Mamiya 150mm 3.8 (Shutter, N/L Series) Bent blade?

Discussion in 'Medium Format' started by sauerwine, Oct 20, 2004.

  1. I just purchased a M645 System after 15 years of patient waiting.
    (body, PD prism, 80/2.8, 210/4.0, 55-110/4.5, vivitar 2x, and the 150
    Leaf shutter lens...$850)

    The ONLY problem I've seen on this entire system, is a very slight,
    upward bend- in just one of the shutter blades of the leaf shutter.
    It is at the very tip of the blade- and doesn't appear to interfere
    with the overlapping of the other blades. (The bend is at less than 5
    degrees towards the filter side, and less than 3/32" in length.)

    I also notice that there are a set of secondary, (non-aperature, of
    course,) blades which don't ever close into the center of the lens. I
    suspect these are support blades, but there are three visible from the
    filter side, and only one from the rear element side. There are no
    wear marks on any of these blades, indicating that they are, indeed,
    running untrue.

    I haven't witnessed a lag in the shutter, (Seiko #0,) at all, and have
    just acquired the equipment today. I'm trying to get some opinions in
    case I might have to talk "price adjustment." (I believe I got a
    decent deal, but we discussed this possibility before I paid.)

    Does anyone have any experience with such a problem? Is is normal?
    Is it a common problem, due to setting the shutter incorrectly, or
    basic fiddling around with things in the wrong order?

    I ask such dumb questions, because the seller said he only ever used
    it once, and condition tends to support it. The lens is spotless
    everywhere, and the mount looks like I may have been the only one to
    connect it, ever, to a camera body! (Even the sharp edges of the
    bayonette mount, where the body stops would hit, have less than .010"
    of paint lightly scratched from them. There are no scratches elsewhere.)

    Thanks for your time, and any help you can give or suggest!

  2. i believe the slight upwards bend is normal for the shutter since the hasselblads that i own have them also.

    i don't know about the other problems though...
  3. My Mamiya C330 has the bend, and I believe it's to guarantee that the blades never foul on closing. TTBOMK, it's normal.
  4. What you are describing is the latter model Seikosha anticrash shutter. Earlier shutters were susceptible to the shutter blades crashing into each other upon closing. To solve this problem, Seikosha tried various methods of bent blade tips and spacers under some or all of the blades. I have several shutters that have a bent tip on blade 1 and 6. Blade 6 sits directly on top of blade 1, so when looking at the front or rear of the shutter you only count 5 blades. There is a spacer that is slightly thicker than a blade the sits between blades 1 and 6. There are shims under blades 2 and 3. All of these were intended to clear certain parts of the shutter body castings and/or to prevent the shutter blades from crashing. I have other shutters from the same model of camera that are arranged deferently. The manufacturer works at constantly improving the shutters and it is not uncommon that the minor improvements are not advertized to the consumer.

    In short, don't worry about how your shutter blades look, if it works then leave it alone.
  5. Thanks much, guys!

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