Magnifying lens

• A converging lens. Produces upright, virtual, and enlarged objects placed at a distance less than its focal length.
• If object is placed nearer than 25cm to an adult, the image is blurred
• A short-focused magnifying glass produces higher magnification than long-focused one.
• A magnifying glass is often combined with another converging lens achieve greater magnification, and the result is an optical device : the compound microscope.
• The additional lens near the object is called objective.
• The magnifying glass near eye is called the eyepiece
• The objective: pre-magnifies the object by producing real, inverted, and enlarged images which becomes the object for eyepiece
• The eyepiece produces enlarged and virtual image with similar orientation as the object
• to obtain greater magnification, the object is placed near the focal point of the objective
• longer objective= greater magnification
• Viewing in a compound microscope is only possible if the final image is very far from the eyepiece/ at infinity. To achieve this, if the 1st image formed is very near the focal point of the eyepiece
• Microscope was invented by father and son, Hans and Zachrias Janssen in 1590. Where the compound microscope evolved circa 1956