--- title: "Ray Diagrams & Images" description: "Construct ray diagrams to show the formation of images by plane mirrors and converging lenses, identifying whether images are real or virtual, magnified or diminished, upright or inverted" canonical: https://lightmysky.com/learn/science/ray-diagrams-and-images-mt_FVERuBoCD1 source: https://lightmysky.com/learn/science/ray-diagrams-and-images-mt_FVERuBoCD1.md retrieved: 2026-10-19 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Ray Diagrams & Images Construct ray diagrams to show the formation of images by plane mirrors and converging lenses, identifying whether images are real or virtual, magnified or diminished, upright or inverted Subject: Science · Area: Waves, Light & Sound · Ages 12 to 13 Page: https://lightmysky.com/learn/science/ray-diagrams-and-images-mt_FVERuBoCD1 ## Ready when they can - Draws an accurate ray diagram for a plane mirror showing a virtual, upright, same-size image - Draws a ray diagram for a converging lens to show image formation - Uses a ray diagram to determine whether the image is real or virtual and which side of the lens it forms - Applies ray diagram knowledge to explain how glasses, cameras, or projectors work ## Lesson: Ray Diagrams and Images A ray is a line with an arrow showing the direction light travels. You already know the law of reflection: both angles are measured from the normal and are equal. To find a plane mirror image, draw two rays from one object point and reflect them using this law. Extend the reflected rays backward with dashed lines. Their extensions meet behind the mirror. This is a virtual image: the reflected rays do not travel there. A plane mirror image is upright and the same size as the object. It is as far behind the mirror as the object is in front, measured perpendicular to the mirror. For example, an object 1 metre in front has its image 1 metre behind. *(drawing: These are drawing steps, not a ray diagram. Repeat them for another object point to locate the rest of the image.)* The axis passes through the lens centre at a right angle to the lens line. For an ideal thin converging lens in air, rays parallel to the axis meet at the far focal point. Focal length, f, is the distance from the centre to either focus. Trace two rays from the same object point: one parallel to the axis, then through the far focus; one straight through the centre. This model treats the lens as one line where rays bend. *(drawing: Both rays start at the same object point. Their crossing, or the crossing of their backward extensions, locates its image.)* If the object is farther from a converging lens than its focal length, rays from each object point meet on the opposite side. The image is real and inverted, so it can form on a screen there. Between f and 2f, the image is larger; at 2f, it is the same size; beyond 2f, it is smaller. Measure these object distances from the lens along the axis. Magnified means larger; diminished means smaller. To calculate image height, multiply object height by the stated size factor. For example, an image three times as tall as a 4 cm object has height 3 x 4 = 12 cm. Height here means size, whether the image is upright or inverted. *(drawing: The image height is three times the object height. The bars compare heights; they do not show ray paths or image orientation.)* If the object is between a converging lens and its near focal point, the outgoing rays spread apart. Extend them backward to find a virtual image on the object's side. It is upright and magnified, as with a magnifying glass over a word. A screen cannot receive this image directly because the outgoing rays do not meet there. At exactly f, the outgoing rays are parallel and no image forms at a finite distance. *(drawing: This sequence records the reasoning. A ray diagram would show the actual paths and their dashed backward extensions.)* A camera can be modelled using a converging lens and a sensor. A distant tree, well beyond 2f, produces a real, inverted, diminished image on the opposite side of the lens. The sensor must be at the image position to record a sharp picture. For a very distant object, this position is close to the far focal point. **Recap.** A plane mirror gives a virtual, upright, same-size image. For a converging lens: beyond f, real and inverted; inside f, virtual and magnified; at f, no finite image. ## Practice 8 questions on this page, each with its working shown. ## Needs first - [Reflection & Refraction](https://lightmysky.com/learn/science/reflection-and-refraction-mt_PifbJOuXrG) - [White Light & Colour](https://lightmysky.com/learn/science/white-light-and-colour-mt_qzGADV-NGe) ## Opens up - [The Camera as an Art Tool](https://lightmysky.com/learn/arts-and-music/the-camera-as-an-art-tool-mt_TIdod5lPOl) - [Refraction and lenses](https://lightmysky.com/learn/science/refraction-and-lenses-mt_u8GKuBMmzC)