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  1. #1

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    Home invention Hasselblad Mirror Checking?

    Anybody who has kept up with my camera repair escapades poorman-style could have expected me to cook up another scheme. Working on Hasselblads seems to have risen to the top of these endeavors. By "risen to the top", I hope it doesn't end up as merely more internet pond scum.
    Working on Hasselblads require factory made and approved jigs, fixtures, and tools that few people can own. And
    usually these same people have factory training. Far and above us mere mortals
    But careful attentive work CAN be done, perhaps as within 5 total percent error of factory work. Certainly 8% at the outside.
    Now that this verbal windage has made my self-expectations a standard for home-made excellence, I have an idea. On the gliding mirror models, What if a home made jig made of perhaps PVC pipe fittings or other common materials could be fabricated or fashioned to shoot a cheap laser toy dead center of the bayonet flange, at a near-perfect perpendicular angle right down the camera's throat? Should not that beam end up near dead center of the ground glass? Obviously if the mirror stops were off, the beam would end up higher or lower.
    Al comers welcome to shoot down my boob plan. Or approve it. Gratitude, HTF

  2. #2

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    Make that 2% error and 5% max. So far, I'm within .04mm on a 71.40 measurement in setting up the chassis.

  3. #3
    lxdude's Avatar
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    The screen height adjustment at all four corners would have to be dead nuts and you would have to know that it is.
    Last edited by lxdude; 03-24-2014 at 01:51 AM. Click to view previous post history.
    I do use a digital device in my photographic pursuits when necessary.
    When someone rags on me for using film, I use a middle digit, upraised.

  4. #4

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    Quote Originally Posted by lxdude View Post
    The screen height adjustment would have to be dead nuts and you would have to know that it is.
    I had already considered that. At this stage in calibration, all 4 screws would be bottomed out, for the better or worse of the plan. First a 71.40mm chassis length was done, within the tolerances of my more crude dial caliper (instead of the Hass fixture). I was happy there. Right now I'm working on fashioning a ground glass to check lens infinity stop. But moving on, it seems to me mirror angle comes next. And the only way to zero in on that would be by screen squareness to the chassis assembly. Necessarily all one CAN do is bottom out the screen pegs and hoping for the best on that count, so you can shoot your mirror angle. Right? Then adjust your screen pegs last.

  5. #5
    lxdude's Avatar
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    I do use a digital device in my photographic pursuits when necessary.
    When someone rags on me for using film, I use a middle digit, upraised.

  6. #6

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    Thanks, it was the 503 repair manual. I've read all those available on the free internet already. They call for the Hass fixtures, tools, and jigs. And I understand their use.

    BTW--at this time I'm dealing with a 553 ELX.

  7. #7
    ic-racer's Avatar
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    On my 35mm cameras with easily adjustable mirrors, I spend some good time observing the horizon at the top, and bottom and middle of the viewfinder, then adjust as needed.

  8. #8

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    What do you mean observing the horizon?

  9. #9
    ic-racer's Avatar
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    Horizon being a surrogate for infinity. If the lens is collimated to the film plane, then focus errors observed with the focus screen signify that the screen and/ or mirror would be off. To set the mirror angle I observe the horizon at the top of the screen and at the bottom. Should be just as clear and sharp in both cases. If not, tweak with a screwdriver (in those cameras with the capacity).

  10. #10

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    Understood, ic-racer. But I have a couple problems with that. First, I have to get in my truck with tripod, camera, and tools and drive a long way before there is any horizon. Further, I've been doing these sorts of home-baked ideas for too long, and am moving on in my repair studies to wanting to devise bench-testing variations of expensive and unobtainable factory fixtures and jigs. And do better work than these slow cumbersome and imprecise tripod tests on a pretty day.
    I wish I could better understand the construction of the official Hasselblad mirror jig, but have never seen one. But I can surmise how it must work and come up with a variation. Reverse engineering, I suppose.

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