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Thread: Finding True Curve

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    Finding True Curve

    Hi,

    Using 1.53 as the reference for index, what will the true curve be for a Nominal base of 2.50 with a Front Radius of 203.87? I have a formula to divide by 530 but it doesn't make sense the final number of 3.84

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    Master OptiBoarder lensgrinder's Avatar
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    Quote Originally Posted by lana c View Post
    hi,

    using 1.53 as the reference for index, what will the true curve be for a nominal base of 2.50 with a front radius of 203.87? I have a formula to divide by 530 but it doesn't make sense the final number of 3.84
    D = (n-1)/r
    2.5 = (n-1)/0.20387
    0.509675 = n - 1
    n = 1 + 0.509675
    n = 1.509675

    F1 = (2.5 X 0.509675)/0.53
    F1 = 2.4041273585

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    Quote Originally Posted by lensgrinder View Post
    D = (n-1)/r
    2.5 = (n-1)/0.20387
    0.509675 = n - 1
    n = 1 + 0.509675
    n = 1.509675

    F1 = (2.5 X 0.509675)/0.53
    F1 = 2.4041273585
    Thank you!

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