--- title: "Magnifiers, Microscopes and Telescopes" description: "Instruments are built by putting lenses in sequence so that the image of one becomes the object of the next, and angular magnification is what the eye actually notices. A telescope trades field of vie" canonical: https://lightmysky.com/learn/science/magnifiers-microscopes-and-telescopes-mt_f30rUsqYkN source: https://lightmysky.com/learn/science/magnifiers-microscopes-and-telescopes-mt_f30rUsqYkN.md retrieved: 2026-09-12 --- > **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`. # Magnifiers, Microscopes and Telescopes Instruments are built by putting lenses in sequence so that the image of one becomes the object of the next, and angular magnification is what the eye actually notices. A telescope trades field of view for resolution and light collected. Subject: Science · Area: Waves, Light & Sound · Ages 19 to 21 Page: https://lightmysky.com/learn/science/magnifiers-microscopes-and-telescopes-mt_f30rUsqYkN ## Ready when they can - Traces an object through a two-lens instrument and computes the overall magnification - Distinguishes linear from angular magnification and says which matters for a distant object - Explains why a large aperture helps a telescope in two separate ways ## Lesson: Two lenses are better than one A convex lens can work as a simple magnifier. Hold it so the object sits inside its focal length, and you get an image that is upright, enlarged, and virtual. It looks bigger because it fills a wider angle in your eye than the object would at your near point, about 25 cm away. A compound microscope chains two convex lenses. The objective has a short focal length and forms a real, enlarged, inverted image just past its focus. The eyepiece acts as a magnifier on that image, with angular magnification of 25 cm divided by its focal length when the final image sits at infinity. The total is the product of the two: one setup with a 6 mm objective and a 50 mm eyepiece gives minus 186, and the minus means the final image is inverted. A telescope chains two lenses the other way round. The object is so far away that its rays arrive nearly parallel, and the objective forms a small real image at its focal plane. The eyepiece magnifies only that image, so the telescope trades a wide field of view for a bigger angle on a distant thing. What matters here is angular magnification, roughly the objective focal length divided by the eyepiece focal length. **Tip.** A wide aperture helps a telescope twice. It collects more light, so faint objects show up, and its wider opening resolves finer detail. **Recap.** Chain two lenses so the first image becomes the second lens object, and judge the result by the angle it fills in your eye. ## Practice 8 questions on this page, each with its working shown. ## Needs first - [How Telescopes Work](https://lightmysky.com/learn/science/how-telescopes-work-mt_-SZU6cVB_-) - [Curved Mirrors, the Mirror Equation and Real Images](https://lightmysky.com/learn/science/curved-mirrors-the-mirror-equation-and-real-images-mt_7XqB2umthJ) - [Thin Lenses and the Lens Maker's Equation](https://lightmysky.com/learn/science/thin-lenses-and-the-lens-makers-equation-mt_FXOcC5mpIM)