Forming Images with Lenses
Simple demonstration of real and virtual images created using a convex or concave lenses. Basic Rays: If a ray comes into the lens parallel to the axis, it will either pass through F1 (convex) or it will appear to come from F1 (concave). If a ray comes from F2 into the lens (convex) or is aiming at F2 (concave) then it will come out parallet to the axis. If a ray strikes the centre of the lens it will pass straight through. The extra ('many') rays illustrate how other rays travel through the lens. The basic rays are just the easy ones to draw. If the rays of light actually pass through the image, then it is a real image, and could be seen on a screen. If the rays only seem to be coming from the image, then it is a virtual image and can't be seen on a screen - but they can be seen! The image you see with a magnifying glass is a virtual image.