What is the Cosine Rule for Lighting? How to Calculate Light Levels at an Angle from the Source

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  • čas přidán 4. 07. 2024
  • In this video we look at how to calculate light levels at a point that is not directly below the light source. We look at the cosine rule for illuminance or lighting, it involves knowing the angle from the light source to surface and how this fits in with the inverse square law.
    These videos are designed to help learners who are studying any kind of electrical course including City and Guilds 2365, 5357 and 8202 as well as the EAL Diploma in Electrical Installation.
    #joerobinsontraining #Electricaltrainingvideos #scienceandprinciples

Komentáře • 35

  • @paulbarber9854
    @paulbarber9854 Před 3 lety +6

    I just want to tell you, Joe. I recently took a job as an agent for lighting companies in the United States. I've spent the past two months cramming every bit of knowledge I could into my brain -- about lighting and electricity. None of my college education was in technical fields, so I felt at a bit of a disadvantage. After two months of doing this for 10+ hours a day, I have learned a lot from various sources. But none as much as from your series -- which I've watched most of the way through twice. Even though much of your series doesn't directly relate to lighting, it's amazing to me how helpful it's been. I was a professional educator myself for 25 years, and I have to say that I've never seen anyone more talented at it than you are. Thank you so much for posting these!

    • @JoeRobinsonTraining
      @JoeRobinsonTraining  Před 3 lety +3

      Oh wow, what a great comment, I'm so glad thay you're finding them helpful Paul, there's some more lighting content on the way so stay tuned. Again thanks for the comment, it's this kind of thing that keeps me going. 😊

  • @patientson
    @patientson Před 4 lety +3

    Good morning, Mr Joe. I will continue to thank you for your time, great mind and your intuition and support you have towards helping others. Thank you for doing this video too..
    Thank you.

  • @katiebarnes9346
    @katiebarnes9346 Před 3 lety

    This was so well explained, thank you!!

  • @newbie8051
    @newbie8051 Před 9 měsíci

    Ah thanks for the explanation, glad to have this subject as an elective in my undergrad degree.

  • @missnogol7738
    @missnogol7738 Před 2 lety

    Good Effort , It's been really Helpful, THANKS

  • @user-13y578g
    @user-13y578g Před rokem

    very good and clear explanation, thank you!

  • @Mehlsack93
    @Mehlsack93 Před 2 lety

    Great! „What we're interested in is the angle from perpendicular“.

  • @LindaTheLearner
    @LindaTheLearner Před 4 lety +1

    Thanks for more excellent tuition Joe 🙏

  • @merijosipin
    @merijosipin Před 2 lety

    Thankyou so much for this

  • @2958918
    @2958918 Před 3 lety +3

    in case you want to use the height , simply multiply by "cos(theta)^3" instead of "cos(theta)"

  • @musangobi2079
    @musangobi2079 Před 4 lety +1

    Easy and clear explanation.

  • @muhammadbasil8259
    @muhammadbasil8259 Před 9 měsíci

    Thanks

  • @tuyen_phan94
    @tuyen_phan94 Před 2 lety +1

    Can you do a course on determining the luminous flux of a lamp?

  • @religiousblackman697
    @religiousblackman697 Před 4 lety +1

    amazing video from the U.S

  • @RWATraineeElectrician
    @RWATraineeElectrician Před 4 lety +1

    Thanks for the video Joe. I'm glad I invested in a scientific calculator 😎

  • @andrewmurschel2608
    @andrewmurschel2608 Před 2 lety +1

    Great video!
    Something I've been struggling with for a while, maybe you can help. When you changed the angle of incidence from the torch, the pool of light changed into a more elliptical shape. I'm looking for a mathmatical way to determine the major axis of that ellipse, given the beam angle, distance, and z-angle.
    Practical example: a theatrical spotlight pointed at the stage, from a position out over the audience.
    I've found a geometric way to do it with some basic trig, but I'm specifically interested in the relationship between z-angle and the major axis. (Eccentricity?)
    Any help is greatly appreciated!

  • @obonetsedikaelo8435
    @obonetsedikaelo8435 Před 2 lety

    Can you do.. Calculations of shunt resistor and multiplier resistor

  • @electrodellinstallations556

    Good video Joe. When I did this long time ago we kept the original height (d) the same even for working out the angles? Is this a newer way. Don’t suppose it makes a huge difference 👍

    • @JoeRobinsonTraining
      @JoeRobinsonTraining  Před 4 lety

      Cheers Matt, you definitely need to use the distance from source to surface in a straight line, not just the height!

  • @MsTommyknocker
    @MsTommyknocker Před 2 lety

    E is illuminance?? Thanx for the upload

  • @reinielantonio2278
    @reinielantonio2278 Před 3 lety

    Hi i have a question, Why other formula for Illuminance is look like this E=(Icos²X)/(d²) Thank you for your time. Have great day 😁

  • @wongweiloong4726
    @wongweiloong4726 Před 2 lety +1

    hi how would u calculate the illuminance at a point when 2 lamps are on, given the angle, distance and the luminous intensity of the 2 lamps?

    • @JoeRobinsonTraining
      @JoeRobinsonTraining  Před 2 lety

      Like this... czcams.com/video/N0ohNNAJoKc/video.html hope it helps. 😊

  • @nontsingiselomvango2130
    @nontsingiselomvango2130 Před 3 lety +1

    How to calculate illuminance between two lamps

    • @JoeRobinsonTraining
      @JoeRobinsonTraining  Před 3 lety

      Great question, try this video:
      czcams.com/video/zCCW2K6qaYM/video.html
      Hope it helps. 😊

  • @ricardodias5482
    @ricardodias5482 Před 3 lety

    Im about to finish my math degree in portugal and i need help calculating veiling luminance calculation in a road can you help me ? i got 2 weeks

  • @lileenleen
    @lileenleen Před rokem

    I'm learning this for illustration, II need to have more realisitic lighting lmao

  • @helendu5241
    @helendu5241 Před 3 lety

    11:57 I thought you used COS already , then you stick with 4 meter instead of 5 meter?