Lensmaker's Equation

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  • เผยแพร่เมื่อ 29 ม.ค. 2025

ความคิดเห็น • 18

  • @The_moonlit
    @The_moonlit หลายเดือนก่อน +3

    Okay so Ive also been pondering this question. Some books and Micheal van Beizen (youtuber) say the lensmaker equation is (1/R1-1/R2) but he says right here its (1/R1+1/R2).
    I think this just arises from the different definitions of a negative and positive RoC. The (1/R1-1/R2) variation defines a positive RoC as any surface where the belly faces the left, and a negative RoC where the belly faces the right.
    In (1/R1+1/R2) however, the definition for positive and negative RoC depends on if its convex or concave. So R2 in the first variation is negative because the belly faces the right, but here its positive because its convex.
    Whatever one of these formulas you use, they both work, just be aware that they use different rules for what is a negative and positive RoC.

  • @VirjScarlett
    @VirjScarlett 9 ปีที่แล้ว +10

    Thank you. Tomorrow will be our finals.
    In just 5 minutes you have explained it very well.

  • @sandiplivingandlife
    @sandiplivingandlife 3 ปีที่แล้ว +2

    I am from India and your lecture is excellent 👍

  • @wongyeen6419
    @wongyeen6419 หลายเดือนก่อน

    Very clear explanation! Thanks you for ur lecture.

  • @akylakanov2764
    @akylakanov2764 8 ปีที่แล้ว +1

    Thank you so much!!! I wish you were my physics teacher. Love your lectures!!!

  • @lalitjoshi4729
    @lalitjoshi4729 6 ปีที่แล้ว +5

    We have studied it in books as In bracket(1/r1-1/r2)

    • @The_moonlit
      @The_moonlit หลายเดือนก่อน

      Okay so Ive also been pondering this question. Some books and Micheal van Beizen (youtuber) say the lensmaker equation is (1/R1-1/R2) but he says right here its (1/R1+1/R2).
      I think this just arises from the different definitions of a negative and positive RoC. The (1/R1-1/R2) variation defines a positive RoC as any surface where the belly faces the left, and a negative RoC where the belly faces the right.
      In (1/R1+1/R2) however, the definition for positive and negative RoC depends on if its convex or concave. So R2 in the first variation is negative because the belly faces the right, but here its positive because its convex.
      Whatever one of these formulas you use, they both work, just be aware that they use different rules for what is a negative and positive RoC.

  • @madhvinirola3842
    @madhvinirola3842 9 ปีที่แล้ว +2

    best I ever watched

  • @ahmedhegazy699
    @ahmedhegazy699 5 ปีที่แล้ว +3

    But what’s the meaning of a positive focal length? Does it collect the parallel incident rays or spread them?

    • @xr0nus855
      @xr0nus855 ปีที่แล้ว

      Positive focal length is due to the sign convention according to Cartesian plain the left side is negative so if the focal length is on the left side it is negative if it's on the right side it is positive

  • @Alppzleest
    @Alppzleest ปีที่แล้ว +1

    Beat video ever seen thank u sir

  • @TheCdub2011
    @TheCdub2011 7 ปีที่แล้ว +1

    Solid Video! so if convex surfaces are positive and concave surfaces are negative, should R1 be negative if the lens is observed from the right side of the board ( C1 toward C2).

  • @ProfessorElectronic
    @ProfessorElectronic 5 ปีที่แล้ว +2

    What does a negative focal length means?

    • @tunistick8044
      @tunistick8044 3 หลายเดือนก่อน +1

      it means the focus point comes before the center of the lens

  • @gustavorios6956
    @gustavorios6956 4 ปีที่แล้ว +1

    how can i demostrate this equacion?

    • @tunistick8044
      @tunistick8044 3 หลายเดือนก่อน

      with drawibg the graphs of the vergence in function multiples variables related to the lens

  • @PhysicalSciences
    @PhysicalSciences ปีที่แล้ว +1

    Groovy

  • @Ryan-yq8sf
    @Ryan-yq8sf 3 ปีที่แล้ว +1

    god bless