Magnifying glasses - Higher
A magnifying glass is a A lens that is thicker in the centre than at the edges, and which converges light. lens used to make an object appear much larger than it actually is.
This works when the object is placed at a distance from the lens of less than one focal length. The image is:
- on the same side of the lens as the object, but further away;
- upright;
- enlarged;
- virtual.
Ray diagram for an object placed less than one focal length from a convex lens
Only the person looking through the magnifying glass can see the image.
The image cannot be projected onto a screen because it is a virtual image.
The table below summarises the nature of the images produced by a converging lens.
| Distance of object | Size | Orientation | Type | Position | Application |
| Further than 2F | Diminished | Inverted | Real | Between 2F and F | The eye or camera |
| 2F | Same size | Inverted | Real | 2F | |
| Between 2F and F | Enlarged | Inverted | Real | Further than 2F | Cinema projector |
| F | No image because the emerging rays are parallel to the axis | Searchlight. Or follow spot in the theatre | |||
| Closer than F | Enlarged | Upright | Virtual | Same side as object but further away | Magnifying glass |
| Distance of object | Further than 2F |
|---|---|
| Size | Diminished |
| Orientation | Inverted |
| Type | Real |
| Position | Between 2F and F |
| Application | The eye or camera |
| Distance of object | 2F |
|---|---|
| Size | Same size |
| Orientation | Inverted |
| Type | Real |
| Position | 2F |
| Application |
| Distance of object | Between 2F and F |
|---|---|
| Size | Enlarged |
| Orientation | Inverted |
| Type | Real |
| Position | Further than 2F |
| Application | Cinema projector |
| Distance of object | F |
|---|---|
| Size | No image because the emerging rays are parallel to the axis |
| Orientation | |
| Type | |
| Position | |
| Application | Searchlight. Or follow spot in the theatre |
| Distance of object | Closer than F |
|---|---|
| Size | Enlarged |
| Orientation | Upright |
| Type | Virtual |
| Position | Same side as object but further away |
| Application | Magnifying glass |