https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-sound-india/in-in-reflections-echoes-and-reverberation/v/echoes-and-reverberations 2020-06-23T07:22:40Z Echoes and reverberations Let's learn what Echoes and reverberations are. We will also see how to reduce reverberations as they could be pretty annoying Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/6axEv22HcHOGefCvwYLMnaPkZUjbK39Iu7pae43KGPq-uv6_EITGpQlmkD9DYhh9MPUa89WxyunYbRBAYViTYag9 Echoes and reverberations Let's learn what Echoes and reverberations are. We will also see how to reduce reverberations as they could be pretty annoying https://cdn.kastatic.org/ka-youtube-converted/LR-AYApQbNE.mp4/LR-AYApQbNE.mp4 537 Uses of light and sound https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-sound-india/in-in-reflections-echoes-and-reverberation/v/minimum-distance-for-echo 2020-06-23T07:22:41Z Minimum distance for echo How far should an obstacle be to hear an echo? Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/y7ItbO4qOznD-U7r7ggpWlpAcgCOwAuvMWmgl2CXDfAiLat-_KvHaLhNldgJKzEx1ldFJw9vQLVx3kHJPx4HY4s Minimum distance for echo How far should an obstacle be to hear an echo? https://cdn.kastatic.org/ka-youtube-converted/LnZSnlQ7shs.mp4/LnZSnlQ7shs.mp4 492 Uses of light and sound https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:sound-waves/x0e04e0cb682fb793:echos-and-reverberation/e/echo-and-reverberation 2026-03-12T00:50:35.110583553Z Echo and Reverberation Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-sound-india/in-in-ultrasound/v/echolocation-sonar 2020-06-23T07:22:42Z Echolocation & S.O.N.A.R Let's learn how animals and ships use echoes to 'see' the world around them. Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/apmkAW-lPhTl4tZfgvWk0zAgcLQhZsg2fPIR1r8cvPibjWf_DYZUvgJ1bFVMXYv8ZiPFuECJGsb1uMo4zH9wncs Echolocation & S.O.N.A.R Let's learn how animals and ships use echoes to 'see' the world around them. https://cdn.kastatic.org/ka-youtube-converted/q_mEFtOGESA.mp4/q_mEFtOGESA.mp4 541 Uses of light and sound https://www.khanacademy.org/science/physics/mechanical-waves-and-sound/sound-topic/v/ultrasound-medical-imaging 2021-02-07T17:14:00Z Ultrasound medical imaging Ultrasound medical imaging (also known as sonography) is a diagnostic imaging tool that uses high-frequency sound waves to create images of structures in the body. Ultrasound images are captured in ​real time​ using an external probe and ultrasound gel placed directly on the skin. They can show things that a still image like an X-ray cannot, such as blood flow or organ movement. Ultrasound images are highly useful in the diagnosis and treatment of many diseases.  David SantoPietro video https://cdn.kastatic.org/googleusercontent/PlwLj88Kvn9N62rC6LxSN4TlSqNCgYPnmav1OcMjOp55WoM68UQvsx8cgI7p3s_8nqQWFQkAjeUHPZKW-W4JqlQ_ Ultrasound medical imaging Ultrasound medical imaging (also known as sonography) is a diagnostic imaging tool that uses high-frequency sound waves to create images of structures in the body. Ultrasound images are captured in ​real time​ using an external probe and ultrasound gel placed directly on the skin. They can show things that a still image like an X-ray cannot, such as blood flow or organ movement. Ultrasound images are highly useful in the diagnosis and treatment of many diseases.  https://cdn.kastatic.org/ka-youtube-converted/sTcqtljxLOk.mp4/sTcqtljxLOk.mp4 335 Uses of light and sound https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:sound-waves/x0e04e0cb682fb793:ultraosund-and-infrasound/e/uses-of-reflection-of-sound-range-of-hearing 2026-03-12T00:50:35.110583553Z Uses of reflection of Sound and Applications of ultrasound Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/3rd-grade-science-matatag/x54502edf5ba25683:3rd-quartere/x54502edf5ba25683:lesson-4/v/sounds-of-a-land 2020-10-16T22:22:10Z Sound How sound and music are used to bring a land to life. Copyright The Walt Disney Company. video https://cdn.kastatic.org/googleusercontent/ErHac-V-C_rjcAuUN9aRnDB0fJCNGu4Jt3egnxcmnTR8a7aNjycs0nr0UDuEZDVhSE6g3sAFxab7oCHcPfI_TKc Sound How sound and music are used to bring a land to life. Copyright The Walt Disney Company. https://cdn.kastatic.org/ka-youtube-converted/8E0pzGT_6Ug.mp4/8E0pzGT_6Ug.mp4 439 Uses of light and sound https://www.khanacademy.org/science/3rd-grade-science-matatag/x54502edf5ba25683:3rd-quartere/x54502edf5ba25683:lesson-4/a/exercise-8-sound-design 2025-06-30T13:29:48.027734197Z Exercise 8: Sound design What sounds will be heard in your land? article https://www.khanacademy.org/humanities/ap-art-history/start-here-apah/elements-of-art-apah/v/light-and-shadow 2026-04-15T07:20:39.065075359Z Light and Shadow Artists use light to reveal stories and create moods. Henry Ossawa Tanner used light to depict faith in his painting "Two Disciples at the Tomb". Käthe Kollwitz used etching techniques to highlight the horrors of war in "Battlefield". Dan Flavin used fluorescent lights to transform everyday materials into art, as seen in "Monument" for V. Tatlin. video https://cdn.kastatic.org/googleusercontent/zIGBmDv4e6OyT7yGXlkNuVQgbJGadsfu-RjXXfYasDKYyA22m9f_u-OwdCjBjikV86e9-Ut-k3x3CCpVhdImymmB Light and Shadow Artists use light to reveal stories and create moods. Henry Ossawa Tanner used light to depict faith in his painting "Two Disciples at the Tomb". Käthe Kollwitz used etching techniques to highlight the horrors of war in "Battlefield". Dan Flavin used fluorescent lights to transform everyday materials into art, as seen in "Monument" for V. Tatlin. https://cdn.kastatic.org/ka-youtube-converted/PnQv8Di8Ark.mp4/PnQv8Di8Ark.mp4 261 Uses of light and sound https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:waves/x1baed5db7c1bb50b:activity-how-can-light-interactions-be-used-to-create-art/a/activity-how-can-light-interactions-be-used-to-create-art 2026-02-27T18:00:31.886851552Z Activity: How can light interactions be used to create art? Make science come alive in your classroom with this free hands-on activity aligned to middle school standards. article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/art-of-lighting-overview 2023-07-31T16:40:28.830178554Z Art of lighting overview Pixar lighters use virtual digital lights to create mood and story points in animated films. They control light intensity, size, color, and direction to evoke emotions. Soft, warm lights create friendly atmospheres, while harsh, cold lights add tension. video https://cdn.kastatic.org/googleusercontent/3Z_3Jd5js_DoOe1hQipX1yVfiCbKA0b-VtMeDx1eotAIvYWFWXlqyv98Qcs6bnIpRmS8bfd_xrV2s4dLti4iMXo Art of lighting overview Pixar lighters use virtual digital lights to create mood and story points in animated films. They control light intensity, size, color, and direction to evoke emotions. Soft, warm lights create friendly atmospheres, while harsh, cold lights add tension. https://cdn.kastatic.org/ka-youtube-converted/pOeaflcMlVU.mp4/pOeaflcMlVU.mp4 165 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/light-quality 2023-07-31T16:40:28.830178554Z Light quality Discover the art of lighting with Pixar's director of photography, Kim White. Learn how real-world lights influence virtual scenes and explore three key aspects of light quality: intensity, color, and softness. Experiment with light sources, filters, and bounce techniques to create different effects and enhance your understanding of lighting in movies. video https://cdn.kastatic.org/googleusercontent/LOVCqCjfKb3y5exOJ63tblhtU2o1fBNcjeraresHNjDtlnpSApWvuLc1eFouFKxOttE3S8rTR4U4p8nqCBwIUbU Light quality Discover the art of lighting with Pixar's director of photography, Kim White. Learn how real-world lights influence virtual scenes and explore three key aspects of light quality: intensity, color, and softness. Experiment with light sources, filters, and bounce techniques to create different effects and enhance your understanding of lighting in movies. https://cdn.kastatic.org/ka-youtube-converted/k2fYzZLP1HQ.mp4/k2fYzZLP1HQ.mp4 215 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/exercise-1-seeing-light 2025-03-07T16:44:37.328259422Z Activity 1: Seeing light and color article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/lighting-roles 2023-07-31T16:40:28.830178554Z Light roles Discover the roles of light in photography and filmmaking: key, fill, bounce, rim, and kick. Key light shapes the scene, fill light reduces contrast, bounce light reflects off surfaces, rim light outlines subjects, and kick light separates subjects from backgrounds. Master these techniques for stunning visuals! video https://cdn.kastatic.org/googleusercontent/4Gn9Qlx4rZqeVa3GD7hoWvRQTcji59apErGrSLs4t5gEfHE0vWgk1WRdGhI1FUcVL9myGrlToGontcwh_1UGLCjzmA Light roles Discover the roles of light in photography and filmmaking: key, fill, bounce, rim, and kick. Key light shapes the scene, fill light reduces contrast, bounce light reflects off surfaces, rim light outlines subjects, and kick light separates subjects from backgrounds. Master these techniques for stunning visuals! https://cdn.kastatic.org/ka-youtube-converted/vnDk2E4G1sg.mp4/vnDk2E4G1sg.mp4 192 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/exercise-2-light-roles 2025-03-07T16:44:37.328259422Z Activity 2: Lighting an orange (physical) article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/v3-final 2023-07-31T16:40:28.830178554Z Virtual lights Explore virtual lighting tools to experiment with light position, intensity, size, and color. Adjust horizontal and vertical positions, control brightness, and see how light size affects shadows and surfaces. Play with colors from deep red to blue, or choose white for a neutral tone. video https://cdn.kastatic.org/googleusercontent/4W2V9hwHA0yXZ2g6ssXGghjC67layzT1ok8jNXz-2-pkUekraTcIcjjrzWZl8cvZkIH_8Sq_oDjbG4FN6V0rghwX Virtual lights Explore virtual lighting tools to experiment with light position, intensity, size, and color. Adjust horizontal and vertical positions, control brightness, and see how light size affects shadows and surfaces. Play with colors from deep red to blue, or choose white for a neutral tone. https://cdn.kastatic.org/ka-youtube-converted/HpnFBQvwK3A.mp4/HpnFBQvwK3A.mp4 77 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/exercise-3-lighting-an-orange 2025-03-07T16:44:37.328259422Z Activity 3: Lighting an orange (virtual) article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/characterlighting 2023-07-31T16:40:28.830178554Z Character Lighting Pixar uses character lighting to enhance storytelling and evoke emotions. Techniques include rim lighting for drama, underlighting for scariness, and soft light for sadness. Danielle Feinberg and Erik Smitt, Pixar's Directors of Photography for Lighting, share examples from Coco, Incredibles 2, and WALL-E, demonstrating how lighting supports the story and characters. video https://cdn.kastatic.org/googleusercontent/ZuRN3cf4P_D6-OldWeg01hS_C7BtC287x1ohaK4sz64BwyeVP2hQPtoMg38XhBAurWzzcYrCNee3GUA3WTVsC5w Character Lighting Pixar uses character lighting to enhance storytelling and evoke emotions. Techniques include rim lighting for drama, underlighting for scariness, and soft light for sadness. Danielle Feinberg and Erik Smitt, Pixar's Directors of Photography for Lighting, share examples from Coco, Incredibles 2, and WALL-E, demonstrating how lighting supports the story and characters. https://cdn.kastatic.org/ka-youtube-converted/tP7zouXk5k0.mp4/tP7zouXk5k0.mp4 398 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/exercise-4-lighting-a-character 2025-03-07T16:44:37.328259422Z Activity 4: Lighting a character article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/colorscripts 2023-07-31T16:40:28.830178554Z Color scripts Color scripts play a crucial role in Pixar movies, unifying light and color vision before lighting begins. They visually map the film's emotional arc, highlighting key moments and differentiating scenes. By boiling down the story into essential visuals, color scripts enhance storytelling and evoke emotions in the audience. video https://cdn.kastatic.org/googleusercontent/abnnexs8lERoKSa8UP8VOqWwJ516RQJ98E9budn8ohXWfwInMECr0ZrO6IVnkTLQd1OEaPui0JcVNcbx4HwlITJ5 Color scripts Color scripts play a crucial role in Pixar movies, unifying light and color vision before lighting begins. They visually map the film's emotional arc, highlighting key moments and differentiating scenes. By boiling down the story into essential visuals, color scripts enhance storytelling and evoke emotions in the audience. https://cdn.kastatic.org/ka-youtube-converted/J3HGahDdBog.mp4/J3HGahDdBog.mp4 426 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/exercise-5-color-scripts 2025-03-07T16:44:37.328259422Z Activity 5: Color scripts article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/master-light 2023-07-31T16:40:28.830178554Z Master Lighting Master lighting and shot lighting are key stages in movie creation. Color keys guide the lighting team, setting the scene's mood and tone. Master lighting sets up lights for the entire scene, while shot lighting adjusts individual shots. This process helps create visually stunning and emotionally impactful films. video https://cdn.kastatic.org/googleusercontent/KtfoIUg6VvJXlPOInhoRyK2nnXh-8NsrD6nx_gEBq9ABykKOSUZCK9FTioKgCQHGioqW7wko-dlSxGcwCOCjQRI Master Lighting Master lighting and shot lighting are key stages in movie creation. Color keys guide the lighting team, setting the scene's mood and tone. Master lighting sets up lights for the entire scene, while shot lighting adjusts individual shots. This process helps create visually stunning and emotionally impactful films. https://cdn.kastatic.org/ka-youtube-converted/f5ow3UUJ680.mp4/f5ow3UUJ680.mp4 380 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/exercise-6-master-lighting 2025-03-07T16:44:37.328259422Z Activity 6: Master lighting article https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/v/shot-lighting 2023-07-31T16:40:28.830178554Z Shot lighting Shot lighting in animation directs viewer attention, creates depth, and enhances character appeal. Master lighting sets the overall scene, while shot lighting adjusts individual elements. Pixar artists use shot lighting to emphasize characters, improve continuity between shots, and make characters look more appealing from specific camera angles. video https://cdn.kastatic.org/googleusercontent/fj4CXu3rNDbAeUypJ9KrM8WQKyhqN01cttAr21su1Saz8Qk7yiYaOpMPkG0WIjG4HTempni-02J87vJmZdAcdigAhQ Shot lighting Shot lighting in animation directs viewer attention, creates depth, and enhances character appeal. Master lighting sets the overall scene, while shot lighting adjusts individual elements. Pixar artists use shot lighting to emphasize characters, improve continuity between shots, and make characters look more appealing from specific camera angles. https://cdn.kastatic.org/ka-youtube-converted/KOzsvY10ddU.mp4/KOzsvY10ddU.mp4 382 Uses of light and sound https://www.khanacademy.org/computing/pixar/art-of-lighting/introduction-to-virtual-lighting/a/shot-lighting-test 2021-04-29T07:52:13Z Activity 7: Shot lighting article