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  • Maggnitude????????

    From Jean Mario Charest@21:1/5 to All on Wed Nov 1 05:16:03 2023
    Hello, I calculated the theoretical magnitude with the following formula 2.1+5.0xlog(telescope diameter) and I have the following results:
    51mm (2'') = 12.12 absolute theoretical magnitude. And I check on different sites and they give me 10.5 absolute theoretical magnitude.

    Also I took the formula which was announced in 1947. Which is as follows:M = m – 2 + 2.5 x log (D x T x G)
    M: limiting magnitude of the instrument
    m: visual limit magnitude (around 6 depending on the quality of the sky)
    D: instrument diameter in mm
    T: telescope transmission (typically 0.6 to 0.8)
    G: magnification used.

    And that gives me, with a magnification of 10X, M=19.85!

    These are the formulas used to calculate possible observable magnitudes.

    Help me understand please!

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  • From W@21:1/5 to Jean Mario Charest on Wed Nov 1 08:05:30 2023
    On Wednesday, November 1, 2023 at 8:16:06 AM UTC-4, Jean Mario Charest wrote:
    Hello, I calculated the theoretical magnitude with the following formula 2.1+5.0xlog(telescope diameter) and I have the following results:
    51mm (2'') = 12.12 absolute theoretical magnitude. And I check on different sites and they give me 10.5 absolute theoretical magnitude.

    Also I took the formula which was announced in 1947. Which is as follows:M = m – 2 + 2.5 x log (D x T x G)
    M: limiting magnitude of the instrument
    m: visual limit magnitude (around 6 depending on the quality of the sky)
    D: instrument diameter in mm
    T: telescope transmission (typically 0.6 to 0.8)
    G: magnification used.

    And that gives me, with a magnification of 10X, M=19.85!

    These are the formulas used to calculate possible observable magnitudes.

    Help me understand please!

    Try this one: https://www.cruxis.com/scope/limitingmagnitude.htm

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From W@21:1/5 to Jean Mario Charest on Wed Nov 1 08:03:38 2023
    On Wednesday, November 1, 2023 at 8:16:06 AM UTC-4, Jean Mario Charest wrote:
    Hello, I calculated the theoretical magnitude with the following formula 2.1+5.0xlog(telescope diameter) and I have the following results:
    51mm (2'') = 12.12 absolute theoretical magnitude. And I check on different sites and they give me 10.5 absolute theoretical magnitude.

    Also I took the formula which was announced in 1947. Which is as follows:M = m – 2 + 2.5 x log (D x T x G)
    M: limiting magnitude of the instrument
    m: visual limit magnitude (around 6 depending on the quality of the sky)
    D: instrument diameter in mm
    T: telescope transmission (typically 0.6 to 0.8)
    G: magnification used.

    And that gives me, with a magnification of 10X, M=19.85!

    These are the formulas used to calculate possible observable magnitudes.

    Help me understand please!

    You should probably be using Base10 Log.

    Try again, doing each operation one at a time.

    These calcs are only estimates. There are too many variables in play.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jean Mario Charest@21:1/5 to All on Wed Nov 1 10:32:59 2023
    Le mercredi 1 novembre 2023 à 11 h 05 min 33 s UTC-4, W a écrit :
    On Wednesday, November 1, 2023 at 8:16:06 AM UTC-4, Jean Mario Charest wrote:
    Hello, I calculated the theoretical magnitude with the following formula 2.1+5.0xlog(telescope diameter) and I have the following results:
    51mm (2'') = 12.12 absolute theoretical magnitude. And I check on different sites and they give me 10.5 absolute theoretical magnitude.

    Also I took the formula which was announced in 1947. Which is as follows:M = m – 2 + 2.5 x log (D x T x G)
    M: limiting magnitude of the instrument
    m: visual limit magnitude (around 6 depending on the quality of the sky) D: instrument diameter in mm
    T: telescope transmission (typically 0.6 to 0.8)
    G: magnification used.

    And that gives me, with a magnification of 10X, M=19.85!

    These are the formulas used to calculate possible observable magnitudes.

    Help me understand please!
    Try this one: https://www.cruxis.com/scope/limitingmagnitude.htm
    =====================================================================================
    Yes Mr. W. The site you gave me the link seems to be the ideal site for calculating the magnitudes of Newton type telescopes, telescopes and SCTs. That answers my questions. I found 2 formulas on Wikipedia but they seemed to be so so!

    This site seems to be the right one, thank you Jean-Mario Retired engineer.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)