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  1. #41

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    Hi Leigh,

    The laws of optics do apply to real lenses. However, let's agree to disagree.

    Jerry
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  2. #42
    Leigh B's Avatar
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    Hi Jerry,

    And the laws of economics trump the laws of optics when it comes to deciding what's available in the marketplace.

    As I said previously, my comments were comparisons of actual products on the street, not on what was or was not possible.

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

  3. #43
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    Quote Originally Posted by PKM-25 View Post
    Two of these just went for $399 each on ebay...I was tempted but they have the same optimum 6X mag as the vanilla flavored Rodagon 150mm. At 6x from 4x5, that is a 24" x 30", out of my reach until I can get a bigger home to build a proper darkroom in and use a drop table with my 45MXT. Add to that the front is bigger and longer and I would have to re-design my contrast filter holder or use larger ones in between the light source and neg, a big no-no if you do split grade printing not to mention inviting more possibility of dust.

    I also have the 135mm Rodagon for 20" x 24" without needing a drop table, the largest size I can practically do until I get a larger pad.
    You're sticking filters under the lens? They will affect your sharpness significantly more than any choice of enlarger lens you might make.

  4. #44

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    Quote Originally Posted by DREW WILEY View Post
    Want the Rolls Royce? Take out a second mortgage and buy a 210 Apo El Nikkor (...)
    Could this Mercedes cut the 15x job?

    Click image for larger version. 

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  5. #45
    ic-racer's Avatar
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    Quote Originally Posted by polyglot View Post
    You're sticking filters under the lens? They will affect your sharpness significantly more than any choice of enlarger lens you might make.
    I strongly disagree. Poor lens choice will result is blurry corners or lack of complete coverage.
    Using a Peak 1 grain focuser I cannot detect any change in grain sharpness with an Ilford MG acetate filter in the light path below the enlarger light.

  6. #46
    Steve Smith's Avatar
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    I have a Componon 150mm f 5.6. What is the difference between this and a Componon S?


    Steve.

  7. #47
    Steve Smith's Avatar
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    Quote Originally Posted by ic-racer View Post
    The makers of 135mm enlarging lenses for 4x5 film have not heard of your rule.
    They're going to be really annoyed when they do!


    Steve.

  8. #48
    ic-racer's Avatar
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    Quote Originally Posted by darkroom_rookie View Post
    ic-racer,

    I'd be very interested to know if the charts below can give more insight on the lens' performance.
    Especially if this lens is a good performer at 15x.

    Attachment 55964

    Thanks.
    The MTF shown (Rodagon?) demonstrates excellent performance at 6x. I suspect it would also be good at 15x but that is based on my experience with the usual 6-element lenses commonly used and not based on any info in the chart presented.

  9. #49

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    Quote Originally Posted by ic-racer View Post
    The MTF shown (Rodagon?) demonstrates excellent performance at 6x. I suspect it would also be good at 15x but that is based on my experience with the usual 6-element lenses commonly used and not based on any info in the chart presented.
    Yes, a Rodagon, 120 WA.

  10. #50
    ic-racer's Avatar
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    I have a Componon 150mm f 5.6. What is the difference between this and a Componon S?


    Steve.
    This chart shows the technical differences. This particular chart is from a point in time when they still made both types. Both are 6 element.
    I have quite a few of both but only matching focal lengths in 150mm and 80mm to compare side-by-side. I cannot detect any difference in prints but I do not have any MTF curves of the non-"S" lenses to post for a true objective comparison.

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