Answer:
Any converging lens that has a small focal length (several centimeters) can be used as a magnifying glass. The observed object is placed in front of the magnifying glass so that it is located between the lens and the focus (closer to the focus).
Explanation:
It consists of only one condenser lens of small life (a few centimeters).
The observed object is placed between the magnifying glass and its focus (closer to the focus)
The observer sees an upright and enlarged figure of the object.
In order to like clear video ("sharpen"), the magnifier zooms in or out of the subject.
When the character is most clearly seen, we can find ourselves on a given high species.
For a man with normal eyesight, it is about 25 cm.
