Light and optics links a drawing skill, a description skill and an application skill. The same idea, where the object sits compared with the focal length of the lens, runs through all three.
This cluster is part of the SPM Science learning guide. Each lesson has an original worked example and a self-check.
What does this area cover?
It starts with drawing rays through a convex lens. It then turns the diagram into a description of the image, applies that to cameras, magnifying glasses and spectacles, and ends with reading labelled device diagrams.
How do the parts connect?
The object position is the thread. Position decides the image, the image decides the device, and the device diagram shows where each part sits.
| Lesson | Skill | Link to the next |
|---|---|---|
| Drawing basic ray diagrams | Construct rays | Shows where the image forms |
| Explaining image formation | Describe the image | Sets up device uses |
| Comparing lens applications | Apply to devices | Needs labelled parts |
| Interpreting optical-device diagrams | Read diagrams | Closes the loop |
A short orienting example
A convex lens has a focal length of 10 cm, and an object is placed 25 cm away. Since 2F is 20 cm, the object is beyond 2F.
Rays from the object meet on the far side, between F and 2F (10 cm to 20 cm from the lens). The image is real, inverted and diminished, which is the same set of properties a camera uses.
Who should start where?
If rays never meet where they should, begin with the first lesson. If you can draw but lose marks describing images, go to the second. When you are ready to check everything, use the light and optics practice set.
The lens and image-formation explorer lets you move the object and watch the image change. To work through the cluster with a teacher, see online one-to-one Science tuition.