Mounting a Tamron 500mm Adaptall-2 lens on a Pentax K200D

Discussion in 'Pentax' started by Peter, Jan 17, 2009.

  1. Peter

    Peter Guest

    I wonder if there is a direct adapter.

    There are plenty of AD2 to M42 thread mount adapters, but is there an
    AD2 to Pentax-DSLR (whatever it is called) adaptor?

    I've done google searches but cannot find anything.

    The 500mm is a catadioptric lens which is fixed at F8 and has a focus
    ring only. The camera would be used in manual mode.

    Any pointers would be much appreciated...
    Peter, Jan 17, 2009
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  2. Peter

    Rob Morley Guest

    AIUI any of the standard Pentax bayonet mounts from the original K
    series onwards will work in full manual with the DSLRs. The earliest
    will work only with stop-down metering, but that's irrelevant to this
    lens anyway.
    Rob Morley, Jan 17, 2009
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  3. Peter

    Bruce Guest

    Yes, there are direct Adaptall adapters available, both Pentax K and
    Pentax KA mounts. The KA mount is a simple, dumb, mechanical mount. The
    KA mount is a little more sophisticated and allows electronic transfer
    of aperture information to the camera body, plus it enables shutter
    priority mode with suitable lenses. However, you have no need of that
    with a fixed aperture catadioptric (mirror) lens, so the K mount will be
    just fine.

    That's a good thing, because Tamron no longer manufactures Adaptall
    mounts and only very few KA adapters were ever made. Also, I have heard
    that they were less reliable than the simple K adapter but have no
    personal experience to back that up.

    Even the K mounts are quite rare, so you might find the quickest way to
    get going is to obtain an Adaptall M42 adapter (as you say, they are
    easy to find) and a Pentax branded M42 to K mount adapter. There are
    several brands of M42 to K mount adapters available.

    However, it is worth getting a genuine Pentax adapter as they can easily
    be removed from the camera's lens mount without any need for a separate
    key, which all other brands need. They keys are easily lost in the dark
    recesses of a gadget back. Removing the Pentax adapter is a trivial
    task, and you can be sure that the register of the lens will be 100%
    Bruce, Jan 17, 2009
  4. Peter

    Rob Morley Guest

    Rob Morley, Jan 17, 2009
  5. Peter

    Bruce Guest

    gadget bag, sorry.
    Bruce, Jan 17, 2009
  6. Peter

    Peter Guest

    Thank you all for the replies.

    I have actually decided to put the lens on Ebay because I have hardly
    used it over the years, and they seem to fetch amazing prices...

    The funny thing is that the replies did not appear in Usenet for some
    hours, but they appeared quickly on some web forum whose content is
    obviously stuffed from Usenet using some automated service :) There is
    a huge # of web forums like that.
    Peter, Jan 18, 2009
  7. Peter

    Paul Giverin Guest

    Probably a problem with your news server (Zen). I just had a look on the
    Zen Internet section of the "thinkbroadband" forums and I found this
    extract from a recent post:-

    "The news server is playing up.
    Postings are still delayed and Zen is running behind google groups."

    Paul Giverin

    British Jet Engine Website:-

    My photos:-
    Paul Giverin, Jan 18, 2009
  8. Peter

    Bruce Guest

    You're welcome.

    Optically, the Tamron is one of the better mirror lenses. That's why it
    will fetch good money. Over the years I have owned two, and hardly ever
    used either of them, so I sold them both.

    I still have an Ohnar 350mm f/5.6 which is exceptionally light and
    compact. The maximum aperture of f/5.6 is much more usable than f/8,
    and it is optically almost as sharp as the Tamron.

    For an inexpensive telephoto lens for occasional use, look at a 300mm or
    400mm fixed focal length glass lens with a maximum aperture of around
    f/4.5. There are some surprisingly sharp optics from Sigma and Paragon,
    and they fetch very little money on eBay. The cheapest have pre-set
    aperture control, but that hardly matters.

    You might even find one in Pentax K mount, although M42 versions are
    very common indeed, and particularly cheap.
    Bruce, Jan 18, 2009
  9. Peter

    Bruce Guest

    Well, I did say:

    Well done, though!
    Bruce, Jan 22, 2009
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