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  1. #11

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    Quote Originally Posted by Tom1956 View Post
    Why would I be kidding? The 2 lenses are of the same diameter. Lay the doublet down flat, presuming the back lens is either flat or concave, and then block it on 4 sides. If the back lens is convex, I have an obvious problem. I haven't disassembled the lenses yet to see. Might have to make another plan. But that plan isn't going to include spending money I don't have. I always find a way.
    Tolerances in optics are not measured with a micrometer but in wavelengths of light. They're worse than watches. But - if you botch a recementing job with balsam you get all the second chances you need. You could make V-blocks on a milling machine, lapping them to the final finish - and they'd be just as good as the Starrets for recementing. For this purpose the vee need not be precisely 90 degrees, it just needs to be straight, smooth, and at 90 degrees to one end of the block.

  2. #12
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    It sounds to me like you've got me doing the job with the lenses upright, rather than horizontal. You must be knowing the back lens is convex and it therefore won't lay flat.

  3. #13
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    I wonder if a dumb idea wouldn't be something as simple as a radiator hose clamp.

  4. #14

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    Not neccesarily. I'd use a surface plate for this because I have a small one. I'd place the cemented pair flat on the plate, if both surfaces were convex I'd make a ring and lap it flat/parralel. Use the V-blocks against the edges to keep everything centered, and give the balsam a few weeks at least to set. Personally I'm hesitant to use UV curing cement, it's much more difficult to decement the lenses.
    I recemented a R-R on an old Kodak folding camera using balsam from local trees. The camera was my mother's father's, I now have pictures of her taken with that same camera over a span of almost 80 years.

  5. #15

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    Quote Originally Posted by Tom1956 View Post
    I wonder if a dumb idea wouldn't be something as simple as a radiator hose clamp.
    Now I know you're joking. Right? You're joking, right?

  6. #16
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    I've already ordered the Canadian Balsam. If I foul up the job, I'll boil it and start over.

  7. #17
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    Revision of Thread and question

    Upon disassembling this Rolleiflex 3.5E with Xenotar, I find the front element is a single piece of glass, not a cemented doublet. And it appears that it could possibly be etched on the front surface, or perhaps fractured coating makes it appear that way. I cannot tell because I do not have adequate magnification to see that closely. Obviously this piece of glass needs to get in the hands of an expert. It may turn out to be irreparable. This seems a dismal end to an otherwise good camera, so I float the matter out there for input. Thank you.

  8. #18
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    You could use the article I wrote: http://www.fotomozaic.ro/
    Your tongue is probably sensitive enough that you won't need to worry about clamps or jigs. At least mine has always worked just fine for work like this. Students of dentistry learn early just how tiny of a difference in height the tongue can detect. I offered to send Canada Balsam to anyone who needed it in another thread weeks ago. When that is gone I also have some very high grade rosin (some from Honduras, some from China, and more from other places). It will work just like Canada Balsam, actually.
    If the element is etched on the front surface, you will have a much more expensive and complex repair. Good luck, however.
    Jon

  9. #19
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    Quote Received--$225.

    So I've received the quote from Focal Point on the polishing and re-coating of the front element only of the Rolleiflex Xenotar 3.5 lens element. I have the element extracted from the camera already. All it is is a single little thin piece of glass. And it's $225.00? Really? C'mon. Surely there's an alternative. $225? I wonder what other ideas there might be on this.

  10. #20

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    Quote Originally Posted by Tom1956 View Post
    So I've received the quote from Focal Point on the polishing and re-coating of the front element only of the Rolleiflex Xenotar 3.5 lens element. I have the element extracted from the camera already. All it is is a single little thin piece of glass. And it's $225.00? Really? C'mon. Surely there's an alternative. $225? I wonder what other ideas there might be on this.
    Do you have any clue what that entails? You can always do it yourself...

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