Posts
    566
    You would no doubt find the three-volume series Amateur Telescope Making very interesting. Originally published by Scientific American quite some time ago, it's probably out of print, but perhaps has been reprinted or can be found in a good library. While most of it pertains to mirrors and other trappings of amateur astronomy, there are some chapters dealing with lenses. My books are packed away right now, so I can't give you a specific reference, but I believe volume 3 has a chapter on making a triplet of the Cooke type.

    It's one thing to make a single surface as in a telescope mirror. A simple lens is a bit more work since the two surfaces must share the same optical axis. A multiple element lens is something else altogether. Did you plan on leaving any time for photography?
    My Verito page

    Anyone can appreciate a fine print. But it takes a real photographer to appreciate a fine negative.

  3. #13
    Rock Poper's Avatar
    Join Date
    May 2005
    Shooter
    Medium Format
    Posts
    103
    Quote Originally Posted by Terence
    I keep thinking someone should be able to make a hypergon-clone at a reasonable cost. It's only two elements. Surely there's a suitable optical plastic that could be easily molded.
    thats exactly what I was thinking! (re. the hypergon) -
    this lens particularly excited me as it had an almost similar system i was thinking of for a centre ND filter - I was thinking a rotating disk with slots in it - rotating around an axis in the centre of the lens for centre ND falloff correction or off axis for general ND - if you made a big one and placed it near the focal plane - the slots would be big enough to make adjustable -

    Of course tho like all good and bad ideas its prob been done 80 years ago or something -

    Anyways, I want to make a 8x10 - the lens, shutter and holder systems were the ones I thought I would have trouble with, but upon purchasing a holder and looking a few systems, this is easy to make -

    shutters not sure yet, need to pull a few apart and get my head around them (lens cap, long expsosure in the meantime) -

    but wouldn't be great to have made a full 8x10 from scratch - including the lens (grin)

    Once exams are over here (I'm an architecture drop out now engineering student soon to be a arch student (again) engineering drop out) I'm going to put my nose to the grindstone and do it! (the extra hard way)

    cheers,
    rock


    (prob have some more questions once I get going - thanks for the replies!)

  4. #14
    Rock Poper's Avatar
    Join Date
    May 2005
    Shooter
    Medium Format
    Posts
    103
    Quote Originally Posted by wfwhitaker
    Did you plan on leaving any time for photography?
    I guess I am a gear head yes - I do take photos occasionally - as i cant access the gallery yet - I'm going to go and try uploading here

    excuse the bad scans ...
    Attached Thumbnails Attached Thumbnails no-acrosgrey.jpg   up.jpg  

  5. #15
    Murray@uptowngallery's Avatar
    Join Date
    Sep 2003
    Location
    Holland, MI
    Shooter
    Pinhole
    Posts
    1,028
    Go to google, click on groups, search or otherwise
    http://groups-beta.google.com/group/...03ef321eaee53c

    If that link is garbage (doesn't look too alive when pasted), go to
    http://groups-beta.google.com/group/...e-format?hl=en
    And search for
    Metrogon cell spacing revisited HELP

    Brian Caldwell responded. He wrote one of the major optics design programs AND made his own 11x14 Topogon (predecessor of the Metrogon, but follower of Hypergon). He explains why it can be done with relatively cheap variety of optical blanks, discusses some problems he had, but he's no amateur...he does seem to think it was not a big deal. He didn't say how long it took, or what his perspective for inexpensive means (compared to paying someone to do it?)

    I think the achromatizing on that design (oops, I'm diverging to Metrogon again) was accomplished thru the degree of symmetry), and other aberrations corrected thru symmetry and aperture reduction (you don't see smaller f/# than 6.3 to my knowledge on Metrogons. I don't know about Topo- or Hyper- types)

    I can link you to the patents on Metrogon Topogon and an English variant that might not have been commercially popularized.

    Murray
    Murray
    Murray

  6. #16
    Murray@uptowngallery's Avatar
    Join Date
    Sep 2003
    Location
    Holland, MI
    Shooter
    Pinhole
    Posts
    1,028
    Well, the first link I gave looks truncated, but it works.

    M
    Murray

  7. #17
    Rock Poper's Avatar
    Join Date
    May 2005
    Shooter
    Medium Format
    Posts
    103
    great - thanks for that Murray - I'm playing with other recent finds (bolex cine camera) but still have a mind to grind sooner rather than later ...

    it is tho a bit of a long-term project ...

  8. #18
    Neanderman's Avatar
    Join Date
    Mar 2004
    Location
    Ohio River Valley
    Shooter
    Large Format
    Posts
    575
    Get the latest version of Oslo -- it now allows up to 10 surfaces. I've been inputing data for some of the classic lenses (triplet, Tessar, Dagor, etc) from their patent descriptions. It is a great way to learn something about optics.

  9. #19

    Join Date
    Dec 2004
    Shooter
    Large Format
    Posts
    540
    Neanderman:

    "Get the latest version of Oslo "

    Where??

    Thanks.

  10. #20
    Lee L's Avatar
    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    3,244
    Quote Originally Posted by phfitz
    Neanderman:

    "Get the latest version of Oslo "

    Where??

    Thanks.
    http://www.sinopt.com/

    Lee

Page 2 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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