The image formed moves away from the concave mirror when an object is moved from infinity towards the pole of mirror.
The image is diminished when the object is beyond centre of curvature, but it becomes magnified as the object comes within the centre of curvature. The image is of the same size of the object when the object is at the centre of curvature.
For the object situated beyond focus, the image is always real and inverted, whereas for the object situated between the focus and pole the image is upright and virtual.
The table below shows the position, size and nature of the image formed by a concave mirror for different positions of the object.
| No. | Position of the object | Position of the image | Size of the image | Nature of the image |
|---|---|---|---|---|
| 1 | At infinity | At the focus | Diminished to a point | Real and inverted |
| 2 | At very far distance | In focal plane | Highly diminished | Real and inverted |
| 3 | Beyond the centre of curvature | Between the centre of curvature and focus | Diminished | Real and inverted |
| 4 | At the centre of curvature | At the centre of curvature | Same size | Real and inverted |
| 5 | Between the centre of curvature and focus | Beyond the centre of curvature | Magnified | Real and inverted |
| 6 | At focus | At infinity | Highly magnified | Real and inverted |
| 7 | Between the focus and the pole | Behind the mirror | Magnified | Virtual and upright |
