Lenses are precisely shaped pieces of glass that have been developed and used in corrective glasses, telescopes, microscopes, binoculars, and magnifying glasses.
Convex lenses are objects or shapes that curve or bulge outwards, like a circle or sphere.
Concave lenses are objects or shapes that curve inwards, rather than bulging outwards.
The principal focus of a lens is where light rays appear to converge or to diverge from.
In a ray diagram, a convex lens is drawn as a vertical line with outward facing arrows to indicate the shape of the lens.
The focal length of a lens is the distance between the centre of the lens and the focal point.
Concave lenses are thinner in the middle than they are at the edges, causing parallel rays to diverge.
In a ray diagram, a concave lens is drawn as a vertical line with inward facing arrows to indicate the shape of the lens.
The distance from the lens to the principal focus is called the focal length.
from the lens, the image formed by a convex lens is upright and magnified.
Lenses are precisely shaped pieces of glass that have been developed and used in corrective glasses, telescopes, microscopes, binoculars, and magnifying glasses.
The images formed by a lens can be upright or inverted, magnified or diminished, real or virtual.
Magnification is the process of making an image larger or smaller than the object.
Convex and concave lenses are used in magnification.
Rays from a light source further from the principal axis will result in a smaller image than the object.
Rays from a light source will appear to come from the same side of the principal axis, meaning the image will be upright.
A real image is an image that can be projected onto a screen.
A virtual image appears to come from behind the lens.
A ray diagram is a diagram that represents the direction and angle of travel of light.
To draw a ray diagram, draw a ray from the object to the lens that is parallel to the principal axis.
Once through the lens, the ray should pass through the principal focus.
A ray which passes from the object through the centre of the lens is also represented in some ray diagrams.
Some ray diagrams may also show a third ray.
Convex lenses are objects or shapes that curve or bulge outwards, like a circle or sphere.
The type of image formed by a convex lens depends on the lens used and the distance from the object to the lens.
Magnification is the ratio of the image height to the object height when using lenses.
Cameras and eyes contain convex lenses.
Peep holes are set into doors so the occupant can identify a visitor before opening the door.
Lenses and curved mirrors can produce magnified images.
Ray diagram for an object placed less than one focal length from a convex lens.
Film must be loaded into the projector upside down so the projected image is the right way up.
This works when the object is placed at a distance less than the focal length.
Only the person using the magnifying glass can see the image.
A magnifying glass is a convex lens used to make an object appear much larger than it actually is.
Concave lenses always produce images that are upright diminished virtual.
When a light ray splits up or spreads out on the other side of the lens, it is deflected from a straight path.
In a film or data projector, this image is formed on a screen.
For an object viewed through a concave lens, light rays from the top of the object will be refracted close refracted.
Projectors contain convex lenses.
For a distant object that is placed more than twice the focal length from the lens, the image formed by a convex lens is upright and magnified.