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Thread: 360mm f4.5 Schneider Xenar to Sinar board, part 1

  1. #1

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    360mm f4.5 Schneider Xenar to Sinar board, part 1

    Had this lens for a while, decided to mount it onto a Sinar lens board. eBay purchase, appears to have been used in a industrial or military application as the lens came with an unusual collar and mount with a long tube extension. That part got cut down to a 0.90" collar to raise the flange of the Xenar high enough to clear the aperture pin on the Sinar shutter. Once that was done, the process of cutting a 4.402" hole in the Sinar board. This began with setting up the Sinar board in the lathe with a four jaw chuck, small boring bar.
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    Hole roughed out.
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    Finish bore the hole to 4.402" with a BIG solid carbide insert boring bar.
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    Bernice

  2. #2

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    360mm f4.5 Schneider Xenar to Sinar board, part 2

    Sinar lens board hole bored to 4.402". Set up the 360mm Xenar lens collar in a rotary table, fit the lens board to the collar getting it ready to drill and tap four #4-40 into the collar and #4 clearance holes (0.130") into the lens board with countersinks.

    Set up the lens collar and lens board:
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    Drill for# 4-40 tap four places, 90 degrees apart, do not remember what the screw circle dimension was.
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    Remove the lens board, tap all four holes to# 4-40.
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    Drill# 4-40 clearance holes and countersink them.
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    Bernice

  3. #3

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    360mm f4.5 Schneider Xenar to Sinar board, part 3

    Assembled the 360mm f4.5 Xenar lens collar with flange to the Sinar Lens board. The bare aluminum areas are darkened with a black sharpiee marker.
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    What the finished 360mm f4.5 Xenar looks like mounted to the Sinar Lens board on a Sinar P2.
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    ~Why the Portrait oriented images upload and become landscape, no idea.. This is an admin question-problem.~

    Bernice

  4. #4

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    Re: 360mm f4.5 Schneider Xenar to Sinar board, part 1

    Very nice work Bernice!

    I've often thought a 4 jaw chuck with top jaws would be a useful thing to have. It would open up the possibility making custom top jaws for holding odd shaped work pieces. Probably easier than setting up on a faceplate.

    Guessing that's an 8 inch chuck based on the size of the (Sinar) lens board. Is that right?

    David

  5. #5

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    Re: 360mm f4.5 Schneider Xenar to Sinar board, part 1

    Yes, that is a eight inch four jaw chuck. Four jaw independent chucks are often better than a three jaw as it can be adjusted accuracy requirements of a part to be worked on. They can hold irregular shapes and have much higher holding power than a three jaw.

    Example of what is involved to have a machinist or similar shop mount a BIG lens on to a board, it is machinery, tooling skill-labor intensive to do this properly.
    Precision and accuracy of how a lens is mounted can affect the optical performance of a lens.


    Bernice



    Quote Originally Posted by David Lindquist View Post
    Very nice work Bernice!

    I've often thought a 4 jaw chuck with top jaws would be a useful thing to have. It would open up the possibility making custom top jaws for holding odd shaped work pieces. Probably easier than setting up on a faceplate.

    Guessing that's an 8 inch chuck based on the size of the (Sinar) lens board. Is that right?

    David

  6. #6

    Re: 360mm f4.5 Schneider Xenar to Sinar board, part 1

    Beautiful work Bernice

    I have had some of my Norma lenses forward mounted in various ways.

    Photo machining mounts can be expensive. I'd love some day to get a lathe and vertical mill.

    300mm F4.5 Xenar Norma by Nokton48, on Flickr

    This is my Norma mounted 300mm f4.5 barrel Xenar. A clockmaker friend cut down an enlarging cone of some sort. and metal epoxied it to a Norma board. Then cut down the flange making it into a thin-mount retaining ring, which just fits inside the cone.

    This lens is great for 5x7 portraiture, I would like to find the 360 Xenar and the 420 Xenar. The ones I have seen have cost the moon.
    Flikr Photos Here: https://www.flickr.com/photos/18134483@N04/

    “The secret of getting ahead is getting started.”
    ― Mark Twain

  7. #7

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    Re: 360mm f4.5 Schneider Xenar to Sinar board, part 1

    Schneider Xenar from this era is one of the lesser know really good Tessar lenses. There was a time when Xenars were considered undesirable due to the Xenar being a lower contrast, optimized for larger apertures like f8 which was not what the commercial ad marketing images from the 1980-90's were mostly about. Regardless, they remained preferred and desirable by folks doing portraits and such.

    This 360mm Xenar joins the 210mm, 300mm (head-shoulder on 5x7 lens) and the 480mm which was purchased decades ago when few if any wanted a lens like this. It was once used for 8x10 and not used much at all these days.
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    Using these barrel lenses is easy due to the Sinar Shutter and the Sinar system.


    The Tessar formula continued on with GOOD examples made by Fuji, Komura and others.


    Bernice

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