Forming an Image

Edexcel AS-level PhysicsOpticsLesson 12 of 21

A lens forms an image of an object. There are two kinds of image:

Real image: formed where light rays actually meet after passing through the lens. It can be projected onto a screen, and is always inverted for a single lens.
Virtual image: formed where rays only appear to come from. It cannot be projected onto a screen, and you see it by looking through the lens.

The nature of the image from a convex lens depends on where the object is. Draw a ray diagram with two rays from the top of the object (one parallel to the axis then through F, one straight through the optical centre). The image is where they cross.

More in Optics

• Concave Lenses
• Convex Lenses
• The Power of a Lens
• The Power of Twin Lenses
• Image Calculations
• Magnification
• Plane Polarisation
• Polarising Filters

All 21 lessons in Optics · All Edexcel AS-level Physics topics