Pentax 2X vs. 1.4X test

Discussion in 'Medium Format' started by michael_reichmann|1, Apr 17, 2002.

  1. I have just published a test of the Pentax 67's 2X Extender vs. the 1.4X Extender. The test was done with the Pentax 400mm f/4 ED(IF) lens. What made the test interesting as well as problematic was the expected Pentax 67 problems of shutter vibration, and the need for approriate support when shooting with such very long lens combinations (800mm).

    <p>

    http://www.luminous-landscape.com/p-ext.htm

    <p>

    Michael

    <p>

    The Luminous Landscape
     
  2. Michael, if you hadn't already made your site, you should be forced
    by law to do so.
     
  3. Michael,
    Another EXCELLENT commentary. Thanks once again. You mention in your
    summary that you had used a similar/same combination in Yellowstone in
    the winter. If you don't mind me asking, and I don't mean this to
    sound in any way insulting, or stupid, but do you know how much all
    your usual field gear weighs? Also, and again if you don't mind
    saying so, do you transport it all yourself? Just curious. It sounds
    like it would require at least two fit people to get it to a remote
    location.
     
  4. Michael,
    One question on your test; You are talking on heavy tripods and
    vibrations. To me it looks as if you are using the onepoint
    technique. The lens/camera are only fastened in one point - the
    tripods head. Using long lenses I do always try to get as much
    support as possible. Best support is simply laying the camera
    on
    ground. Landscapes like yours testsite I always try to get support
    from the tipod and an additional point (I love viewpoints with a
    sturdy banister)
     
  5. Carl,

    <p>

    My camera kit depends on the type of shooting I anticipate doing,
    and I have a few different packs to use based on whether I'm mostly
    shooting from a vehicle or doing extensive hiking.

    <p>

    For day hikes I try not to carry a camera backpack weighing more
    than about 20 lbs, excluding the tripod which is carried with a
    shoulder sling. This means something like a Lowepro Mini Trecker.
    I'm middle aged, but in reasonably good shape, and can hike for
    hours with such a setup. It means leaving something like the 400mm
    f/4 at home though.

    <p>

    The MiniTrecker is an airplane carry-on, and the tripod goes in a
    dufflebag with my clothes.

    <p>

    For my recent Yellowstone shoot ( http://www.luminous-
    landscape.com/yellowstone-winter.htm ) for example, where most of
    the shooting was from the vehicle, I use the Lowepro Roadrunner AW,
    a large rolling backpack style bag, which held everything I needed
    for a week-long shoot, including 2 MF bodies and 5 lenses, one of
    which was the Pentax 400mm f/4 ED(IF).

    <p>

    The bag weighed 55 lbs (I know because the airline weighed it). I
    could pack it for a few hundred yards, and did, but that's about it.
    It's sturdy enough to be checked as lugged and because it has wheels
    as well as a pack design, can be wheeled through airports rather
    than carried.

    <p>

    If I'm using this bag and need to hike I simply take what I need and
    put it in the pockets of my shooting vest. The camera and one lens
    goes over my shoulder with the tripod on its sling as always.

    <p>

    Hope this helps.

    <p>

    Bert,

    <p>

    You're quite right. But, if you go back and re-read the article
    you'll see that I did use, and also mentioned, the Manfrotto 359
    Support Arm, which is a must for this type of photography.

    <p>

    http://www.luminous-landscape.com/359.htm

    <p>

    Michael
     
  6. Many people tried the Pentax 67, and gave up, saying that the images
    were not sharp. I found it was true if I used a lesser tripod, say,
    a Bogen 3021 which I did try out. The shutter shock problem of the P67
    demands much heavier support, even with the mirror locked up,
    especially when shooting horizontals. The movement of the shutter mass
    creates an internal torque about the camera's mass center, so it
    actually twists during the shot. This is much less a problem for
    verticals, since ironically since we need to flip it to the side of
    the ball head the torque now has to fight with a much more rigid
    tripod axis. Try to twise your 3021 the both ways, and you'll
    understand what do I mean. It is by some means a handicapped system,
    on which one can't fire at 1/8 and 1/15, and for which a Grizo 1548 is
    absolutely necessary, even it costs a fortune and offsets a very cheap
    MF system otherwise. However counting in the $1k for the 1548 the
    system is still inexpensive, cheaper than many of my friends 35mm
    outfits. I also use a short aluminum center column with the setup, on
    which I drilled three holes across the center so that whenever I shoot
    I stick through a philips screw driver I always carry, and hung my 25
    lb. (at least) Domke Outpack backpack to weight down the tripod. It
    will look funny, but as a physicist I found nothing substitutes the
    physical weight in the role damping out the shutter vibration,
    especially when shooting horizontal, even the carbon fiber (or wood)
    legs do absorb the vibrations much better than the metal ones. The
    Domke bag is of a "vertical" design so that I can access my gear while
    it is on the center column, very convenient. I would feel unsecure
    whenever my set up is not weighted down by the heavy bag, especially
    in windy days. The results? I routinely enlarge my 6x7cm chromes to
    24x30 on Lightjet, still with details to be seen inches away (many
    viewers sware they are from 4x5 originals), and publications including
    two covers last year. I have found my 200mm plue 2x images sharp
    enough for 16x20s with this set up.
     

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