We need to know how the magnifying glass changes its angle. Magnifier can enlarge the size of an object, but it has no effect on the angle. This means that no matter how many times we use the magnifying glass, we still see the same angle.

Even if we observe the angle of 10 degree with a five-fold magnifying glass, we will still see the angle of 10 degree. A magnifying glass will not change the angle, but only enlarge the image we see.

Magnifier can be divided into the following categories:

1, classified by material: plastic magnifying glass and glass magnifying glass can be classified by material. The glass magnifier includes optical glass magnifier and mineral crystal magnifier.

2. Classification by function: According to function, it can be divided into ordinary magnifying glass and special function magnifying glass. Magnifier with special function includes lamp magnifier, folding magnifier and hand-held magnifier.

3. Classification according to usage scenarios: According to usage scenarios, it can be divided into office magnifiers and outdoor magnifiers. Office magnifiers are generally small and easy to use in the office; Outdoor magnifying glasses are light and easy to carry outdoors.

4. Classification by magnification: According to magnification, it can be divided into low magnification magnifier and high magnification magnifier. Generally, a low-power magnifying glass can magnify an object by 2-4 times, and a high-power magnifying glass can magnify an object by 10-20 times or more.

5. Classification by shape: According to shape, it can be divided into circular magnifying glass, square magnifying glass and rectangular magnifying glass. Circular magnifying glasses are generally beautiful and suitable for decorations; Square and rectangular magnifiers are easier to carry and hold.

6. Classification by use: According to use, it can be divided into jewelry magnifying glass, microscope, astronomical large telescope, etc. Jewelry magnifying glass is mainly used to observe the details and characteristics of jewelry and jade; Microscopes are used to observe the details and characteristics of tiny objects; Large telescopes for astronomy are used to observe celestial bodies and stars.