P 6x7 for astrophotography

Discussion in 'Medium Format' started by greg_mueller, Aug 29, 1998.

  1. Is any one out there using the Pentax 6x7 for astrophotography?
    The demand on the lenses, exceeds normal demands and I need help in selecting telephotos that will perform. Thanks
  2. Greg: I've only used it for comets and a few lunar eclipses with so so results except for Hale-Bopp. I used my 300mm at f/4 for 30 seconds using Kodak PMZ 1000 color print, undriven, shot at 7000'elevation. I have yet to use my 600mm for this purpose but will when we get our next comet. The 600 has a 5.8 inch front objective, so it lets in a lot of light. It can be shot at f/4 but don't have any of the subject near the edge of the field; it's soft in that area wide open. SR
  3. It is my understanding that Pentex will modify it's camera for astrop use by allowing very long exposures w/o drain on battery. Call them.
  4. Hi Greg,


    I use my P67 for astrophotography and I4m very satisfied with the
    results. The 2,4/105 can be used full open, I4m testing the 4,0/200 in
    the next time. For real telephoto I use an special adaptor for my
    astrophysics refraktor. I have no good results yet, because of the
    poor quality of my mount.
    Ask me, if you have further questions


  5. The Pentax 67 is used by a good number of astrophotographers. In
    fact, many of the outfits specializing in astrophotography equipment
    have various accessories for the P67 – and in some cases the P67 is
    the only MF system they support. The 400mm lens is often used –and
    highly regarded- but as is the 300mm, 200mm, and even the standard
    105mm. The adapted P67 camera is owned and routinely used by various
    astronomy pads & research centers (Australia, U.S., Canada, etc.).
    If you are interested in basic “FAQ” sorts of things for
    astrophotograpghy, Hutech offers such a link:
    http://www.sciencecenter.net/hutech/techdocs.htm . As others have
    noted here and elsewhere, if you are interested in doing much of this
    you will probably want to have you camera modified; the battery-drain
    modification runs from $80-300, depending on where it is done, the
    turn-around time requested, how far the camera has to be shipped,
    etc. For a run-down on what might be the most that can be done, and
    the benefits of it, this site has a nice synopsis:
    http://www.company7.com/library/ptxshtr.html . If you are curious
    what a fairly elaborate setup -complete with astrograph, Telescope,
    etc.- looks like (note: setups larger than this usually look as much
    like an anti-aircraft weapon as a photography base), this site has
    fairly descriptive pictures, and some commentary:
    http://www.airdigital.com/astro_eqpt.html . You will discover that,
    basically, if you do anything more than having the anti-battery-drain
    upgrade, you will be looking at an investment that may be more
    significant than adding another lens to your existing setup. That
    said, there are several accessories on the market. For instance,
    Stellar International in Texas has dual-bayonet mounts and “Stiletto”
    assemblies (focusers) for the P67; see http://www.stellar-
    international.com/mformat.html . Telescopic mounts and other
    accessories for the P67 are offered by Williams Optics Team in
    Washington; see http://www.williamoptics.com . Hutech, the people
    mentioned above, offer a camera-to-telescope interface for the P67;
    see: http://sciencecenter.net/hutech/ptown/medium.htm . An even more
    expensive option is an actual astrocamera, and there are makers
    offering this in the P67 mount; for a brief site, with a picture of a
    functioning camera, see: http://www.koheisha.co.jp/e-
    mspenta6701.html . Many sites feature a few pictures taken with the
    P67. Last but not least, photographers/webmasters often acknowledge
    the focusing problems they have gone through before settling in on
    a “method” that works for them (one such site hinting at this, and
    hinting more info will follow is: http://astrophoto.home.att.net ).
    These comments, and those found in some of the links to the above-
    mentioned website, are quite valuable.

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