Become a Member to watch ad-free!
Types of Reflection - Specular and Diffuse
When light hits an object, it doesn’t always behave the same way — it reacts based on the surface.
1. Specular Reflection
This is the fancy, mirror-perfect type of reflection. It happens on smooth surfaces like mirrors or shiny metal. Here, the angle of incidence equals the angle of reflection — or in ninja shorthand: i = r.
Because the reflection is neat and organised, you actually see an image — although it’s virtual, meaning it isn’t a real object floating inside the mirror (sorry, no portal to a mirror universe). It’s just the way the reflected rays appear to come from behind the mirror.
Specular reflection also happens on shiny curved surfaces, though these might bend or distort the image a bit — funhouse-mirror style.
2. Diffuse Reflection
Now imagine light hitting a rough surface — like paper, walls, or your revision notes that have been in your bag for six weeks. The surface is uneven, so the light scatters in many directions. This is called diffuse reflection.
Because the rays spread out everywhere like they’ve had too much coffee, no image is formed. Instead, what you see is the colour of the object, depending on what wavelengths are absorbed or reflected (more on that in another flashcard).
Diffuse reflection is happening all the time — literally everything you see around you right now (apart from shiny things) is thanks to this scattered-light behaviour.
GCSE Keywords: reflection, specular, diffuse, visible light, surface