Segments in this Video

Introduction to Lenses (01:19)


Lenses are either convex or concave and rely on refraction to change the direction a light beam is traveling in.

Convex Lenses (03:31)

Learn the definition and see examples of convex lenses. Learn how different factors can affect how light rays interact with convex lenses. Vocabulary includes: focal length, focus, curvature, light source, projector headlight, and refraction.

Convex Lenses: Close Objects (03:44)

The main use of convex lenses is in the formation of images. Learn how different images are produced depending on how close the object is to the lens. Vocabulary includes: object, image, ray, focus, principal axis, reference ray, and virtual images.

Convex Lenses: Distant Objects (04:29)

When the object is farther away from the lens than the focal point, the images produced are upside down and are said to be real. Vocabulary includes: screen, retina, projectors, focal length, magnified, refracts, and reference ray.

Projectors (03:31)

Use a ray diagram to see how slide and older style film projectors work. Learn the different frame per second speeds used by different types of technology.

Modern Projectors (03:08)

Learn how cinema projectors create images. Vocabulary used: Digital Light Processing chip, Digital Micromirror Device, pixel

Producing Color (01:40)

An electronic color image is made up of red, green, and blue pixels. Learn how cinema projectors use prisms and mirrors.

Magnifying and Diminishing Images (02:04)

Learn how the placement of the object affects the size of the image.

The Eye (03:20)

Learn the different parts of an eye and the function of each. Vocabulary includes: sclera, cornea, iris, pupil, lens, vitreous humor, and retina. Graphic images of a fish eye being extracted and dissected.

Perception (04:18)

Learn how the eye processes colors and images. View diagrams showing how the eye uses muscles to move the lens to focus. Vocabulary includes: cone cells, retina, cornea, and near point

Concave Lenses (03:25)

Cameras are examples of concave lenses. Learn why they always produce upright, diminished images. Vocabulary includes: virtual focus, focal length, and principal axis.

Correcting Vision Defects (01:40)

Learn the difference between short sightedness and long sightedness and how glasses fix these vision defects. Vocabulary includes: lens, cornea, retina, and concave.

Short-sighted (02:03)

Use a diagram to explore what happens to images when viewed by a short-sighted person and how concave lenses fix this issue.

Long-sighted (02:43)

Use a diagram to explore what happens to images when viewed by a long-sighted person and how convex lenses fix this issue.

Alternative Vision Correction (01:32)

Learn how contact lenses and laser eye surgery can also correct vision defects. Graphic images of laser eye surgery.

Fast Motion (02:20)

Watch what happens when photos or videos are played back at a faster speed. Vocabulary includes: Time Lapse Photography, Stop motion, and Claymation.

Slow Motion (02:49)

Slow motion playback replays the same frame two to three times. Learn how to achieve high quality slow motion playback and where the term flick came from.

Magnification (03:29)

Learn how to mathematically calculate how far the image is from the lens. Start by using similar triangles to find the equation for magnification.

Focal Length (02:28)

Learn how to use similar triangles to create an equation that solves for focal length. Cross multiply to simplify the equation.

Apply the Formula (02:10)

Given a situation, mathematically calculate the distance from the lens to the image. Learn how positive or negative results for focal length can determine where the object is.

Credits: Shedding Light on Lenses (00:07)

Credits: Shedding Light on Lenses

For additional digital leasing and purchase options contact a media consultant at 800-257-5126
(press option 3) or

Shedding Light on Lenses

DVD (Chaptered) Price: $99.95
DVD + 3-Year Streaming Price: $149.92
3-Year Streaming Price: $99.95



Without lenses, vast areas of human knowledge, from astronomy to microbiology, would never have developed—not to mention photography and the movies! This video uses compelling animation sequences and other visuals to explain how convex and concave lenses produce images in a wide variety of situations. After a concise overview of refraction, the program illustrates how magnifying glasses work and how projectors cast images onto cinema screens. It then looks, quite literally, into a tuna fish’s eye as a basis for showing how vision works. After further explaining how light travels through concave lenses, the film discusses how corrective eyewear helps people who have vision defects. Viewers are also given a chance to consider aspects of slow motion, fast motion, and stop motion imagery, as well as the mathematics of lenses and image formation. (56 minutes)

Length: 57 minutes

Item#: BVL55427

ISBN: 978-0-81608-950-5

Copyright date: ©2013

Closed Captioned

Performance Rights

Prices include public performance rights.