Build optics one idea at a time.
Start with the foundations, then explore advanced ideas and calculus at the depth your course needs.
6 of 6 lessons
Curved Mirrors
Use concave and convex mirrors, ray diagrams, and the mirror equation.
Thin Lenses
Model converging and diverging lenses, magnification, and lens power.
Optical Instruments
Build magnifiers, microscopes, telescopes, and the eye.
Single Slits & Resolution
Connect diffraction envelopes with the Rayleigh limit.
Thin-Film Interference
Explain soap colours, oil slicks, and anti-reflection coatings.
Optics Calculus
Differentiate the lens equation and explore image sensitivity near focus.
Change one variable. Watch the physics respond.
Explore 1/f = 1/do + 1/di, then take the idea into the full lessons.
Focus an image
A positive image distance indicates a real image on the far side of the lens.
Everything around the chapter, in one place.
Keep building with practice, classroom presentations, formulae, and a game that puts these ideas to work.
Exam practice
Questions, guided reasoning, and exam-style problem solving.
Browse exam questions →Formula toolkit
Keep the key relationships and their units close to hand.
Review formulae →Members · Classroom presentationClassroom slides
Reveal lesson ideas, examples, and checks in full-screen classroom mode.
Open slides →Lesson files
Find downloadable teaching resources and worksheets in the library.
View files →Focus Rescue
1/f = 1/do + 1/di. Slide lenses and mirrors until a real or virtual image meets the brief.
Play the free chapter game →See it. Read it. Work it.
Connect diagrams to physical relationships and exam reasoning.
Explore diagrams →Guided support
Ask for a hint, check your reasoning, or explore a similar problem.
Ask GioAI →Key ideas to remember
Move without losing your place.
Extra challenging questions
Take the ideas further with course-specific extension questions, supplied-data graphs and worked solutions.