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  1. #21
    Bob Carnie's Avatar
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    I have a 240 , 180 , 150 mm enlarger lenses that I could use, I also have a 150 mm camera lens.
    Would any or all of these work?
    Quote Originally Posted by jimgalli View Post

    4 racers

    Made with a 9" petzval type. My strange depth of field requirements are not the norm, nor for everybody, but just to point out that with this type of photography bellows extension and stability is really more the problem to solve than which lens. In this case I've used an ancient studio camera with 8X10 back (this may have actually been 5X7!) and a rolling stand with table top for the camera. Stable stable stable, and 36" of bellows to play with, that will not sag.

    I also always tell people to start with the ordinary 150mm Componon that's already on the enlarger. Turn it around backwards. Yes, matilda, at the extensions you'll need for 3X it'll cover 8X10 very nicely, and it'll be operating within it's design parameters.

  2. #22

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    Quote Originally Posted by Bob Carnie View Post
    I have 36 inch of workable bellows ... I am using an old century camera with no shutter, its light tight as I have gone through a few boxes of film as late as last sunday.
    Well, the magic rule is: extension (distance from lens' rear node to film plane) = focal length * (1 + magnification). So the longest lens you can use is 9" and a bit shorter would probably be better. For most lenses, the rear node is near the diaphragm.

    There's another magic rule, to the effect that if the lens is intended to be used at magnifications below 1:1 (that's all taking and enlarging lenses) it should be reversed when used at magnifications > 1:1. The big exceptions are symmetrical (with identical front and rear cells) lenses; this includes Apo-Saphirs (heliar type), some, perhaps not all, dagor types and most if not all dialyte type process lenses.

    Good luck, have fun,

    Dan

  3. #23
    Leigh B's Avatar
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    I have a Fujinon CM-W 180/5.6 in a Copal #1 available in EXC condition for $395 including shipping in CONUS.
    It's an almost-symmetrical design of six elements in five groups. It takes 67mm filters.
    Here's a schematic drawing of the lens: http://www.mayadate.org/pix/Fujinon_CM-W.png

    This is the later EBC-coated version with lettering on the outside of the barrel.
    The IC is 260mm @ infinity (8x10 diagonal is 325mm), so it will cover a range of close-up work, not just 1:1.
    It would even work @ infinity with vignetting of the corners.

    FFL is 170.7mm, so 1:1 requires a bellows draw of 170.7+180 = 350.7mm (13.8").

    I can provide photos if you're interested in it.

    - Leigh
    Last edited by Leigh B; 06-28-2012 at 10:45 PM. Click to view previous post history.
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  4. #24
    Leigh B's Avatar
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    Quote Originally Posted by Dan Fromm View Post
    So the longest lens you can use is 9" and a bit shorter would probably be better.
    Hi Dan,

    Not meaning to quibble, but...

    If you use 1:1 as the close-focus limit, your maximum lens FL is about 1/2 the bellows draw, which would be 18" in this case.

    The other 2xFL (@ 1:1) is in front of the lens and is not involved in the bellows draw calculations.

    - Leigh
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  5. #25

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    Quote Originally Posted by Leigh B View Post
    Hi Dan,

    Not meaning to quibble, but...

    If you use 1:1 as the close-focus limit, your maximum lens FL is about 1/2 the bellows draw, which would be 18" in this case.

    The other 2xFL (@ 1:1) is in front of the lens and is not involved in the bellows draw calculations.

    - Leigh
    Leigh, he wants to go to 3:1

  6. #26
    Leigh B's Avatar
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    OK. I find no mention of 3:1 earlier in the thread.

    - Leigh
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  7. #27

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    Quote Originally Posted by Leigh B View Post
    OK. I find no mention of 3:1 earlier in the thread.

    - Leigh
    See post #18 in this thread.

    Dan "none so blind as he who does not want to see" Fromm

  8. #28
    Leigh B's Avatar
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    Quote Originally Posted by Dan Fromm View Post
    See post #18 in this thread.
    This is getting quite confused.

    Post #18 is by Bob Carnie, not the OP, and he does not mention a 36" bellows.

    Jim Galli mentions a 36" bellows in his response to Bob's post, again not the OP.

    My post was directed at the OP's original question. (Apologies for trying to stay on-topic.)

    - Leigh
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  9. #29

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    Quote Originally Posted by Leigh B View Post
    This is getting quite confused.

    Post #18 is by Bob Carnie, not the OP, and he does not mention a 36" bellows.

    Jim Galli mentions a 36" bellows in his response to Bob's post, again not the OP.

    My post was directed at the OP's original question. (Apologies for trying to stay on-topic.)

    - Leigh
    See posts 18, 19, 21, 23. The OP is long gone, Bob Carnie and I have been discussing Bob's situation. Threads drift. Live with it.

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