Chapter 2 - Section 5 Optical Tools

Since 1600’s scientists have built many optical tools using lenses. Since 1600’s scientists have built many optical tools using lenses. EX: cameras, telescopes, microscopes. EX: cameras, telescopes, microscopes.

Cameras Camera uses 1 or more lenses to focus light, and film to record an image. Camera uses 1 or more lenses to focus light, and film to record an image. The lens of the camera focuses light to form a real, upside-down image on film in the back of the camera. The lens of the camera focuses light to form a real, upside-down image on film in the back of the camera.

Telescope Telescope forms enlarged images of distant objects Telescope forms enlarged images of distant objects Telescopes use combination of lenses or mirrors to collect and focus light from distant objects Telescopes use combination of lenses or mirrors to collect and focus light from distant objects 2 types of telescopes: refracting and reflecting. Sound familiar?? 2 types of telescopes: refracting and reflecting. Sound familiar??

Microscopes Used to look at small, nearby objects. Used to look at small, nearby objects. Uses a combination of lenses to form enlarged image of tiny objects Uses a combination of lenses to form enlarged image of tiny objects Magnification – ability to make things look larger than they are. Magnification – ability to make things look larger than they are. Resolution – sharpness of an image; the ability to clearly distinguish the individual parts of an object Resolution – sharpness of an image; the ability to clearly distinguish the individual parts of an object

Microscopes cont’d Electron microsopes : Electron microsopes : –early researchers used light microscopes –1930’s scientists developed the electron microscope. –Can be used to view much smaller objects with much better resolution –Use a beam of tiny particles called electrons instead of light